Association Of Pre-pregnancy BMI, Gestational Weight Gain With Neonatal Birth Weight

Objective To investigate the effect of pre-pregnancy BMI,total gestational weight gain,second- and third- trimester gestational weight gain on neonatal birth weight.Methods We collected pre-pregnancy BMI,second- and third- trimester gestational weight gain,neonatal birth weight of 978 women who took pre-pregnancy physical examination regularly and delivered in Capital medical university Xuanwu hospital from September 2014 to July 2015.We also collected social and economic information,including age,height,pre-pregnancy weight using questionnaire.We recorded the change of the pregnancy weight during pregnancy,child birth gestational age,birth weight and neonatal sex with self designed antenatal record.And analysis the effect of gestational weight gain,second- and third- trimester gestational weight gain rate on neonatal birth weight.Eventually 866 cases for data analysis.Results 1.Among the 866 women analyzed,pre-pregnancy underweight,normal,overweight and obesity women was 15.7%、57.5%、26.8%respectively.2.Among the 866 neonatal analyzed,there were 54 SGA neonatal,630 AGA neonatal,598 LGA neonatal and the incidence was 6.3%、72.7%、21.0% respectively.3.Pre-pregnancy BMI was positively correlated with neonatal birth weight(r=0.34,P<0.01).Second trimester gestational weight gain rate was positively correlated with neonatal birth weight(r=0.38,P<0.01).Third trimester gestational weight gain rate was positively correlated with neonatal birth weight(r=0.11,P=0.001).4.All pre-pregnancy BMI group second trimester gestational weight gain rate isgreater than third trimester gestational weight gain rate,and the difference was statistically significant(P < 0.001).5.Underweight women was associated with a lower risk of LGA(OR=0.442,95%CI:0.243-0.804).In contrast,excessive total gestational weight gain was associated with higher risk of LGA(OR,1.724,95%CI:1.210-2.456).For women with excessive gestational weight gain in the second and third trimester,a higher risk of LGA(OR2.933,95%CI:2.142-4.016)(OR2.914,95%CI:2.016-4.211)were observed.Conclusion 1.Overweight or obesity and gaining in excess of the IOM 2009 GWG guidelines strongly increase a woman’s chance of having a larger baby.2.Second trimester gestational weight gain rate was more positively correlated with neonatal birth weight.