Trends in Fetal and Infant Survival Following Preeclampsia

Context: Management of preeclampsia often culminates in induced delivery of a very preterm infant. While early termination protects the fetus from an intrauterine death, the newborn then faces increased risks associated with preterm delivery. This practice has increased in recent decades, but its net effect on fetal and infant survival has not been assessed.

Objective: To assess the effect on fetal and infant survival of increased rates of early delivery of preeclamptic pregnancies.

Design, Setting, And Participants: Population-based observational longitudinal study using registry data from 804 448 singleton first-born infants with Norwegian-born mothers and registered in the Medical Birth Registry of Norway between 1967 and 2003.

Main Outcome Measures: Odds ratio (OR) of fetal and early childhood death in relation to preeclampsia.

Results: Among preeclamptic pregnancies, inductions before 37 weeks increased from 8% in 1967-1978 to nearly 20% in 1991-2003. During this period, the adjusted OR for stillbirth decreased from 4.2 (95% confidence interval [CI], 3.8-4.7) to 1.3 (95% CI, 1.1-1.7) for preeclamptic compared with nonpreeclamptic pregnancies. During the same period, the OR for neonatal death after preeclamptic pregnancy remained relatively stable (1.7 in 1967-1978 vs 2.0 in 1991-2003). Later infant and childhood mortality also showed little change.

Conclusions: Fetal survival in preeclamptic pregnancies has vastly improved over the past 35 years in Norway, presumably because of more aggressive clinical management. However, the relative risk of neonatal death following a preeclamptic pregnancy has not changed over time.