Tara Bauer from Pompano Beach, Fla., was well into her pregnancy when she discovered blood in her urine. “I got scared,” she says. “I didn’t know where the blood was coming from.”
She immediately contacted her doctor. The checkup gave no signs of bleeding from the vagina, so Bauer knew the baby was safe. However, her urine sample was acidic, which is usually a sign of a bladder infection. Bauer was given antibiotics, and having dealt with bladder infections before pregnancy, she was familiar with the symptoms (blood in the urine sometimes being one such symptom) and the treatment. However, the symptoms did not improve with the medications, as they should have. Her medications were changed and she was sent home.
Although a kidney stone is not a risk to the fetus directly, it can pose problems for the mother.
“Until that point, I was pain free, but by the time I got home from that appointment, I was in a lot of pain,” says Bauer. She turned around and went back to the hospital where the doctor now determined Bauer had kidney stones, of which she had no prior history. Luckily, the stones passed through her system quickly and she had no reoccurrence of them.
Kidney Stones and Pregnancy
Bauer’s bout with kidney stones while pregnant is not uncommon. Although pregnant women are no more likely to develop kidney stones than non-pregnant women, they are more likely to suffer with them while pregnant. The stones have likely been in the body before pregnancy but were dormant. They are diagnosed more often in pregnant women because they cause discomforts and concerns non-pregnant women might otherwise ignore.
Although a kidney stone is not a risk to the fetus directly, it can pose problems for the mother. It is important for doctors to diagnose where in the urinary tract the stones are. If the stones are in the kidney, they usually pose no problem, but as they move into the urinary tract, they can begin to cause complications.
Unfortunately, diagnosing kidney stones in a pregnant woman can be difficult. “We’re limited to what we can do,” says Dr. Andrew Portis, medical director of the HealthEast Kidney Stone Institute at St. Joseph’s Hospital in St. Paul, Minn. Dr. Portis says normally a CAT scan is used to determine whether or not the patient has kidney stones, but, except in emergency situations, pregnant women should avoid contact with radiation. Instead of a CAT scan, doctors will use an ultrasound, which is not as reliable. “Just because you can’t see a stone doesn’t necessarily mean they aren’t there,” he says. It isn’t always easy to judge by the symptoms alone, either, because most of the symptoms occurring from kidney stones (pain and discomfort) are also a natural part of pregnancy.
Kidney Stone Concerns
There are three main reasons why a woman should know she has a kidney stone and why it should be treated: pain, the chance of a preterm birth and the risk of kidney infection.
The kidney infection is the most serious of these issues. “If the kidney is not draining due to the stone, it can cause an infection, including a change of blood pressure that can be a risk for the fetus because the body begins to care for the mother first,” says Dr. Portis. Having a kidney infection during pregnancy also can lead the fetus to be born prematurely. So it is especially important for a pregnant woman to be treated for the kidney stones whenever possible.
However, a pregnant woman must be treated differently than non-pregnant women. In an ordinary case of kidney stones, doctors would use a treatment called lithotripsy, which is a non-surgical treatment that sends extracorporeal shock waves into the body. But this procedure is not possible for pregnant women for two reasons. First, doctors would prefer to avoid using anesthesia for a pregnant woman whenever possible, and second, doctors are unsure what effect the shock waves have on a fetus.
Instead, pregnant women are usually given a urethral stent to aid in passing the kidney stone. “The stent is a tube inserted from the bladder to the kidney,” explains Jonathan Masel, a urologist based in Hollywood, Fla. “The stent allows the urine to get past the stone, relieving the blockage and relieving the pain.” Because stents gather a lot of calcium, they need to be changed every six to eight weeks. If the pregnant woman is near the end of her term, a stent is probably the best way to go because it will not likely need to be replaced.
Another option is to use a nephroscopic tube, which is inserted into the back through a small incision. Attached to the tube is a small, external bag for drainage. It can be awkward to maneuver with the bag on the back, but it is also less invasive, especially if the kidney stones must be monitored for a long period of time.
Masel says between 60 to 80 percent of pregnant women will pass the kidney stones on their own. If it doesn’t happen during the pregnancy, she can pursue a surgical procedure after the baby is born.
Kidney Stone Prevention
Preventing kidney stones is a topic of ongoing research. What doctors do know is too much calcium does not cause kidney stones, so women should not deprive themselves of the calcium needed for pregnancy. Drinking plenty of water keeps the system well flushed and may help prevent the formation of stones.
Staying healthy is always important, and is especially so for pregnant women. Doctors would prefer not to treat women for kidney stones during pregnancy if at all possible. If a woman has a history of kidney stones, she should have X-rays done before she begins trying to get pregnant, and if stones are found, she and her doctor should discuss removing them before she becomes pregnant. Any woman who is concerned she could be at risk for kidney stones (for instance, someone who is susceptible to bladder infections) should talk to her doctor about being checked for stones.
“A pre-emptive strike is the best treatment option of all,” says Dr. Portis