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 micromol/L] or blood urea nitrogen [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
After kidney transplantation Kidney Transplantation Kidney transplantation is the most common type of solid organ transplantation. (See also Overview of Transplantation.) The primary indication for kidney transplantation is End-stage renal failure... read more , full-term, uncomplicated pregnancy is often possible if women have all of the following:
A transplanted kidney that has been in place for > 2 years
Normal renal function
No episodes of rejection
Normal blood pressure (BP)
Treatment of renal insufficiency during pregnancy requires close consultation with a nephrologist. BP and weight are measured every 2 weeks; 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 weeks 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 a week. 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.
Women who have significant renal insufficiency before pregnancy usually cannot maintain a pregnancy to term.
In pregnant women with renal insufficiency, measure BP and weight every 2 weeks, and measure BUN and creatinine levels plus creatinine clearance often, as indicated by severity and progression of disease.
Consult closely with a nephrologist when treating renal insufficiency in a pregnant woman; delivery is usually required before term.
Advances in dialysis treatment have increased life expectancy for patients with end-stage renal disease, improved pregnancy outcomes, and increased fertility, but complication rates for these patients remain high.