婴幼儿乳房发育的全国多中心研究初探

Multi-center study of premature thelarche and gynecomastia in Chinese infants and toddlers

目的初步了解中国婴幼儿乳房发育的发生率，同时探索其发生的高危因素，以及婴幼儿乳房发育对其体格生长、神经认知发育和运动发育的影响。方法采用多中心横断面研究，2011年10月至2012年3月选取来自中国8个省1510名0—48月龄足月、健康婴幼儿作为研究对象，并对其身长（高）、体重、乳房发育情况、神经发育水平进行测试，同时家长完成儿童个人及家庭社会环境问卷。结果研究发现乳房发育发生率为1．6％（23／1475），其中男童1．0％（8／780），女童2．2％（15／695），均发生于2岁以内的婴幼儿。控制了年龄、性别后，父亲受教育程度低（OR=3．632，95％CI=1．565～8．432）以及母亲吸烟（OR=18．960，95％CI=1．590—226．304）均与婴幼儿乳房发育相关。乳房发育阳性组比阴性组儿童身高偏矮（性别、年龄别身高z值-0．602±1．042vs.0．008±0．986，P〈0．05），体重偏轻（性别、年龄别体重Z值-0．479±0．648vs．0．005±0．987，P〈0．05），控制年龄、性别和父亲受教育程度后差异有统计学意义。而乳房发育的发生与否与婴幼儿的神经认知发育（t=-0．082，P〉0．05）和运动发育（t=1．054，P〉0．05）无明显相关性。结论我国婴幼儿乳房发育发生率与国外报道相近。0～48月婴幼儿中父亲受教育程度及母亲吸烟情况与乳房发育发生率具有相关性，同时乳房发育状况与体格生长显著相关，而与神经认知发育无关。

Objective The term ＂premature thelarche＂ refers to isolated breast development before 8 years of age in female, without any other signs of sexual maturation, while ＂gyneeomastia＂ is the presence of breast tissue in males. This study aimed to investigate the prevalence of premature thelarche and gyneeomastia in Chinese infants and toddlers, identify the potential risk factors, and explore the influence of early breast development on physical growth, mental development and psychomotor development. Method A total of 1 510 full term and healthy children at the age of 0 -48 months were sampled by stratified cluster random sampling method from 8 provinces from 2011 -2012. Weight, height and breast development were assessed by senior primary pediatricians, while Bayley Scale of Infant Development-I （BSID-I） was used to measure the mental developmental index （MDI） and psychomotor developmental index （PDI） for children aged 2 -30 months. Social-demographic Questionnaires were completed by the caregivers. Result Thecombined prevalence of premature thelarche and gynecomastia was 1.6% （23/1475）, girls 2. 2% （15/695）, boys 1. 0% （8/780）, all within 2 years of age. The birth weight, feeding patterns in first 4 months, delivery mode, weaning time and social economic status were not significantly associated with the breast development. However, lower father＇s education level （ OR = 3. 632, 95% CI = 1. 565 - 8.432） as well as smoking mother （OR = 18. 960, 95% CI = 1. 590- 226. 304） were significantly related to breast development even after adjusting for potential confounders. Lower weight （ - 0. 479 ± 0. 648 vs. 0. 005 ± 0. 987,P 〈0. 05） and height （ -0. 602± 1. 042 vs. 0. 008±0. 986,P 〈0. 05） Z score were found in breast development group, even after adjusting for age, gender and father＇ education level. Neither mental development （ t = - 0. 082,P 〉 0. 05 ） nor psychomotor development （ t = 1. 054, P 〉 0. 05 ） was associated with breast development. Conclusion We showed a similar prevalence of premature thelarche with the data reported in similar studies reported from other countries. Among the 0 -48 months old infants and toddlers, Father＇s education level and smoking mother were both related to breast development. Breast development was significantly associated with physical growth, but had no correlation with the mental or psychomotor development.