Two groups of boys exposed prenatally to exogenously administered estrogen and progesterone were studied on several parameters of psychosexual development. Subjects were twenty 6-year-olds and twenty 16-year-olds whose diabetic mothers received these hormones to prevent pregnancy complication. Hormone-exposed boys were compared with same-aged boys whose mothers had not received exogenous hormones and matched for age and socioeconomic class.
Sixteen-year-olds exposed to estrogen and progesterone were rated lower on several variables related to general "masculinity," assertiveness and athletic ability. Six-year-olds exposed to estrogen and progesterone were rated lower on aggressivity and athletic ability. There were two cases of hypospadias among experimental subjects. While it was not possible to rule out influences other than hormonal which may have influenced results, data suggest that prenatal sex hormone levels may influence some aspects of postnatal psychosexual development in boys.
Yalom ID, Green R, Fisk N. Prenatal Exposure to Female HormonesEffect on Psychosexual Development in Boys. Arch Gen Psychiatry. 1973;28(4):554-561. doi:10.1001/archpsyc.1973.01750340080013