NEW YORK (Reuters Health) – The risk of preeclampsia in a second or third pregnancy is directly related to the time that elapses since the preceding delivery, according to a report in the January 3rd issue of the New England Journal of Medicine..
Dr. Rolv Skjaerven, of the University of Bergen in Norway, and colleagues analyzed data from the Medical Birth Registry of Norway for 1967 to 1998. Included were more than 500,000 sets of first and second singleton deliveries, and more than 200,000 sets of first, second, and third singleton deliveries.
The risk of preeclampsia during a second pregnancy increased as the time since the first delivery increased. After adjusting for maternal age, the estimated odds ratio for preeclampsia was 1.13 per year. When interbirth intervals approached 10 years or more, a multiparous woman was at as much risk of preeclampsia as a nulliparous woman.
According to the authors, one interpretation of the data is that a change of partner, more common among women with longer interbirth intervals, could cause the increased risk of preeclampsia with time. However, "the effect of changing the partner was eliminated when the interbirth interval was taken into account," Dr. Skjaeven's team writes. Thus, there appears to be no increased risk of preeclampsia associated with a change of partner.