Pregnancy often does not worsen renal disorders; it seems to exacerbate noninfectious renal disorders only when uncontrolled hypertension coexists. However, significant renal insufficiency (serum creatinine > 3 mg/dL [> 270 μmol/L] or BUN > 30 mg/dL [> 10.5 mmol urea/L]) before pregnancy usually prevents women from maintaining a pregnancy to term. Maternal renal insufficiency may cause fetal growth restriction and stillbirth.
After kidney transplantation, full-term, uncomplicated pregnancy is often possible if women have all of the following:
Treatment requires close consultation with a nephrologist. BP and weight are measured every 2 wk; BUN and creatinine levels plus creatinine clearance are measured often, at intervals dictated by severity and progression of disease. Furosemide is given only as needed to control BP or excessive edema; some women require other drugs to control BP. Women with severe renal insufficiency may require hospitalization after 28 wk gestation for bed rest, BP control, and close fetal monitoring. If results of antenatal testing remain normal and reassuring, the pregnancy continues.
Delivery is usually required before term because preeclampsia, fetal growth restriction, or uteroplacental insufficiency develop. Sometimes amniocentesis to check fetal lung maturity can help determine when delivery should be done; a lecithin/sphingomyelin ratio of > 2:1 or presence of phosphatidylglycerol indicates maturity. Cesarean delivery is very common, although vaginal delivery may be possible if the cervix is ripe and no impediments to vaginal delivery are evident.
End-stage renal disease:
Advances in dialysis treatment have increased life expectancy for patients with end-stage renal disease, improved pregnancy outcomes, and increased fertility. The survival rate for fetuses of pregnant women receiving hemodialysis has improved from 23% (in about 1980) to almost 90% currently. The reason is probably the substantial increase in hemodialysis dose used during pregnancy; now, high-flux, high-efficiency hemodialysis is typically done 6 times/wk. Dialysis can be adjusted based on laboratory, ultrasonographic, and clinical findings (eg, severe hypertension, nausea or vomiting, edema, excessive weight gain, persistent polyhydramnios). Although pregnancy outcomes have improved, complication rates for patients with end-stage renal disease remain high.
Last full review/revision June 2013 by Lara A. Friel, MD, PhD
Content last modified October 2013