Kidney stones while pregnant

Pregnancy and Kidney Stones

Kidney stones occur in about one of every 1,500 to 3,000 pregnancies-about the same rate as in non-pregnant women of childbearing age. Overall, kidney stones affect about 1 in 11 people-19% of men and 9% of women by age 70.

Kidney stones occur most often in the second or third trimester. The most common sign is pain in the upper abdomen or back and sides, which often spreads to the groin or lower abdomen. Common symptoms include nausea/vomiting, urinary urgency and frequency. Blood in the urine is also a symptom.

Stone formation during pregnancy may be caused by changes to a woman’s body. Late in pregnancy, the bladder is squeezed by the growing fetus. This means pregnant women make many bathroom trips. As a result, they may avoid drinking enough liquids. Lack of fluids may lead to the start of kidney stones.

Diagnosing and treating kidney stones can be done safety, with little risk to the mother or baby. Most kidney stones pass through the body, especially if they are smaller. Larger stones may need treatment. If left untreated, kidney stones may lead to premature labor or interfere with normal labor, which could pose a health threat to the baby.

Treatment of kidney stones in pregnancy ranges from bed rest, pain relievers and getting enough fluids, to threading a very small telescope called a utereroscope into the bladder and kidney to remove or break up a stone.

If you’ve already had kidney stones, the best way to stop future stones is to drink enough liquid-about 3 quarts (ten 10-ounce glasses) a day. Remember to drink more to replace fluids lost when you sweat from exercise or in hot weather. It’s best to drink mostly no-calorie or low-calorie drinks. This may mean limiting caffeinated or alcoholic drinks.

Last Updated on December 19, 2019



Kidney stones can be very painful to bear, especially when you are pregnant. While being pregnant does not increase your chances of getting kidney stones, it makes it complicated to diagnose and administer the usual methods of treatment due to the risks of harming the foetus. While most kidney stones may pass without the need for any treatment, some of them may cause intense pain. In such cases, medical treatment is recommended.



Causes of Kidney Stone During Pregnancy

Although being pregnant does not mean that you are at a higher risk of getting kidney stones, there are certain causes that can connect kidney stones and pregnancy. Some of the common causes of kidney stones during pregnancy are:

1. Lack of fluids: A common reason for kidney stones is the inadequate consumption of water. The lack of fluids in your body causes an increase in the concentration of minerals like phosphorous and calcium in the urine, which leads to the formation of kidney stones. During pregnancy, your body requires more water than usual. Drinking less than the required amount of water may thus lead to kidney stones.




2. Genetic predisposition: The genetic makeup of your body may also increase your chances of kidney stones. If you are from a family with a high incidence of hypercalciuria – a condition where there is an excess quantity of calcium in the urine – you may be more prone to kidney stones during pregnancy.

3. Bowel irritation: If you have gastrointestinal sensitivity, you may be prone to hypercalciuria or be at a higher risk of kidney stones. This is because chronic inflammation in the bowels may increase the number of calcium ions that are deposited on the kidneys, which then turn into crystals.





4. High calcium intake: Pregnant women are encouraged to consume more calcium – this may put extra pressure on the kidneys and cause crystal formation on the kidneys. Also, as your body absorbs a lot of calcium to aid the development of the baby, you may have a higher chance of getting kidney stones.

5. Increased filtration: Due to an increase in the filtration activity of the kidney, the amount of uric acid that you excrete may also increase, which may lead to uric acid stones.




6. Dilation of the uterus: The upper urinary tract may become large during pregnancy, which can cause an incomplete clearing of the urine and increase the risk of kidney stone formation.

7. UTIs: Constant urinary tract infections during pregnancy may be indicative of kidney stones.





Signs and Symptoms

The signs and symptoms of kidney stones during pregnancy aren’t unlike the usual ones. However, there are no specific symptoms that indicate kidney stones and any pregnancy complications caused due to it. Some of the common symptoms of kidney stones during pregnancy include:

1. Pain: Intense pain is one the first and the most common signs of kidney stones. The area of the pain is based on where the stone is, internally. If the stone is in your kidney, you will experience pain in the back, below the rib cage area. Once the stone moves down to the ureter, you will experience pain on the side of your body. As the stone moves further down the ureter, you may even feel pain near your genitals or in the thigh. Apart from this, you may also feel pain in your lower abdomen.




2. Pain during urination: If the stone has travelled down and is stuck at the lower end of the ureter, you are likely to have intense pain while urinating.

3. Blood in the urine: As the stones in the kidney move spontaneously, they may damage the tissues and the cells in the kidney. This may lead to blood in the urine.





Apart from these symptoms, you may also have vomiting, nausea, fever with chills (indicates infection), or may even feel some distension in the abdomen.

How Is Kidney Stone Diagnosed During Pregnancy?

A blood and urine analysis is performed to diagnose kidney stones during pregnancy. A urine test can identify blood, crystals of calcium or uric acid in the urine. A urine culture test can also recognise infection-causing organisms and determine what antibodies they are sensitive to.




A renal ultrasound may be conducted as it is a painless procedure that does not expose the foetus to radiation. However, the drawback of undergoing a renal ultrasound is that it cannot identify certain types of kidney stones and may not be able to identify the cause of an enlarged kidney (whether it is due to pregnancy or due to the obstruction caused by a kidney stone).

X-rays and CT scans are avoided to prevent any damage to the foetus. While an MRI is considered safe as it does not use radiation or contrast materials, it is still not advisable to use it to detect kidney stones during pregnancy.




Indications When Surgical Intervention Is Advised

If natural and conservative remedies do not work, you may have to opt for surgical intervention to get rid of kidney stones under these circumstances:

  • The stones that have obstructed the urinary tract have caused pyelonephritis or inflammation due to bacterial infection
  • If you have only one kidney
  • Acute kidney failure
  • Intense pain
  • Risk of premature labour due to kidney pain

How to Get Rid of Kidney Stones While Pregnant

If you notice any symptoms of kidney stones, it is advisable to consult a urologist for treatment options. Here are some of the methods used to get rid of kidney stones during pregnancy. Treatment methods are also dependent on the nature of your kidney stones and the trimester that you are in.




1. Medical Treatment

Paracetamols are prescribed to relieve pain caused due to kidney stones. However, in the event that medication fails to reduce your pain, or if there is any indication of preterm labour, you may need surgical intervention.


