Hormonal considerations in early normal pregnancy and blighted ovum syndrome

The hormonal profiles of six pregnancies which terminated in miscarriage with the blighted ovum syndrome have been studied and compared with those of a group of patients similarly studied who had clinically normal pregnancies terminating in live birth at term. The serum chorionic gonadotropin (HCG) values were below normal or at the lowest limit of normal in five of six patients. Three patients had progesterone values within 1 SD of the normal, with normal serum estradiol values. It was concluded that the hormonal profile of early pregnancy is characterized by rising serum HCG and estradiol levels and a declining serum progesterone level from the 5th to the 8th week. The theoretical explanation for the dichotomy seems to be that the fetal adrenal anlagen, even at this early embryonic stage, can produce steroid precursors which are aromatized to estradiol. The production of progesterone, however, does not seem to be possible. Abnormal serum estradiol levels strongly suggest the absence of fetal development and a blighted ovum. However, no single hormonal level will distinguish between blighted ovum and potentially salvagable threatened abortion.