Some women with inherited autosomal dominant polycystic kidney disease (ADPKD) might understandably be hesitant to try to have a family. When clusters of fluid-filled cysts form on kidneys and surrounding tissues, the kidneys enlarge and their function can be reduced, often progressing to kidney failure. Pregnancy outcomes are heavily weighted by the mother's level of kidney function and how well her blood pressure is controlled.
But hesitancy about what's usually called simply "PKD" wasn't a major factor for 40-year-old Cari Maxwell of Manheim, Pennsylvania, a director of operations for a technology company and proud mother of three girls, ages 19, 16, and 6. In an interview with HealthCentral, Cari says she approached the possibility of having children with PKD calmly, rationally, and optimistically.
Cari had learned about her diagnosis at age 18. Her father carried the gene, and she watched her mother help him with hemodialysis in their home until he underwent a kidney transplant in 1987. He died of a stroke in October 2018 at 74.
Managing PKD and blood pressure
Two major categories of blood pressure drugs often used as first-line agents for PKD patients are unsafe during pregnancy because they can potentially negatively affect the fetus: angiotensin-converting enzyme inhibitors (ACE inhibitors) that include benazepril and lisinopril, and angiotensin receptor blockers (ARBs) such as losartan and telmisartan.
Ensuring pregnant women with PKD control their blood pressure and have safe pregnancies and deliveries is often a delicate balancing act.
Cari had never taken blood pressure medication until after she'd had her first two children. She then took the calcium channel blocker Nifedipine ER prior to conceiving her third child, and then was advised to stop that due to potential risks. She was prescribed the beta blocker labatalol for use during that pregnancy.
"It was the best pregnancy of the three," she says. "I felt great."
When her third child was 3 months old, the medication JYNARQUE, or tolvaptan, had started its first trial to treat PKD. She was invited to participate, "but I wasn't willing to cut short nine months of nursing, since the medication isn't recommended during that time," Cari says. She did start a lisinopril regimen following her last pregnancy.
Tolvaptan is designed to prevent PKD cysts from growing or to at least slow their growth. She has been in the tolvaptan trial group since January 2016.
"It is helping me. It does, however, make me go to the bathroom a lot, and I have to drink a minimum of 3 liters of water daily. I still take lisinopril and have lowered it to 20 mg daily."
She understands that the longer she's on tolvaptan, the more benefits she'll have. "I’m getting out ahead of this disease, and I have a lot of hope," Cari says.
PKD risks during pregnancy
Cari is a member of the National Kidney Foundation's Kidney Advocacy Committee, and she champions early detection. The foundation says that 80 percent of PKD pregnancy cases are problem-free, but the other 20 percent are not — if a woman has high blood pressure and reduced or impaired kidney function. This can accelerate to preeclampsia, when the mother’s unusually high blood pressure can result in severe complications for her and her child.
"Patients with preeclampsia can have a systemic reaction with incredibly high blood pressure, seizures, development of heavy 'spilling" of protein into the kidneys — called proteinuria — liver problems including elevated liver enzymes, hematologic or blood problems such as low blood platelet count," says nephrologist and PKD expert Franz T. Winklhofer, M.D., at The University of Kansas Health System. He spoke to HealthCentral in a telephone interview.
A small 2016 study in The Journal of Maternal-Fetal & Neonatal Medicine found fetal complications between PKD and control groups were the same, with slightly more fetal distress in the ADPKD group. Preeclampsia in patients with simple cysts (2 percent) was similar to that of the general population, but pregnant ADPKD patients did have higher risks for hypertension, proteinuria, edema, urinary tract infection, renal dysfunction, and preeclampsia during their pregnancies.
Monitoring PKD in pregnancy
In reality, many women in their 20s and 30s have children and also have undiagnosed PKD, says Dr. Winklhofer. "In the early stages, women, especially if they're not hypertensive, do just fine. And statistically, this group hasn't been studied systematically."
Most PKD patients aren't diagnosed until their 30s or 40s.
"Patients with PKD don't necessarily follow closely with me until they've developed some renal insufficiency," he says. "And that late in life, not as many try to conceive. But among patients in their 30s, approximately one-third may develop high blood pressure during pregnancy."
The medical literature generally recommends target blood pressure below 130/80 for PKD patients.
Sometimes patients will tell him that they'd had high blood pressure issues "since my first or second child," and the subject comes up anecdotally. Dr. Winklhofer says that the more pregnancies a woman has when she's diagnosed with PKD, the more likely it is she will become hypertensive.
As one might expect, pregnant women with PKD require careful monitoring.
"Most everybody with PKD in general should own a blood pressure cuff anyway," he says. He recommends at least a weekly check, if not more, in conjunction with team care that includes management by an OB-GYN, "who will see them more frequently than I because of the inherent risks of the pregnancy."
Experts and patients agree that if you become pregnant, you will want to do the usual things you do to be "whole-body" healthy, such as getting enough exercise and eating well — including reducing sodium. A current review in UpToDate advises that PKD patients intake no more than 2 grams (2,000 mg) of sodium per day, which will benefit blood pressure control.
Will your child inherit PKD?
Because of the 50 percent chance that a child can inherit PKD, some women wonder how aggressively they should pursue "finding out" whether a baby in utero already has the condition.
"Sometimes obstetricians will see cysts on a fetal ultrasound, and if they don't, that doesn't mean a child won't develop them later," Dr. Winklhofer says. "If a mother doesn't know she has cysts — and is still undiagnosed herself — sometimes a uterine ultrasound will 'accidentally' show cysts on her own kidneys."
Cari says they looked at the baby's kidneys during all three of her pregnancies.
"They were fine, but it's true that we don't know what the long-term prognosis could be," she says. "I was also offered a genetic test all three times, and declined. I believe that whatever happens, happens, and that improvements in medicine may change the future of what's to come for my children. Plus, we have access to great doctors."
Dr. Winklhofer also doesn't recommend screening minors with no symptoms, since there's no effective treatment, and knowledge of the condition could severely impact prospects of obtaining health or life insurance later.
Finally, he reiterates that managing pregnancy with PKD is a very personal journey, and he doesn't dissuade women from trying to conceive.
"I think risks are manageable," he says. "Advances in treatment really have changed the way we think about PKD and pregnancy, especially with tolvaptan, and especially if you get treated with it early enough."