Fetal growth retardation and second trimester maternal serum human chorionic gonadotrophin levels

Second trimester maternal serum human chorionic gonadotrophin (hCG) levels in women who remained normotensive but delivered an unexplained growth retarded infant were compared with those from a control group and a group of women who developed pre-eclampsia in a retrospective observational study. Our hypothesis was that the similar placental pathological changes shared by unexplained normotensive IUGR and pre-eclampsia would be reflected by elevated maternal serum hCG levels in the second trimester. Normotensive women delivering unexplained singleton growth retarded infants were identified (n=43) and their second trimester hCG levels, taken as part of antenatal screening for Down's syndrome, were obtained. These were compared with a control group of 625 women, and a group of 48 women who subsequently developed pre-eclampsia. There was no significant difference in the hCG levels expressed as multiples of the median (MOM) between the women who delivered growth retarded fetuses (median MOM 0.96) and the control group (median MOM 0.97). The levels of hCG in the women who subsequently developed pre-eclampsia were significantly higher (median MOM 1.3, P=0.008). There were no significant differences in AFP levels in the three groups; however, the trend was towards a higher level of AFP in the fetal growth retardation group. Maternal serum hCG in the second trimester does not appear to be elevated in normotensive women who later produce a growth retarded fetus, although human chorionic gonadotrophin levels are significantly higher in women who subsequently develop pre-eclampsia.