Olga Basso, PhD, of the National Institute of Environmental Health Sciences, Research Triangle Park, N.C., and colleagues examined changes over time in perinatal and early childhood survival in relation to preeclampsia in Norway. The study included data from 804,448 first-born infants with Norwegian-born mothers and registered in the Medical Birth Registry of Norway between 1967 and 2003, including 770,613 pregnancies without preeclampsia and 33,835 pregnancies with preeclampsia.
The researchers found that among preeclamptic pregnancies, inductions before 37 weeks (of gestation) increased from 8 percent in 1967-1978 to nearly 20 percent in 1991-2003. In 1967-1978, more than 25 percent of all infants born before 34 completed weeks died in the neonatal period, as opposed to 5 percent in 1991-2003.
"Preeclampsia was an important cause of fetal death in Norway during the late 1960s and throughout the 1970s, but its impact has waned. While risk of stillbirth was 4.2 times higher with preeclampsia, it is now only 1.3 times higher. Preeclampsia still carries a 2-fold increased risk of neonatal death, which has changed little over time. This stability in neonatal risk is remarkable, considering the increasing number of very preterm deliveries in recent years resulting from aggressive obstetric management of preeclampsia. Modern medical management of preeclampsia appears to have been effective in preventing fetal death without causing an increase in infant or maternal death," the authors conclude.