2. Surgical Treatment

  • Ureteroscopy – this procedure is used for diagnosis as well as for breaking down the stones. A small tube called a ureteroscope is inserted into the kidney, which passes through the ureter, the urethra, and the urinary bladder. The process uses a laser to break the stones. This procedure is only ideal for stones smaller than 1 cm.
  • Tube or stent placement – this procedure uses a hollow tube passed through the ureters to drain the urine and the stones. It is minimally invasive and needs local anaesthesia at most.
  • Shockwave therapy and open surgery – these are not prescribed to pregnant women due to risks to the foetus.

3. Natural/Home Remedies

Conservative methods and natural remedies are the most preferred treatment for kidney stones. Some of these include,

  • Intake of water: Drinking at least 8 glasses of water every day can help dilute the minerals and organic salts in the urine. It also helps clear small stones from the kidneys.
  • Fruits: Consuming fruits like watermelon, blueberries, peaches, and other fruits that have high water content is also beneficial.

  • Avoid commercial juices: Packaged juices have a high mineral (and possibly added sugar) and salt content which may make your condition worse.
  • Lemon: Lemon is known to break down medium-sized stones and also open up the ureters, helping the stones pass without much pain.
  • Apple Cider Vinegar: ACV contains acetic acid which dissolved kidney stones. Just adding a tablespoon or two to 1 litre of water and drinking it through the day can be helpful. However, make sure to check with your doctor as the consumption of ACV should be limited during pregnancy.
  • Basil Juice: Like ACV, basil contains acetic acid which can be helpful in breaking down kidney stones. Basil generally helps with inflammation as well. Simply take some fresh or dried basil leaves, boil them in water, and consume the tea. Avoid the prolonged consumption of this tea as it may cause problems like low blood pressure and blood sugar. Always consult with your doctor before trying any home remedy, especially during pregnancy.

Prevention

Some of the best ways to prevent kidney stones are:


  • Drink a lot of water. A minimum of two litres or eight glasses per day is essential.
  • Reduce your salt intake. Avoid junk food especially, as it may contain unhealthy amounts of monosodium chloride.
  • Avoid excess calcium. Keep your calcium intake under 1000 to 1200 mg per day.
  • Talk to your doctor about your medication. Certain medications can make a person susceptible to kidney stones. If you are on medication – any medication, regardless of whether you have been prescribed them during pregnancy – mention them to your doctor. In any case, however, do not stop consuming those medicines without your doctor’s approval.
  • Reduce your consumption of certain foods. Green leafy vegetables, chicken, fish, nuts, beetroot, chocolate, peanuts, beef, red meat, tea, and coffee can make a person more vulnerable to kidney stones.

Kidney stones can occur during pregnancy, and in most cases can be treated using natural treatment methods. However, in case the pain is severe, you will need to opt for medical or surgical treatments to alleviate it. Always remember to reach out to a doctor immediately after you notice symptoms of kidney stones to get the appropriate treatment method and avoid complications.

Also read: Hydronephrosis In Pregnancy

Kidney Stones During Pregnancy

Q1. I am pregnant and I have had a kidney stone. How can I prevent another one and what are the risks to my baby?

— Nikki, Texas

While stones during pregnancy can present a challenge in terms of treatment, in general the presence of the stone itself is not dangerous to the developing baby. The typical approach in such a situation would be to treat stones non-operatively, reserving intervention only for severe obstruction, acute pain, or infection. In the absence of severe obstruction, pain, or infection, the recommendation would be to wait until after delivery to treat the stone. When stones become symptomatic, the least invasive treatment possible is generally selected. Pregnancy itself does not increase your risk of forming a kidney stone. In fact, some common kidney stone prevention measures are not recommended for pregnant women such as specific medications and dietary restrictions. A general rule that anyone can follow to help prevent kidney stones is to increase your fluid intake which dilutes any potential stone-forming elements in the urine. Once the baby has been delivered and the mother has reverted to normal habits, further investigations can be carried out to assess her risk for another stone.

Q2. I am three months pregnant and just found out that I am not supposed to take any cold meds containing phenylephrine. I have been taking Dimetapp and Tylenol Sinus for about a week now. What effects could these medications have on my unborn child

— Jackie, North Carolina

Both of these over-the-counter medications contain phenylephrine as a decongestant. Additionally, Dimetapp contains brompheniramine, an antihistamine. It is very difficult to say for certain what effect these may have, since many medications including these are never fully evaluated in women during pregnancy.

To assist health care workers, the United States Food and Drug Administration and administrative organizations in other countries, such as the Australian Drug Evaluation Committee, have placed most medications into risk groups or categories of potential effects to the fetus during pregnancy, based on all available clinical information. Unfortunately, for most medications, not much is known.

The FDA placed the decongestant phenylephrine in the category C in the pregnancy rating system; which means that “Either studies in animals have revealed adverse effects on the fetus (teratogenic or embryocidal or other) and there are no controlled studies in women or studies in women and animals are not available. Drugs should be given only if the potential benefit justifies the potential risk to the fetus.” Thus it is advised that during pregnancy the decongestant phenylephrine should be avoided.

Antihistamines such as brompheniramine have been reported to be associated with an increased frequency of changes in growth and development of the fetus. The U.S. FDA concluded that alternative antihistamines that can be used during pregnancy are meclizine and cyclizine.

It is always difficult to assess individual risks to the fetus when exposed any medications; however, the highest risk is during the first trimester because the fetus is going through much of its major growth and development.

Both of the medications contained in Dimetapp and phenylephrine in Tylenol Sinus do carry some risk to the development of the fetus. I would recommend that you talk to your obstetrician for alternative medications.

Q3. This seems like such a simple question, but I’m really concerned. Can I safely take Xanax during pregnancy? I’ve heard different things.

— Laura, Alabama

You’ve asked a very important question. It can be a difficult decision whether to continue to take a drug during pregnancy, and often clinical research studies don’t provide clear and concise information regarding the safe use of a medication during pregnancy.

Xanax (alprazolam) is a drug that is often used for the management of anxiety or panic attacks. Because it also causes drowsiness, it is sometimes used to help people sleep when taken before bedtime.

