Incidence rate of premature breast development and its causative factors among five-year-old girls in Shanghai municipality
GUO Youning, WU Minlun, SHEN Shuixian Shanghai Institute of Planned Parenthood Research, Shanghai 200032, P.R.China
Objective To investigate the prevalence of premature breast development in girls aged less than 5 years in the early 1990 s in Shanghai Municipality and its social and biomedical factors.Methods A follow up study with a cohort of couples who married for one year in the late 1980 s was carried out to the 6th year after their marriage to investigate their contraceptive intake, reproductive conditions, and health status of their babies . The breast development status of all of the girls born by these wives was examined at the last time of the follow up.Results The prevalence of premature breast development for this cohort of girls was 15.15 ‰ (52/3432) and 59.6 % of them (31/52)were detected at the last time of visiting. Only 5 cases recovered (23.8 %) among the 21 girls who had been detected prior to the last time of visiting. 87.2 % of the breast development was bilateral and 74.5 % of the halo enlarged were between 1.0～ 1.4 cm. About 16.2 % babies surveyed took the nourishing complements after birth. Fitting the Logistic regression model showed that taking the nutriment by the girls was the main factor in influencing the early breast development (OR= 4.38, 95 % confidence interval 2.41,7.96). Couples with a lower monthly income or who had never adopted any eugenic methods while conceiving would also be more prone to have girls with early enlarged breasts(OR=2.52, 95 % 1.26,5.02 for the former and OR=2.17,95 % 1.11,4.23 for the later).Conclusions The prevalence of premature breast development for this cohort of girls was 15.15 ‰(52/3432). Apart from the factor of nutriment intake early by the babies ,social economic condition and the general health condition of the mothers would also influence their girls'early breast development, which should be improved to protect the baby girls from premature breast development.