TUESDAY, Sept. 19 (HealthDay News) -- The number of fetal and infant deaths caused by the serious pregnancy complication preeclampsia has dropped sharply since the 1960s, a new study reports.

The research, published in the Sept. 20 issue of the Journal of the American Medical Association, theorizes that earlier delivery of babies whose mothers have preeclampsia and better prenatal care for their mothers have contributed to the dramatic decline.

"Babies had more than a fourfold risk of dying in utero during the first period [of the study], 1967 to 1978. At the end of the study, 1991 to 2003, the risk of stillbirth was 1.3-fold higher in mothers with preeclampsia," said study author Olga Basso, a research fellow at the National Institute for Environmental Health Sciences, in Research Triangle Park, N.C.

Preeclampsia is a potentially fatal complication of pregnancy that affects up to 8 percent of all pregnancies, according to the Preeclampsia Foundation. It's most common in first pregnancies and is characterized by high blood pressure, water retention and protein in the urine. Sudden severe headaches, vision changes, swelling and weight gain indicate worsening preeclampsia.

The disorder often comes on quickly, and there's no good way to know for sure which women will develop the condition. However, researchers from the National Institute of Child Health and Human Development recently announced that they have had success detecting those at risk of preeclampsia earlier in pregnancy by testing for high blood levels of certain proteins. In the future, doctors may be able to use such a test to diagnose preeclampsia at an even earlier stage.

Unfortunately, there's currently no truly effective treatment for preeclampsia except delivery of the child. Often, however, a mother may not be far enough along in her pregnancy to safely deliver the baby. In this case, doctors try to control the mother's blood pressure and give her medications to help the fetus' lungs mature more quickly. Worldwide, preeclampsia is responsible for about 76,000 maternal and fetal deaths, according to the Preeclampsia Foundation.

Rates of preeclampsia have been on the rise for years, possibly due to the number of mothers putting off pregnancy until a later age and the use of assisted reproductive technologies, according to Dr. Abdulla Al-Khan, director of perinatal diagnostics and therapeutics, a division of maternal fetal medicine at Hackensack University Medical Center in New Jersey.

"Preeclampsia has become an epidemic the U.S.," he said.

Almost 800,000 pregnant women were included in the current study. All were Norwegian-born and pregnant for the first time. The data from these pregnancies was collected from 1967 through 2003. Nearly 34,000 of these women developed preeclampsia during their pregnancies.

Between 1967 and 1978, only 8 percent of the mothers had induction of birth -- either by induction of labor or by Caesarean section. From 1991 through 2003, that number jumped dramatically, to 20 percent.

During that same time, fetal death rates also dropped dramatically. The risk of having a stillbirth for a woman with preeclampsia was 4.2 times higher than for a woman without preeclampsia between 1967 and 1978. From 1991 to 2003, the risk of a stillbirth for a preeclamptic woman was 1.3 times higher than for a pregnant woman without the disorder.

Meanwhile, newborn death rates stayed mostly the same.

"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," the authors wrote.

Basso said earlier deliveries and medical management of the mothers throughout their pregnancies appeared to help bring the fetal and newborn death rates down.

Al-Kahn said he wasn't particularly surprised by the findings, and he said that he agrees that getting these babies delivered early is probably the biggest factor in the increased survival. Plus, he said, care for premature babies has advanced considerably in recent years.

"Especially in the U.S., we have stronger newborn intensive care and premature babies are doing much better," said Al-Khan.

He did, however, point out that this study's findings aren't necessarily applicable to the much more ethnically and socially diverse U.S. population.

More information

To learn more about preeclampsia, visit the Preeclampsia Foundation.