The United States Food and Drug Administration (FDA) divides drugs into five different categories according to how risky it is to take the drug during pregnancy. Under this system, Xanax is in category D, which means it is not recommended for use during pregnancy. Xanax belongs to a class of drugs called benzodiazepines, which if taken by the mother can enter the fetus through the placenta (the organ that transfers nutrients and waste products between the mother and fetus).

You should talk about the risks and benefits of continuing Xanax with your physician and obstetrician so you can make an informed decision. You haven’t said why you are taking Xanax, but your doctor may be able to suggest safer alternatives for you to take during your pregnancy.

Q4. My daughter is bipolar and has become pregnant — are there any safe drugs for her to take for depression while she’s expecting? (She is 36 and has had one miscarriage.)

— Veda, Alabama

That’s a tricky question. Pregnancy can cause major changes in mood and depression, especially for patients who, like your daughter, already have an underlying bipolar condition. Some medications have been tested and are considered safe to continue throughout most of a pregnancy, while others are not. Common antidepressants such as Zoloft and Prozac have been studied extensively and appear to be safe during most of pregnancy, but these medications are more appropriate for depression than bipolar disease. Medications like lithium and Tegretol, often used as mood stabilizers in bipolar patients, have not been studied extensively in pregnancy, so the decision about continuing or stopping them can be a difficult one.

The most important thing for your daughter to do is to consult a high-risk pregnancy expert immediately (developing a medication plan prior to conceiving is best, but since she’s already pregnant she needs a consultation as soon as possible), as well as a psychiatrist who has experience with medications in pregnancy. Depending on their history, some patients can discontinue medications temporarily, or substitute medications that are safer. Your daughter’s history of miscarriage does not affect the choice of medications for her bipolar disease. I hope that helps.

Q5. Is it possible for me to have an embryo transplant at age 53? I am healthy and only have minor arthritis. I am also menopausal. My husband and I really want to do this. Thanks so much.

— L., Indiana

In vitro fertilization is a procedure in which one or more eggs fertilized in the laboratory are transferred to the uterus of a woman who has been hormonally treated to prepare her for the procedure. Embryo transplants can technically be performed in someone your age, but there are several limitations. First, the eggs used to make the embryos would have to come from a donor since ovarian function has decreased by a woman’s late 40s. Second, the uterus of a 53-year-old woman is not going to respond as well to the hormonal preparation as a younger woman’s would; if the uterine lining does not build up appropriately the donor embryos will not implant. Unfortunately, the chance of the embryos implanting is relatively small in a 53 year old.

Finally, the medical complications of a pregnancy at age 53 are significantly higher than average. It has been done before, but the chance of a successful outcome, given all the limitations, is slim.

Learn more in the Everyday Health Pregnancy Center.

Kidney stones during pregnancy are rare. However, they impact roughly 1 in 1500 pregnant women and are a common cause of non child birth related abdominal pain during pregnancy.

Women go through major changes in their renal tract during pregnancy. Significant dilation occurs in the pelvic region and their ureters (pathways from kidneys to bladder- see photo below) also expand. Additionally, Progesterone (a hormone released by the ovaries) relaxes muscles and slows down the natural-involuntary constriction/relaxation of the urinary tract that typically is responsible for moving urine out of the kidneys to the bladder and out of the urethra 1. Blood flow and the rate of filtered fluid through the kidneys both also increase by over 50% during pregnancy 6.

This up-tick in flow leads to increased urinary excretion of calcium, uric acid, sodium, and oxalate, all of which are stone promoting (lithogenic) 7,8. To further complicate things, calcium reabsorption is also reduced during pregnancy due to suppression of the parathyroid hormone. These changes, combined with slower urine movement through the urinary tract due to the Progesterone mentioned above, lay the foundation for stone formation during pregnancy.

In the general population, calcium-based stones account for over 80% of kidney stones. Calcium-based stones are also the most commonly formed stones during pregnancy 10,11. However, up to 74% of pregnant women with kidney stones have calcium phosphate stones. This is in contrast to the general population where calcium oxalate stones are more common. The prevalence of calcium phosphate kidney stones over calcium oxalate kidney stones in pregnant women is thought to be related to the alkaline pH of urine that women experience during pregnancy and the increased excretion of stone promoting minerals as mentioned in the previous paragraph 11,12.

The incidence of kidney stones in pregnancy is quoted to be roughly 1 in 1500 9,17,18. Kidney stones also appear to be more common in women who have had more than one child with 80-90% of kidney stones occurring in the second or third trimester 19-22. Kidney stones are found twice as often in the ureter (pathway from kidney to bladder- see photo above) as stones found in the kidneys during pregnancy 20. And, according to the most recent statistics, women experiencing kidney stones during pregnancy are more likely to be Caucasian and have a history of renal disease and hypertension. A quarter of these women also will have had previous kidney stones 20,23,24.

For most pregnant women, their realization of the kidney stone(s) presents itself as severe flank pain in the area surrounding the kidneys with pain radiating toward the groin 25. It is also common for nausea and vomiting to occur. Most women will also experience painful urination as the stone makes its way from the kidney through the ureter to the bladder. Once in the bladder, they will experience a sensation of pressure and the urge to urinate will also increase as the body attempts to remove the foreign object (the kidney stone).

One concern that women must be aware of is that kidney stones may also present themselves as pre-term labor or as contractions 17,19. In one study, nearly 28% of women were incorrectly diagnosed with afflictions ranging from appendicitis to diverticulitis to placental abruption 20.

Presence of kidney stones in pregnant women has been associated with a significant increase in the risk of the following conditions:

  • Recurrent Miscarriage: three or more consecutive miscarriages.
  • Mild Pre-eclampsia: condition during pregnancy characterized by high blood pressure.
  • Chronic Hypertension: long-term high blood pressure
  • Gestational Diabetes Mellitus: a form of high blood sugar affecting pregnant women
  • Caesarean Deliveries: procedure where baby is delivered through an incision into the mother’s abdomen (belly) and uterus (womb). Commonly referred to as a “C-Section.”

Kidney stones have also been associated with premature rupture of membranes in one study 23. Rates of premature births in conjunction with kidney stones have been cited between 2.5-40% 17,18,20,23,27. This is a pretty big range and findings have not been consistent in studies. Since data is conflicting amongst different studies, the true risk of kidney stones during pregnancy is difficult to ascertain.

