Characterization of pubertal development of girls in rural Bangladesh

Abstract

This study aimed to describe the timing and patterns of pubertal maturation of girls living in rural Bangladesh. Starting in September 2015, a total of 15,320 girls from a birth cohort, aged 9 to 15 years at initial encounter, were visited twice at about a one year interval, typically in their birth month. Participants were asked to self-report extent of pubertal maturation, including breast development, pubic hair growth and age at menarche, if applicable. Pubertal stage (abbreviated as B2 and B3-4 for breast development and PH2 and PH3-4 for pubic hair growth) was assigned. Data from both visits were pooled, yielding a total of 29,377 age-related observations per pubertal characteristic. Probit regression models were used to estimate distributions of age at which each stage of pubertal development was attained. Before age 8, <3% of the study population initiated pubertal maturation as indicated by onset of breast development (B2). The median (95% confidence interval) age of B2 and B3-4 was 11.02 (11.00-11.04) and 12.82 (12.80-12.83) years, respectively; and 12.93 (12.91-12.94) and 14.29 (14.27-14.31) years for the onset (PH2) and advanced stage (PH3-4) of pubic hair growth, respectively. Median age at menarche was 13.17 (13.15-13.19) years, with 2.15 years of timespan from B2 to menarche. Girls in rural Bangladesh progressed through puberty following a well-documented sequence of sexual maturation stages. The age at which each pubertal milestone took place was somewhat later, but the tempo from breast development to menarche was comparable to that observed elsewhere. Our findings present a current norm of pubertal maturation in a typical, rural adolescent population in South Asia, which could help inform future studies and interventions to preserve or improve early adolescent health and development.

Fig 1. Flow diagram of the study participants.

Fig 2. Prevalence of pubertal maturational stages by age at assessment of adolescent girls in rural Bangladesh.

A, Percent attainment of breast development stages B2+ and, B, B3-4. C, Percent attainment of pubic hair growth stages PH2+ and, D, PH3-4. E, Prevalence of menarche. All ages are centered on birth dates ± 6 months.

Fig 3. Cumulative frequency curves for pubertal development of adolescent girls in rural Bangladesh.

Abbreviations: B2, stage 2 for breast development; B3-4, stage 3–4 for breast development; PH2, stage 2 for pubic hair growth; PH3-4, stage 3–4 for pubic hair growth. Patterns represent composite of two assessments ~1 year apart. All ages are centered on birth dates ± 6 months.