Prevalence of macrosomia and its risk factors in China: a national survey in 2011

Abstract

Objective To investigate the prevalence of macrosomia in China and the risk factors.Methods By stratified cluster random sampling,the medical records of 101 723 singleton term infants born in 37 hospitals nation wide (in 14 provinces) from January 1,2011 to December 31,2011 were reviewed.Adjusted odd ratio (aOR) and 95％ confidence interval (CI) were used to describe the risk factors.Population attribute risk (PAR) was used to quantitatively describe the associations between risk factors and the prevalence of macrosomia.Results The general prevalence of macrosomia was 7.3％ (7403/101 723).The prevalence varied among provinces (4.1％ to 13.4 ％).Logistic regression analysis showed that macrosomia were positively associated with living in northern China (aOR =1.4,95 ％ CI:1.2 ～ 1.6,PAR =19.9 ％),maternal age ≥ 35 (aOR =1.1,95％ CI:0.9～1.3,PAR=8.7％),pre-pregnant BMI≥28 (aOR=3.6,95％ CI:2.9～4.5,PAR=15.1％),gravidity＞1 (aOR=1.2,95％ CI:1.1～1.4,PAR=10.8％),parity＞1 (aOR=1.8,95％ CI:1.5～ 2.1,PAR=10.1％),maternal height≥160 cm (aOR =1.6,95％ CI:1.4～ 1.9,PAR=29.5％),gestational weight gain (GWG) ≥16 kg (aOR=2.2,95％ CI:1.9～2.4,PAR=25.2％),gestational diabetes mellitus (aOR=1.2,95％ CI:1.0～ 1.3,PAR =3.2％),gestational weeks≥40(aOR=2.4,95％ CI:2.1～ 2.7,PAR=34.4％)and baby boy (aOR=l.6,95％ CI:1.4～1.8,PAR=25.4％).Maternal BMI,gestational week and GWG were most strongly associated with macrosomia.Conclusions The prevalence of macrosomia varied dramatically between different areas in China.Pre-pregnancy BMI,gestational week and GWG,as the main modifiable risk factors for macrosomia,need more attention from health care providers. Key words: Fetal macrosomia; Prevalence; Risk factors; Perinatal care