If you are pregnant and are concerned that you may have kidney stones, a dipstick analysis of mid-stream urine should be performed to look for underlying infection. Urine with a pH of greater than 7 is considered to be alkaline and may suggest infection with a urea-splitting organism (these are the bacteria that we discussed in our last post about Struvite Kidney Stones). Urine with a pH of less than 5 is acidic and may be associated with uric acid stone creation. Additionally, if the dipstick test comes back positive for nitrites, your doctor should perform a urine culture and send it off for analysis to determine if an infection is present or if there is any microorganism involvement (bacteria).

Your doctor should also check your blood for a anemia, kidney function, and any abnormalities in electrolytes (including calcium). If increased serum calcium levels are observed, your doctor should investigate for Hyperparathyroidism (increased levels of parathyroid hormone in body which is responsible for regulating blood calcium levels).

Unfortunately, the use of traditional kidney stone scanning technology such as CT scans and X-Rays are discouraged during pregnancy due to the presence of ionizing radiation’s impact on the fetus. The use of Ultrasound equipment is safe. But, Ultrasounds have poor sensitivity when it comes to kidney stone detection 19,20,35-37. One way to improve detection rates with Ultrasound technology is to have the scan conducted trans-vaginally (transducer inserted into the vagina) 41. Traditionally, Ultrasounds are conducted trans-abdominally (transducer used outside of the body over the abdomen). Trans-vaginal scans are reported to be roughly 7 times more effective than trans-abdominal.

Another potential option for kidney stone detection while pregnant is through the use of magnetic resonance imaging (MRI), commonly referred to as magnetic resonance urography (MRU) when related to the urinary tract. An MRI uses electromagnetic radio waves rather than ionizing radiation (like with X-Rays and CT Scans). No harmful effects to the fetus have been reported. However, it is suggested to be avoided during the first trimester 48. One downside to the use of MRI technology when scanning for kidney stones is that the scan does not specifically identify kidney stones. It merely suggests certain features that may suggest the presence of a kidney stone 50. Kidney stones often appear as signal voids (see photo below).

The lack of accurate scanning technology and limited treatment options leaves doctors and the pregnant women dealing with kidney stones in a difficult situation. Because of this, most doctors choose a course of inaction due to the potential complications of action. Fortunately, roughly 68% of stones less than 5mm in size will be passed spontaneously within 4 weeks. Larger stones (5-10mm in size) also have a decent chance of passing spontaneously at a rate of roughly 47% 31,56,57. We will discuss stones that are too large to pass on their own below.

The best course of action relating to kidney stones during pregnancy is always going to be prevention. But, often times, we don’t know what we don’t know until we… well, know. So, let’s discuss a few topics key to the management of kidney stones in general and their implications during pregnancy:

  1. Hydration: This is one area that is universal and will not impact pregnancy. The more hydrated you are, the better chance you have at not forming kindey stones. Urine should be clear to a slight yellow tint at the most (see photo below).
    • The more water (H2O) in your system, the better chance this molecule has at binding with the major stone forming molecules such as oxalate, phosphate, and uric acid and simply pass them out with your urine. If you are dehydrated, these molecules tend to stack upon each other and turn into kidney stones. STAY HYDRATED! This goes for before, during, and after pregnancy.
  • Pain Relief: Your willingness to accept pain medications and/or the type of pain medication will be directly correlated to your views on the impact of said medication on your developing child. Generally, it is discouraged to take pain medications during pregnancy due to the potential implications for the fetus.
    • However, some medications such as Acetaminophen and even Opiods, are generally considered “safe” during pregnancy. We say “safe” because your personal view point on medication/drugs/pharmaceuticals will sway this one way or another as mentioned previously. Unfortunately, most find acetaminophen ineffective in managing pain of kidney stones (pregnant or not).
    • Opioids are VERY effective for pain. But, again, if you prefer a more natural approach- you will most likely shy away from these. We will defer further commentary here as to the options and urge a conversation with your doctor regarding the risks.
  • Inflammation: When your body is dealing with a kindey stone, inflammation is rampant in the urinary tract. And, this makes sense, as your body is trying to rid itself of a foreign object. However, immflamation slows everything down when it comes to passing a kidney stone. In order for kidney stones to pass, the stone requires a free-flowing path. Or, at least a path with the least amount of resistance possible. Just as with pain medication, your view point for or against anti-inflammatory medication will impact your decision regarding this particular facet of kidney stone management.

    • Just like for pain relief, Acetaminophen is considered “safe” and can also help decrease inflammation. This is one use case where this medication may prove of some use; as it typically falls short on the pain management side for kidney stones.
    • Unfortunately, many of the potent and natural herbal remedies for inflammation are generally regarded as “un-safe” for use during pregnancy.
  • Urine Flow: Increasing the rate of urine flow is key to kidney stone passage as it will speed up the stone’s movement. Low urine flow will not create adequate pressure to prompt the stone to move. You might think that keeping the stone where it is would be a good thing. But, it isn’t. A stationary stone can cause a whole host of other complications that are best avoided (pregnant or not). Increased urine flow can be accomplished two ways. First, through drinking more water and second through the use of diuretics.
    • For the general population, utilizing both increased fluid intake and a diuretic will exponentially speed up kidney stone passage. However, for pregnant women, the use of a diuretic (pharmaceutical or herbal) is generally not recommended. The implications with a pharmaceutical option should be obvious to those concerned (un-natural/chemical/etc) and herbal options are also discouraged due to other potential interactions with the pregnancy.
    • So, our suggestion would be to adopt the increased water consumption option. Getting on a schedule can be very helpful with this (for example: setting a time for every hour where you consume an 8oz glass of water during waking hours- please note that ounces consumed per hour should vary with relation to the size of your body).
  • Citrate: In addition to increased water consumption, adding naturally occurring citrates to your diet will most likely be the most impactful thing that you can do prior to and during your pregnancy with regards to kidney stones. We say naturally occurring citrates because citrates can come in many forms. But, not all are created equal. We recommend using the juice of 1-2 whole organic lemons (because they’re sweeter than conventionally grown lemons) to 16oz of water daily. This can be done with the juice of one lemon consumed in the morning and one in the evening.
    • Lemon juice from bottles, concentrates, or powders (freeze-dried raw powders are ok) are not recommended as these have been pasteurized and the levels of citrate have been decreased substantially and are not as bioavaiable.
    • Same thing applies to citrate supplements such as magnesium citrate, calcium citrate, and others. When citrates are present in the urine, they bind with all of the lithogenic (stone forming) minerals in the body and simply pass in the urine. Look at citrates as a booster to proper hydration. Water (H2O) molecules will take one portion and citrate takes the other. In essence, spreading the load when it comes to preventing kidney stone crystals from forming. Lemons are completely safe to consume during pregnancy and also have added benefits when it comes to kidney stones:
      • Acidity can help break down and erode any current kidney stones
      • Lemons have anti-inflammatory properties that can assist with pain relief and reduce inflammation in the urinary tract.

