Dr. Marjorie Greenfield
Specializing in pregnancy and birth.
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 Ask Dr. Greenfield
Kidney Stones and Pregnancy | | | QUESTION | | | Dear Dr. Greenfield,
I developed kidney stones during the fifth month of my last pregnancy. I had never had any before nor have I had any since, and my doctors all agreed it was pregnancy related. Somehow my body did not use the calcium appropriately or something. I was given a 50 percent chance of a reoccurrence in another pregnancy. It was extremely painful and could not be taken care of fully until a month after my son was born. I was on Vicodin, on bed rest, and at the hospital for preterm labor or to have stents put in to drain the kidney more that I'd like to recall. After a failed adoption I decided to get pregnant again and am very worried about this happening again! In the meantime I am drinking tons of water and taking nothing with added calcium.— DueinSept. in Arizona | | | ANSWER |
February 6, 2002 | | | Dear DueinSept,
I can understand being worried about getting pregnant after such an awful experience. I can't really say, though, that your kidney stones were pregnancy related, despite that being the opinion of your doctors. In general, stones can occur at any time. About 1 percent of women will get a kidney stone at some point (the risk is higher for men), and about 50 percent of people with a stone will have a recurrence within 10 years. I tried to research the relationship between stones and pregnancy for you, and there doesn't seem to be any connection. We used to think that women who took calcium in pregnancy increased their risk, but that, too, isn't true. It may be that the fluid intake needs are greater in pregnancy, and mild dehydration may have played a role in your miserable experience.
The best prevention of recurrence of unexplained kidney stones is to drink water. A lot of water--enough water to make 2.5 to 3 liters of urine a day. To see if you are drinking enough, you can measure your urine output over a 24-hour period by collecting it and transferring it into large soft drink bottles. You should fill up one and a half 2-liter bottles. You may find that you have to work very hard to drink enough fluids to get this kind of urine output, but that's the best prevention known to medical science.
Interestingly, it turns out that calcium intake doesn't predispose to recurrent kidney stones, and actually people with the highest intake of calcium are least likely to make stones. Since most women don't get enough calcium, particularly during pregnancy, you may want to rethink your plans to avoid calcium.
The one clear dietary risk factor for stone formation is intake of grapefruit juice. It isn't known why grapefruit juice is a problem when orange juice isn't, but this has been shown in numerous studies. In addition, some experts believe that dietary oxalate, found in nuts, chocolate, dark-green leafy vegetables, rhubarb, beets and okra, and in concentrated tomato sauce and jams can increase the chance for another stone, but the final word isn't in yet. Since you probably want to do everything to try to prevent another kidney stone, avoidance of these foods is reasonable.
I hope that this information is helpful to you, and that your pregnancy goes well, despite your fears. A consultation with a urologist (specialized surgeon) a nephrologist (specialized internist) or a perinatologist (specialized obstetrician) may help get you the most up-to-date recommendations about kidney stone prevention for your individual situation. Take care, and good luck!— by Marjorie Greenfield, M.D. |
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