Association between birth season and physical development in children under 3 years old residing in low-income counties in western China.

Fangliang Lei,Baibing Mi,Ruo Zhang,Jia Ying,Jiaomei Yang,Danmeng Liu,Pengfei Qu,Xiaofeng Zhang,Shanshan Li,Hong Yan,Shaonong Dang,Hongwei Xu

doi:10.1371/journal.pone.0187029

Abstract

ObjectiveTo explore the association between birth season and physical development and provide a necessary reference value to inform the implementation of public health services.DesignCross-sectional study.SettingForty-five counties in ten provinces in western China in 2005.SubjectsA sample of 13,387 children under 3 years old and their mothers were recruited using a stratified, multistage, cluster random sampling method.ResultsThe results of the circular distribution analysis suggested that stunting and underweight exhibited time aggregation (Z = 32.57, P<0.05; Z = 10.42, P<0.05) among children under 3 years old. The Z − value for wasting, however, was not statistically significant (P>0.05). The generalized linear mixed models showed that children born in the summer were less likely to exhibit stunting (OR: 0.74~0.97) than were children born in the winter after adjusting for confounders, but no significant differences were identified for the other seasons. In addition, among children aged 25 to 36 months, those born in the summer and autumn were less likely to exhibit stunting after adjusting for confounders than were children born in the winter, but the association between birth in spring and stunting was not statistically significant.ConclusionsStunting was associated with season of birth among children under 3 years old in low-income counties in western China, especially children aged 25 to 36 months, and children born in the summer and autumn were less likely to exhibit stunting than were children born in the winter.

Highlights

Seasonal patterns have been identified in childhood growth parameters, including birth weight and length[1,2,3,4,5] and body size in both children[6] and adults[7, 8], and both developing and developed countries
Association between birth season and physical development in children under 3 years old present study, and these sponsors had no role in the design, analysis, interpretation of data, or composition of this article or the decision to submit the paper for publication
Stunting was associated with season of birth among children under 3 years old in lowincome counties in western China, especially children aged 25 to 36 months, and children born in the summer and autumn were less likely to exhibit stunting than were children born in the winter

Summary

Introduction

Seasonal patterns have been identified in childhood growth parameters, including birth weight and length[1,2,3,4,5] and body size in both children[6] and adults[7, 8], and both developing and developed countries. An October—April peak and May—September nadir were reported for height among children in north Poland[5, 6], while in Dunedin, New Zealand, birth weight and length were found to be highest among those with October (spring) births and lowest among those with January (summer) births[8]. A Chinese study suggested that the seasonal effects on weight gain and length gain were largely independent in Shanghai; in addition, infants tended to grow faster in height in spring and summer and faster in weight and BMI in autumn and winter[13]. The different conclusions of the aforementioned studies might have resulted from various factors, including regional and study population differences

Methods

Results

Conclusion