To help summarize the previous section and put it into context for pregnant women who may be currently dealing with a kidney stone, we recommend increasing water intake (to the point of clear to slight yellow tint-see above chart) and adding naturally occurring citrate to your diet. If you utilize these two suggestions, you will put yourself in the best position to deal with your kidney stones in as natural of a fashion as possible with the least potential impact to the fetus.

Now, for any pregnant women with stones that are too large to pass on their own (typically 10mm or larger or Staghorn structure) or with stones that are causing an obstruction, a more active management plan may be required to solve the issue. An estimated 25-40% if pregnant women will require active intervention of some sort 17,19-21,23. We will provide a brief description of the current options below. Please note that the following is best discussed with your doctor, urologist, obstetrician, anesthetist, and neonatologist team due to the complicated nature of this type of invasive interaction during pregnancy.

  • Ureteral Stent: insertion of a stent (SEE BELOW PHOTO) into the ureter to temporarily open the passage for the stone to travel to the bladder and out of the body. Typically performed under local anesthesia.
  • Percutaneous Nephrostomy (PCN): creates a temporary diversion of urine through a tube inserted directly into the kidney. Typically performed under local anesthesia. (see photo below)
  • Ureteroscopic Stone Removal (URS): surgeons use an endoscope in combination with either a laser or ultrasonic lithotripter (concentrated sound waves to break up stone) and a retrieval basket to remove the stone(s). A stent is typically inserted during surgery to encourage any remaining fragments to pass freely. URS may be performed under general or spinal anesthesia or even sedation. (see photo below)

To conclude, diagnosis and treatment of kidney stones during pregnancy is a complex problem. Risks to the developing child from ionizing radiation and invasive intervention procedures must be balanced with clinical care for the mother. Ideally, the mother dealing with kidney stones during pregnancy would have a team consisting of medical professionals from every area of practice related to her situation.

Prevention is the key though. So, start early. Especially if you have formed kidney stones in the past. Ensuring that your body is properly hydrated will go a very long way. And, adding in naturally occurring citrates will help boost prevention.

For more information, please reach out to us directly or consult your physician.

1 Marchant DJ. Effects of pregnancy and progestational agents on the urinary tract. Am J Obstet Gynecol 1972; 112: 487–501.

7 Smith CL, Kristensen C, Davis M, et al. An evaluation of the physicochemical risk for renal stone disease in pregnancy. Clin Nephrol 2001; 55: 205–211.

8 Maikranz P, Parks JH, Holley JH, et al. Gestational hypercalciuria causes pathological urine calcium oxalate supersaturations. Kidney Int 1989; 36: 108–113.

9 Coe FL, Parks JH, Lindheimer MD. Nephrolithiasis during pregnancy. N Engl J Med 1978; 298: 324–326.

10 Maikranz P. Nephrolithiasis in pregnancy. Baillieres Clin Obstet Gynaecol 1994; 375: 375–386.

11 Ross AE, Handa S, Lingeman JE, et al. Kidney stones during pregnancy: An investigation into stone composition. Urol Res 2008; 36: 99–102.

12 Meria P, Hadjadj H, Jungers P, et al. Stone formation and pregnancy: Pathophysiological insights gained from morphoconstitutional stone analysis. J Urol 2010; 183: 1412–1418.

17 Drago JR, Rohner TJ, Chez RA. Management of urinary calculi in pregnancy. Urology 1982; 20: 578–581.

18 Hendricks SK, Ross SO, Krieger JN. An algorithm for diagnosis and therapy of management and complications of urolithiasis during pregnancy. Surg Gynecol Obstet 1991; 172: 49–54.

19 Butler E, Cox SM, Eberts EG, et al. Symptomatic nephrolithiasis complicating pregnancy. Obstet Gynecol 2000; 96: 753–756.

20 Stothers L, Lee L. Renal colic in pregnancy. J Urol 1992; 148: 1383–1387.

21 Parulkar BG, Hopkins TB, Wollin MR, et al. Renal colic during pregnancy: A case for conservative treatment. J Urol 1998; 159: 365–368.

23 Swartz MA, Lydon-Rochelle MT, Simon D, et al. Admission for nephrolithiasis in pregnancy, risk of adverse birth outcomes. Obstet Gynecol 2007; 109: 1099–1104.

24 Jones WA, Correa RJ, Jr, Ansell JS. Urolithiasis associated with pregnancy. J Urol 1979; 122: 333–335.

25 Eskelinen M, Ikonen J, Lipponen P. Usefulness of history-taking, physical examination and diagnostic scoring in acute renal colic. Eur Urol 1998; 34: 467–473.

27 Chung SD, Chen YH, Keller JJ, et al. Urinary calculi increase the risk for adverse pregnancy outcomes: A nationwide study. Acta Obstet Gynecol Scand 2013; 92: 69–74.

35 Lifshitz DA, Lingeman JE. Ureteroscopy as a first line intervention for ureteral calculi in pregnancy. J Endourol 2002; 16: 19.

36 Denstedt JD, Razvi H. Management of urinary calculi during pregnancy. J Urol 1992; 148: 1072–1075.

37 Isen K, Hatipoglu NK, Dedeoglu S, et al. Experience with the diagnosis and management of symptomatic ureteric stones during pregnancy. Urology 2012; 79: 508–512.

41 Laing FC, Benson CB, DiSalvo DN, et al. Distal ureteral calculi: Detection with vaginal US. Radiology 1994; 192: 545–548.

48 Kanal E, Barkovich AJ, Bell C, et al. ACR guidance document for safe MR practices. Am J Roentgenol 2007; 188: 1447–1474.

