HUMAN CHORIONIC-GONADOTROPIN LEVELS BETWEEN 15 AND 17 WEEKS IN WOMEN WHO SUBSEQUENTLY DEVELOP PREECLAMPSIA

Objectives: Preeclampsia (PET) is associated with abnormal cytotrophob last invasion. Serum levels of human chorionic gonadotrophin (hCG) ref lect both the volume and maturity of trophoblast. Our aim was to inves tigate whether early midtrimester levels of maternal serum hCG in wome n subsequently developing preeclampsia differ from those of the normal pregnant population. Method: A retrospective analysis of serum beta h CG concentrations measured, between 15 and 17 weeks, as part of antena tal serum screening for fetal Down's syndrome in women who subsequentl y developed PET. The beta hCG concentrations were expressed as multipl es of the median value for the local population adjusted for gestation al age. The women had otherwise uncomplicated singleton pregnancies an d delivered chromosomally normal fetuses. A sample from the original p opulation was taken as a control group (n = 625). Results: Forty-eight women who developed PET were identified. Their second trimester beta hCG was significantly elevated (P = 0.0008) with a median of 1.30 MOM when compared to that of the control group MOM. The mean gestational a ge at delivery was 35 weeks, 4 days and the population's mean birthwei ght was on the 40th centile. There was no difference in the ol-fetopro tein levels. Conclusions: This study shows that women who subsequently develop preeclampsia tend to have elevated serum hCG levels early in the second trimester compared to the population as a whole. This may b e associated with abnormal early placental development, such as hyperp lacentosis or delayed placental maturation.