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 renal transplantation, full-term, uncomplicated pregnancy is often possible if women have all of the following:

• A transplanted kidney that has been in place for > 2 yr
• Normal renal function
• No episodes of rejection
• Normal BP

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 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. Which antenatal tests are done depends on the stage of pregnancy. Nonstress tests are usually done first, followed by an oxytocin challenge test or a biophysical profile if required. If results 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.

Last full review/revision December 2008 by Sean C. Blackwell, MD