MATERNAL PLASMA-LEVELS OF HUMAN CHORIONIC-GONADOTROPIN, ESTRADIOL AND PROGESTERONE IN MULTIFETAL PREGNANCIES BEFORE AND AFTER FETAL REDUCTION

The aim of the study was to investigate the circulating levels of human chorionic gonadotrophin (hCG), oestradiol (OE(2)) and progesterone in multifetal pregnancies before and after embryo reduction. The levels of hCG, OE(2) and progesterone were measured in plasma samples obtained from two groups of pregnant women: (i) singleton (n=17), twin (n=15) and triplet (n=5) pregnancies achieved following superovulation; and (ii) multifetal pregnancies (three to ten embryos) undergoing fetal reduction to twin pregnancies (n=31). The median value for each analyte at each gestational age in twin pregnancies was defined and used to derive multiples of the median (MoMs) for each analyte in samples obtained from multifetal pregnancies before and after reduction. The levels of hCG, OE(2) and progesterone were significantly associated with the number of fetuses. Prior to reduction, the median MoMs for hCG, OE(2) and progesterone were 1.54, 0.99 and 1.11 respectively. After reduction to hiins the median MoMs decreased to 0.84 for hCG, 0.37 for progesterone and 0.51 for OE(2). These data suggest that (i) the circulating levels of hCG, OE(2) and progesterone increase with conceptus number; (ii) placental tissue does not remain active following fetal reduction; and (iii) the rate ofsteroid metabolism is increased in multiple pregnancy and remains elevated folloming fetal reduction.