Although women with renal failure now routinely carry and deliver healthy children after receiving a kidney transplant, pregnant women with a renal allograft are at risk of numerous complications including hypertension, preeclampsia, infection, and acute or chronic graft dysfunction. They also experience the effects of immunosuppressant drugs and are at increased risk of cesarean delivery. The fetus as well is at risk—of growth restriction, anomalies, and preterm delivery.
This case–control study of 53 pregnancies in 42 women with a renal transplant, managed at a single center in the years 1984–2003, compared 23 preterm deliveries at less than 35 weeks’ gestation with 30 term deliveries. The mean maternal age at the time of gestation was 31 weeks, and the interval from renal transplantation to pregnancy averaged 4.6 years. The commonest cause of renal failure, present in 32 patients, was chronic glomerulonephritis. More than three-fourths of women were taking maintenance doses of cyclosporin-based immunosuppressive drugs.
At the time of conception, hypertension complicated 21%, and proteinuria 6% of pregnancies. The serum creatinine exceeded 1.5 mg/dL before delivery in 38% of cases but only one case had a value exceeding 2 mg/dL. The incidence of preterm delivery was 43%. Cases with and those without preterm delivery did not differ with regard to maternal age, parity, or the state of the renal allograft. The commonest reasons for inducing labor were preeclampsia and deteriorating renal function. In 58.5% of cases the birth weight was less than 2500 g. The incidence of small-for-gestational age infants was 11%. Logistic regression analysis identified chronic hypertension before pregnancy, and proteinuria and a serum creatinine of 1.5 mg/dL or more before delivery as being significantly associated with an increased risk of preterm delivery. There was a single graft loss occurring 9 months after delivery, and seven other losses took place 3 to 11 years after delivery. There were no maternal or perinatal deaths during the study. Eight infants required artificial ventilation and two had periventricular leukomalacia. Only one fetal anomaly was encountered.