Sibling composition and household room sharing are associated with menarcheal status among rural Bengalee girls of West Bengal, India.

Menarche, the first menstruation, is one of the most important events in a woman's reproductive life. The timing of menarche varies across populations and depends upon social interaction and family environment. It is also associated with several biological as well as social factors. The objective of this study was to explore the relationship between sibling composition and age at menarche (AAM) and to assess the association between the pattern of room sharing with family members of different sexes and menarcheal occurrence among rural Bengalee girls from West Bengal, India. The total sample comprised 577 Bengalee girls, 6-17 years of age, from various schools and madrasas in two blocks of the Nadia District of West Bengal State in India. The effects of room sharing on the occurrence of menarche, and of sibling composition on the menarcheal age, were assessed by analyses of covariance. The room-sharing pattern had a significant effect on menarcheal status (yes÷no): a significantly higher percentage of girls who shared a room with the mother and÷or sisters were postmenarcheal compared with those who shared a room with male family members. AAM did not differ significantly between girls having brothers or sisters. However, sibling order had a significant impact on AAM. Girls who had a younger sibling only (brother or sister) had a higher mean AAM, and girls who had both younger brothers and younger sisters had significantly higher mean AAM, than did the girls who had no younger sibling (singletons or having only elder siblings). There was no difference in AAM between the girls who had younger sister(s) and those who had younger brother(s). These differences were also independent of body mass index. In conclusion, the room sharing characteristics and the sibling sex composition, particularly their order, had significant effect on menarche in adolescent rural Bengalee girls.