Preeclampsia Not Linked to Prior Miscarriage, Abortion.

Only term pregnancies offer real protection.

ST. JOHN'S, NFLD. -- In the hunt for factors that place women at greater risk of preeclampsia, researchers have crossed at least one suspect off the list: a history of miscarriage or abortion.

Until now, it hasn't been clear how to counsel women with a history of abortion or miscarriage regarding their risks of preeclampsia in subsequent pregnancies. There were so few studies in the literature and the studies that were available involved so few patients that "we couldn't answer the question" adequately Dr. Nestor N. Demianczuk said in an interview.

In a study presented at the annual meeting of the Society of Obstetricians and Gynecologists of Canada, Dr, Demianczuk of the University of Alberta in Edmonton and his colleagues analyzed more than 140,000 pregnancies which resulted in deliveries at 49 hospitals in northern and central Alberta between 1993 and 1999.

They considered nearly 200 patient factors that could possibly play a role in the development of preeclampsia, including abortion, medical history, smoking, and medication and alcohol use during pregnancy.

They found that among 51,430 nulliparous women--a population that is believed to be at highest risk for preeclampsia--the rate of the disorder among those with a history of abortion, either spontaneous or elective, was 2.6%. That rate was not statistically different from the 2.9% rate among women without a history of abortion, The risk of preeclampsia among women who had never been pregnant was 2.9%.

Multiparous women with a history of giving birth to term newborns had the lowest incidence of preeclampsia (0.9%).