50 Spencer JA, Chahal R, Kelly A, et al. Evaluation of painful hydronephrosis in pregnancy: Magnetic resonance urographic patterns in physiological dilatation versus calculous obstruction. J Urol 2004; 171: 256–260.

56 Gettman MT, Segura JW. Management of ureteric stones: issues and controversies. Brit J Urol Int 2005; 95: 85–93.

57 Preminger GM, Tiselius HG, Assimos DG, et al. Guideline for the management of ureteral calculi. Eur Urol 2007; 52: 1610–1631.

Kidney Stones during Pregnancy

Most of these stones are relatively small and over two-thirds will pass out spontaneously in the urine. Those that do not pass easily, can cause obstruction and pain and can induce premature labor leading to abortion. Giving anesthesia to treat such stones by endoscopic procedures too has similar hazards.

The colicky pain of kidney stones can mimic the pain of appendicitis, placental detachment or diverticulitis hence diagnosis becomes difficult clinically without any investigations. Not diagnosing the condition in time, can lead to complications like obstruction and infection of the kidney and this can create an emergency situation. All this means that immediate care is important when a stone is suspected.(1✔)

The risk of kidney stones in pregnancy is estimated to be about 1 in 1500 and is similar to non-pregnant women. However this incidence may be rising due to the rise in global temperature.

Why do Kidney Stones form during Pregnancy?

The kidneys are the filtering units of the body. They are two bean shaped organs present just below the rib cage, one on either side of the spinal column. Blood carrying impurities gets filtered after entering the kidneys; this process results in urine formation. The urine drains from the kidney, passes through the ureters and into the urinary bladder. Urine is then voided out through another small tube called the urethra.

The urine is a mixture of waste chemicals and minerals. These chemicals sometimes form small crystals which then fuse together to form kidney stones.(2✔)

Kidney stones are medically also called ‘Urolithiasis’ (Uro-related to urology and lithiasis in Latin means stones). It is a condition where stones are found in the urinary tract, which includes the kidneys, ureters or the urinary bladder. They range from microscopic crystals to stones as large as 3-4 cm.

Women could be more prone to developing kidney stones during pregnancy for the following reasons:

a. Urinary calcium excretion increases during pregnancy. This is due to increased absorption of calcium from intestine, increased re-absorption of calcium from bone and due to the hormonal effects of the parathyroid hormone. Since more calcium reaches the kidneys, it has the possibility of precipitating and forming stones, especially if the woman does not drink enough water.

b. As kidney filtration increases in pregnancy, there is also increased excretion of uric acid, which could increase the chances of uric acid stones.

However, substances that inhibit stone formation are also excreted in the urine to a greater extent during pregnancy. Therefore, the overall risk for kidney stone development is not increased during an otherwise normal pregnancy.(3✔)

What are the Risk Factors for developing Kidney Stones during Pregnancy?

Risk factors for developing kidney stones during pregnancy include the following:

  • Middle-age between 30-50 years
  • Continuous exposure to hot and dry climate (like in farm workers and laborers)
  • Decreased water intake and subsequent decreased urinary output. This leads to increased saturation of the urine with calcium and other minerals
  • Presence of a family history of kidney stones
  • Intake of foods rich in calcium, sodium and red meat
  • Obesity
  • Presence of inflammatory bowel disease (Crohn’s disease and ulcerative colitis)
  • Presence of spinal cord disorders
  • Hyperparathyroidism
  • Presence of birth defects or abnormality in the structure of the kidneys, ureters or urinary bladder

What are the Symptoms and Signs of Kidney Stones?

Generally the symptoms and signs of kidney stones during pregnancy are similar to those caused by kidney stones at other times.

Pain is one of the commonest symptoms of kidney stone and the site of pain depends on the location of the stone. If the stone is in the kidney the pain is usually fixed to the back region below the rib cage. However if the stones move down the ureter, the pain will radiate down towards the side of the body.

  • Flank pain or back pain –
    • The pain starts suddenly and is severe in intensity. The degree of pain depends on the extent to which it causes obstruction
    • Once the stone moves down to the ureter – the pain radiates from the flank to the groin or to the inner side of the genitalia or labia or even go down the thigh
  • Lower abdominal pain – The pain should be differentiated from other conditions like appendicitis and placental abruption
  • Pain while passing urine especially towards the end – this means the stone has traveled down but still stuck in the lower end of the ureter
  • Blood in the urine – maybe frank blood or maybe seen only under microscope
  • Nausea, vomiting
  • Fever with chills or rigors – indicates possibility of infection
  • Occasionally, distension of the abdomen

How do you Diagnose Kidney Stones during Pregnancy?

Investigations used to diagnose kidney stones in pregnancy include the following:(4✔)

Blood and urine tests:

  • Urine analysis may reveal blood in the urine, as well as other features calcium or uric acid crystals
  • Kidney function tests: Serum urea, serum creatinine are raised and eGFR (estimated glomerular filtration rate) is reduced if there is damage to kidneys
  • Urine culture and sensitivity identifies the organisms causing urine infection, and the antibiotic to which they are sensitive to. Infections may occur following obstruction to the urinary flow caused by the kidney stones
  • Complete blood picture and CRP (C reactive protein) detect inflammation or infection in the body
  • Changes in serum electrolytes like increased potassium and decreased serum bicarbonate levels indicate kidney tubular acidosis
  • Serum calcium may be elevated in hyperparathyroidism
  • Serum uric acid may be elevated, predisposing to kidney stones

Imaging studies in Pregnancy

a. Renal Ultrasound: Kidney ultrasound with or without doppler studies is the primary imaging investigation. It is cheap, easily available, can be done without pain and radiation exposure to the fetus, and without injecting any allergenic contrast material into the patients. Doppler studies help to evaluate the kidney blood vessels, which can give clues to the presence of an obstruction in the urinary tract. The disadvantage of using ultrasound is that it cannot identify some types of kidney stones, and cannot differentiate enlarged kidneys due to normal pregnancy or obstruction from a stone.(5✔)

For stones in the lower end of the ureter, which cannot be visualised on a regular ultrasound, a trans-vaginal ultrasound (the ultrasound probe is inserted through the vagina) may be helpful

b. X-Rays and CT-scans – Plain CT scan to diagnose stones in the urinary tract is currently the gold standard test and is routinely performed in all such cases. However it is best avoided during pregnancy due to the effects of ionizing radiation on the unborn fetus. The risks to the unborn baby of radiation are more during the first six months of pregnancy when there are rapid divisions of cells. Hence these tests are best avoided. If they are done the risk should be explained to the parents.

