Reproductive capacity of the mentally retarded.

Ninety-seven mentally retarded females were studied to evaluate parameters of growth and development of secondary sex characteristics and the incidence of ovulation. These patients were selected on the basis of age and etiological classification. Patients were classified as Down's syndrome, brain damaged, or undifferentiated. The following parameters of growth and development were studied: anthropometric, bone age, and sexual maturation. Sexual maturation studies consisted of breast development, pubic hair, axillary hair, menarche, menstrual pattern, and ovulatory patterns. The following observations were made from this study: 1. Physical growth and secondary sexual development were retarded in all parameters. 2. The undifferentiated and brain damaged groups showed almost identical patterns of growth and development of secondary sexual characteristics. 3. The Down's syndrome group was the most retarded in physical growth and in secondary sexual development. 4. Skeletal age was a better guide than chronological age or height and body weight to the prediction of development of secondary sex characteristics and age at onset of menarche. 5. In 26 mentally retarded females who had achieved menarche the incidence of ovulation was approximately 60 percent.