Menarche, menstruation, sexual relations and contraception of adolescent females with Down syndrome.

Fifteen female adolescents with Down syndrome (DS) and 33 female controls without this syndrome were surveyed on age of menarche, menstruation, sexual relations and contraception. All probands and controls were born between 1 January 1965 and 31 December 1970. The day of census was December 31, 1985. All probands and controls were living permanently in the Danish county of Aarhus on this day. Persons close to the DS patients (parents/foster-parents/permanent staff) were interviewed on the above-mentioned topics. All controls were interviewed themselves. The average age of menarche was 13.6 years for probands and 13.5 years for controls. The average duration of the bleeding was 5.5 days for probands and 5.4 days for controls. The average length of the cycle was 28.3 days for probands and 28.6 days for controls. Thirteen DS patients had not had sexual intercourse (no information was available for 2 probands). Twenty-four controls had and 9 had not had sexual intercourse. There is a significant difference between probands and controls concerning use of oral and other contraceptives.