Many experts have the view that the risks of cancer or genetic defects are minimum if the radiation exposure is less 50 mGy (mGy – is unit of radiation and stands for milligray. One milligray is equal to one thousandth of a gray and the gray is defined as the absorption of one joule of ionizing radiation by one kilogram of matter, e.g. human tissue)

An X-ray of the abdomen produces an exposure of 4.2 mGy whereas a CT scan causes exposure of 49 mGy.

If x-ray or CT is planned for diagnosis of the stone, the radiologist will reduce the fetal radiation exposure to the minimum by keeping the exposure time or number of x-rays to the least required. They will also use lead shields to protect the maternal pelvis.(6✔)

c. Role of Limited IVU (intravenous urogram) – If ultrasound has been unsuccessful in identifying the stone but the presence of stones is strongly suspected and CT scan is not available – a limited IVU without using full dose of radiation can be done. An x-ray of the kidney, ureters and bladder are taken first, then contrast material is injected and another x-ray is taken after 30 minutes.

c. Magnetic Resonance Imaging (MRI): MRI does not use radiation or contrast materials, hence it is safe but is normally not advised in the first trimester. Though stones may not be identified directly, MRI can identify the point of obstruction.

What are the Indications for Surgical Intervention in Pregnant Women with Kidney Stones?

Surgical intervention is advised when conservative management fails. Indications are:

  • Stones causing obstruction of the urinary tract leading to pyelonephritis or sepsis of the kidneys
  • Obstruction in a patient having only one kidney
  • Acute kidney failure
  • Severe pain
  • Premature labor triggered by kidney pain and not settling with labor suppressant drugs

What is the Treatment of Kidney stones in Pregnancy?

The goal of treatment should be to minimize the symptoms in the mother, to prevent kidney damage and sepsis, and to minimise risk to the foetus.(7✔)

Hospital admission is advised.

Conservative management should always be provided first. This includes:

  • Bed rest
  • IV fluids
  • Pain killers/analgesics
  • Antibiotics
  • Anti-nausea/vomiting medication

With this, approximately 70-80% stones will spontaneously pass out or the symptoms would settle down sufficiently for surgical procedures to be delayed for later/until after delivery.

The surgical procedures will require anesthesia, and the procedures generally advocated are the following:

  • Ureteroscopy: A small diameter tubular telescope is passed into the ureters via the urethra and the urinary bladder. This is both a diagnostic as well as a therapeutic procedure. Stones can be easily identified and removed at the same time. Advantages include the use of single surgical procedure for the diagnosis as well as the treatment, the quick resolution of symptoms and avoidance of stent or nephrostomy tube-related complications. Laser is the preferred source to break the stone if required.
  • Ureteral stent placement: A hollow, soft silastic tube is placed into the ureter under cystoscopy guidance. This helps to temporarily relieve the obstruction and the drain out the urine. The stents have to be replaced every 2 to 3 months. Definitive treatment is then delayed until after delivery.
  • Percutaneous nephrostomy: A small tube is placed into the kidney through the skin. This helps with quick decompression of the kidney, rapid control of pain and resolution of the infected enlarged kidney.
  • Open surgery or ESWL (shockwave lithotripsy) is not routinely advised in pregnant women.

How can Kidney Stone Complications be Prevented in Pregnancy?

Kidney stone complications during pregnancy can be prevented by:(8✔)

  • Increasing fluid intake (around 2 litres/day)

  • Reducing salt intake
  • Reducing the consumption of foods like chicken, fish, red meat, beef, peanuts, chocolate, nuts, green leafy vegetables, coffee, tea and beetroot
  • Avoiding excessive calcium intake. The daily recommended dose of calcium should not exceed 1000-1200 mg/day. Conversely, very low calcium diets are also not advised

Health tips

  • High citrate content of lemon juice and citrus fruits inhibits stone formation
  • Limit intake of high salt and sugary food
  • Limit alcohol intake as it can cause uric acid stones
  • Eating more fruits and vegetables will reduce urine acidity and stone formation.
  • Women who have kidney stones or are at high risk for kidney stones may be advised to undergo diagnostic tests and kidney stone removal before planning pregnancy

Preventing kidney stones is essential to avoid
complications during delivery or damage to the foetus.

In any condition, kidney stones can be a pain in more ways than one. But having a kidney stone during pregnancy can be a double whammy since the regular problems of child-bearing are compounded. It is important to clarify, however, that pregnant women are not more prone to developing kidney stones. The issue is simply that diagnosing and treating a woman with a kidney stone is more difficult due to the chances of the foetus being harmed. By itself, though, kidney stones are not harmful for the developing baby.

Kidney stones are hard deposits or crystals of minerals and salt that form in the kidneys. These can then move to other parts of the urinary tract. Such stones can vary in size. A small one can pass through the bladder without any problem or pain. But a medium-sized or large stone could lodge along the ureter, leading to severe pain or even bleeding, requiring medical attention.

Causes and Symptoms

Generally, dehydration is a prime cause in kidney stone formation. In a dehydrated body, fluids pass slowly via the kidneys, raising the risks of salts and minerals colliding and binding to each other. Kidney stones are also formed if the urine contains high amounts of calcium, oxalate, phosphate, uric acid and other trace elements. Foods rich in oxalate (beetroot, spinach, chocolate, most nuts and tea) and phosphate (colas) also contribute to stones and should be avoided or consumed minimally.

People with a family history of stones, recurring urinary tract infections, urinary tract blockage (which may occur during pregnancy due to the pressure of the baby on the kidneys), digestive issues, those consuming more colas than water and even women with type 2 diabetes can be more prone to kidney stones.

The symptoms of stones can include pain while urinating, blood in the urine, cloudy or smelly urine, intense pain in the back, lower abdomen or side and accompanying nausea and vomiting. Other tell-tale signs comprise the urge to urinate frequently, passing only small amounts each time as well as fever and chills (indicating infection). Complications from kidney stones during pregnancy may include preterm delivery, gestational diabetes, preeclampsia and other hypertensive issues.

