Aggression, physical activity levels and sex role identity in teenagers exposed in utero to MPA.

Sex-dimorphic traits and behavior were measured in a 17-year old prospective study of 74 teenager boys and 98 girls who had been exposed to medroxyprogesterone acetate in utero compared with 459 boys and 546 girls not exposed. Bem Sex Role Identity scores were identical in exposed and non-exposed teenagers of each sex. There were no significant differences between MPA-exposed and non-exposed males or females on the Buss-Durkee overall aggression scale and on its assaultiveness subscale. Mothers of exposed males more often reported that teachers had complained that their offspring were naughty in school. No such difference was reported for females, nor for other school behaviors of dominance/aggression, activity, shyness and quietness. Exposed and non-exposed children were similar in the number of accidents experienced in childhood, as reported by their mothers, and in participation in competitive sports. These findings fail to support hypotheses posed by earlier researchers that exposure in utero to medroxyprogesterone acetate might alter sex-dimorphic behavior or traits in later life.