Adolescent Pregnancy and Attained Height among Black South African Girls: Matched-Pair Prospective Study

Importance: The impact of adolescent pregnancy on offspring birth outcomes has been widely studied, but less is known about its impact on the growth of the young mother herself. Objective: To determine the association between adolescent pregnancy and attained height. Design: Prospective birth cohort study. Setting: Cohort members followed from birth to age 20 y in Soweto, South Africa. Participant: From among 840 Black females with sufficient data, we identified 54 matched pairs, in which a girl who became pregnant before the age of 17 years was matched with a girl who did not have a pregnancy by age 20 y. Pairs were matched on age at menarche and height-for-age z scores in the year before the case became pregnant (mean 15.0 y). Main Outcome Measures: The two groups were compared with respect to attained height, measured at mean age 18.5 y. Results: Mean age at conception was 15.9 years (range: 13.7 to 16.9 y). Mean height at matching was 159.4 cm in the adolescent pregnancy group and 159.3 cm in the comparison group (p = 0.3). Mean attained height was 160.4 cm in the adolescent pregnancy group and 160.3 cm in the comparison group (p = 0.7). Conclusions: Among Black females in Soweto, South Africa, adolescent pregnancy was not associated with attained height.