Decreased gestational sac volumes in pregnancies induced by human menopausal gonadotropin.

Mean gestational sac volumes of 9 singleton pregnancies induced by human menopausal gonadotropin (hMG) measured by ultrasound were compared with mean gestational sac volumes obtained from 37 normal singleton pregnancies, 6 to 8 weeks from the last menstrual period. HMG-induced gestational sacs were smaller at 6 and 7 weeks of gestation, compared with normal pregnancies. Despite the initial lag in gestational sac volume, hMG-induced pregnancies subsequently demonstrated appropriate fetal growth as measured by crown-rump length measurements between 8 and 12 weeks. These pregnancies also demonstrated normal fetal growth patterns in the second and third trimesters of pregnancy, as assessed by clinical evaluation and ultrasound. These preliminary data suggest that early growth development in hMG-induced pregnancies may be different from that in spontaneously occurring pregnancies.