Perinatal factors in the development of gender-related play behavior: sex hormones versus pregnancy complications.

This report addresses the question of biological factors that may contribute to the development of gender-typical and gender-atypical play behavior. In lower mammals, sex differences in juvenile behavior are to a considerable extent determined by organizational effects of prenatal or perinatal androgenic hormones. Birke and Sadler (1983) showed that not only perinatal androgens but also progestogens such as medroxyprogesterone acetate (MPA) affect (in this case: demasculinize) the play behavior of both sexes in the rat. Here, we report on a study of sex-dimorphic play behavior of children born from pregnancies that were treated with various sex hormones. The Child Game Participation Questionnaire (Bates and Bentler 1973) was administered to 13 boys and 15 girls prenatally exposed to MPA, 22 boys and 15 girls exposed to a variety of synthetic progestogens or estrogens singly or in combination, and to pair-matched control subjects, all between 8 and 14 years old. Pregnancy complications were assessed by two scores, 1) "Pregnancy Complications Summary Score (excluding bleeding)," 2) "Vaginal Bleeding During Pregnancy." The results of paired t-tests showed a number of hypomasculinization effects for the hormone-exposed groups. Controlling for the effects of pregnancy complications and age at study by exploratory hierarchical multiple regression analysis indicated that these variables did not account for the hormone-exposure effects. Our results provide further evidence that prenatal hormones influence the sex-dimorphic play behavior of human children in the same direction as that of other mammals.