P94. Preeclampsia in pregnancies with and without diabetes; the associations with placental weight. A population study of 655,842 pregnancies

Abstract

Introduction Women with diabetes are at increased risk of preeclampsia, and women with diabetes tend to deliver placentas and offspring that are large for gestational age. Therefore, it is reasonable to suggest that large placentas in preeclamptic pregnancies may be attributed to concomitant maternal diabetes. Objectives We studied whether the placental weight in preeclamptic pregnancies differs in women with and without diabetes. Methods Information on all singleton births from 1999 through 2010 (n = 655,842) were obtained from the Medical Birth Registry of Norway. We used z-scores of placental weight to adjust for differences in gestational age between deliveries, and compared the distribution of placental weight z-scores in tenths in preeclamptic pregnancies with and without diabetes, and in normotensive pregnancies with and without diabetes. Results When comparing z-scores, there was no difference in mean placental weight in pregnancies with diabetes with or without preeclampsia (ANOVA-test; p = 1.00). However, mean placental weight was significantly higher in pregnancies with diabetes as compared to pregnancies with preeclampsia only or in pregnancies with none of these conditions (ANOVA-test; p Among preeclamptic pregnancies, having a placental weight in the highest tenth of placental weight was nearly three times more frequent (28.8%) in pregnancies with diabetes compared to pregnancies without diabetes (9.8%). In the lowest tenth of placental weight, preeclamptic pregnancies with diabetes were underrepresented (7.5%), and preeclamptic pregnancies without diabetes were overrepresented (13.6%). Thus, among women with diabetes, more pregnancies with high as compared to low placental weight developed preeclampsia. Conclusion These results suggest that women with diabetes who develop preeclampsia have larger placentas than other women with preeclampsia. Thus, the placental involvement in preeclampsia may differ by diabetes status.