CHICAGO — Tight blood pressure control is crucial in caring for pregnant women with lupus nephropathy, but medication management must factor in potential fetal risks, Dr. Phyllis August said at a meeting on clinical nephrology sponsored by the National Kidney Foundation.
In reviewing the management strategies for pregnant women with preexisting lupus nephropathy and diabetic nephropathy, Dr. August noted that the most effective management begins even before conception. Even though preconception counseling can improve outcomes, physicians typically care for gravid women who already have significant disease.
“Overall, the outcome in pregnancy is related to the baseline blood pressure and level of renal function at the beginning of pregnancy,” said Dr. August, professor of medicine at the Weil Medical College of Cornell University, New York.
ACE inhibitors and angiotensin-receptor blockers (ARBs) are vital in the treatment of lupus or diabetic nephropathy in women who are trying to conceive, but these agents are potentially quite harmful to the developing fetus, she noted.
Switching to a safer agent (such as methyldopa or labetalol) as soon as a patient misses her menstrual period to get the greatest benefit. “The overwhelming evidence for the adverse effects of ACE inhibitors and ARBs relates to second- and third- trimester exposure,” she said.
Dr. August also recommended performing a cardiac evaluation before conception in women with long-standing lupus or type 1 diabetes. “Significant renal disease is associated with preeclampsia and renal complications,” she noted. Chronic kidney disease also increases the risk of intrauterine growth retardation and preterm birth.
Lupus nephropathy can be quite challenging for both patients and physicians, Dr. August noted. “There is a poor outcome when the disease is active at conception,” she said.
A high percentage of patients—as many as 50%–80%—will experience a disease flare during pregnancy if they have active disease at conception. On the other hand, only 10%–40% of women who are in remission at conception will have a flare.
Physicians may safely use azathioprine to treat pregnant women with lupus nephritis. Dr. August also advocated delivery during the third trimester in gravid women whose lupus nephritis is deteriorating quickly.
The mother's condition often improves quickly after delivery.
Women with lupus and antiphospholipid antibody syndrome are also at higher risk of fetal loss, arterial and venous thrombosis, renal vasculitis, and preeclampsia. Women with this syndrome may benefit from taking low-molecular-weight heparin, with or without aspirin.
Although the outlook has improved for women with certain types of chronic kidney disease who wish to bear children, the chance of a good pregnancy outcome in women with end-stage renal disease on dialysis remains poor. Women who become pregnant while on dialysis have a high incidence of adverse outcomes such as second-trimester pregnancy loss, prematurity, and congenital abnormalities. These women “should never be encouraged” to get pregnant, Dr. August said.