An analysis of blood and urine can determine the presence of kidney stones during pregnancy. Urine tests can detect the presence of blood, calcium crystals or uric acid. CT scans and X-rays are, however, not advisable during pregnancy due to the risk of foetal damage from radiation.

Treatment and Prevention

Typically, treatment depends on their size. While small stones may pass out on their own, daily hydration and medications can also be used to expel stones. In the case of large stones, these can be extracted through surgery. Whereas sound wave lithotripsy is used in the case of normal women to break up stones, it cannot be done during pregnancy as this may harm the baby.

Medications can be administered to control the pain while surgery is done under anaesthesia, ensuring the mother and unborn baby are unhurt during the procedure.

While preparing for pregnancy, all preventive measures must be taken against kidney stones:

Drinking water: Drink 8-10 glasses of water and other liquids daily. Remember, the body requires more water during pregnancy.

Decreasing salt intake: Limit salt intake. Avoid processed, packaged and junk foods high in sodium.

Reducing animal protein: Amino acids and trace elements in protein can promote stone formation.

Limiting calcium consumption: Although calcium supplements are recommended in pregnancy, women with kidney stones need to be watchful, minimising intake.

Despite precautions, if a woman displays the following symptoms, call a doctor immediately:

  • Pain in the back, abdomen or side not controlled by painkillers.
  • Bright-red blood in the urine.
  • Nausea and vomiting that is unresponsive to medication.
  • Watery discharge or vaginal bleeding.
  • Cramps or painful contractions lasting more than four hours.
  • Decreased or minimal foetal movement.
  • Temperature exceeding 100-degree Fahrenheit.

Although kidney stones are not fatal per se, they can lead to kidney infection. In turn, this can cause sepsis. Septic shock or sepsis can arise from any infection in the body, including influenza, pneumonia or urinary tract infections. Globally, sepsis results in almost 33% fatalities.

Moreover, in the third trimester of pregnancy, kidney stones could induce labour pain. Therefore, it is best to take all precautions in avoiding unwanted complications from kidney stones during pregnancy.

They say the only thing comparable to giving birth is kidney stones, so what happens when you have to experience both?

Fun fact: Kidney stones have been found in Egyptian mummies as old as 7,000 years old.

Not-so-fun fact: During pregnancy, kidney stones are more likely to develop during the last few weeks of pregnancy, meaning if you’re pregnant and you get one, you’ll have two very painful things squeezing their way out of your body.

While kidney stones are relatively rare during pregnancy, affecting about only one in 1,500 pregnancies, the extra calcium that many women consume while pregnant combined with a decreased ability of the kidneys to process that calcium can put some preggos at risk for developing the fun of a kidney stone.

Younger women, in general, are at less risk of developing kidney stones than men (hence why the menfolk insist on comparing kidney stones to childbirth — I’m still not buying it). “The rate is similar to reproductive-aged women who are not pregnant,” notes Lisa M. Valle, D.O., with Saint John’s Health Center in Santa Monica, California. However, certain lifestyle and genetic factors, such as a family history of kidney stones, gout, high blood pressure or bed rest can place individuals at higher risk.

Unfortunately, the signs and symptoms of a kidney stone can be similar to the general aches and pains during pregnancy. “Acute pain over the flank area with or without pain and discomfort in the pelvic or lower abdomen are common signs/symptoms of kidney stones during pregnancy,” explains Dr. Valle. Because it can be so difficult to determine if localized pain is pregnancy-related or something else, Dr. Valle cautions that it’s always important for a pregnant woman to head into her doctor’s office to get it checked out. “It is important for expectant moms to see a physician or go to the hospital if they are experiencing any type of back pain or pelvic pain,” she says.

Kidney stones may be a bit of a laughing matter to men talking about their version of having a baby, but to women who are actually having a baby, it’s no joke — and can even be deadly. “The presence of kidney stones can increase the risk of a kidney infection and thus maternal sepsis,” Dr. Valle explains. “If this occurs, the fetal complications include an increased risk for preterm contractions and delivery. Sepsis, if left untreated, can lead to death.”

Luckily, even for how dangerous they can be, diagnosing and treating kidney stones during pregnancy is actually relatively simple. While kidney stones in nonpregnant women are normally diagnosed with a CT scan, during pregnancy, a regular pelvic ultrasound will be used to pick up those stones and avoid any radiation to the fetus. “An ultrasound is acceptable but it is less sensitive in detecting a stone,” Dr. Valle says.

Treatment includes a lot of watching and waiting, so, hey, in a way maybe it’s just prepping you for that big labor day that will be coming soon enough, right? “Treatment is generally expectant management since approximately 80 percent of stones pass spontaneously,” explains Dr. Valle. “This generally involves fluids and pain relief.” She also notes that a consult with a urologist might be ordered if a woman is unable to pass the stone on her own and that the kidney stones be removed via minimally invasive techniques.

So remember pregnant ladies — drink that water up and when in doubt, get that pain checked out.

More on pregnancy

The scary condition that can cause miscarriage in healthy pregnancies
How far apart do you space pregnancies?
Pregnancy myths debunked

Review
Stones in pregnancy and pediatrics

Urinary stone disease is a highly prevalent condition affecting approximately 10% of the population, and has increased in incidence significantly over the past 20 years. Along with this, the rate of stone disease among women and children is also on the rise. The management of stone disease in specific populations, such as in children and during pregnancy can present unique challenges to the urologist. In both populations, a multi-disciplinary approach is strongly recommended given the complexities of the patients. Prompt and accurate diagnosis requires a high degree of suspicion and judicious use of diagnostic imaging given the higher risks of radiation exposure. In general, management proceeds from conservative to more invasive approaches and must be individualized to the patient with careful consideration of the potential adverse effects. However, innovations in endourologic equipment and techniques have allowed for the wider application of surgical stone treatment in these patients, and significant advancement in the field. This review covers the history and current advances in the diagnosis and management of stone disease in pregnant and pediatric populations. It is paramount for the urologist to understand the complexities of properly managing stones in these patients in order to maximize treatment efficacy, while minimizing complications and morbidity.

About the author

Leave a Reply

Your email address will not be published. Required fields are marked *