孕期膳食铁及维生素A摄入水平对低出生体质量儿的影响研究

The impact of dietary vitamin A and iron intake during pregnancy on low birth weight infant

目的探讨不同孕期膳食铁及维生素A日均摄入水平对低出生体质量儿发生风险的影响,并分析其交互效应。方法选取2017年1月至2018年6月在某省级三甲医疗机构建卡就诊并在本院分娩的孕妇为研究对象,采用24 h膳食回顾法分别在孕早、孕中、孕晚期对孕妇进行膳食调查并随访至胎儿分娩。以多因素logistics回归模型分析不同孕期膳食维生素A与铁摄入量对低出生体质量儿发生风险的影响,用相乘模型分析其交互作用。结果8469例单胎孕妇中,分娩低出生体质量儿531例(6.27%),分娩巨大体质量儿583例(6.88%)。分娩低出生体质量儿孕妇孕期膳食维生素A及铁日均摄入量在孕早期(t=2.76、2.84,P=0.003、0.002)、孕中期(t=3.26、2.08,P=<0.01、0.019)、孕晚期(t=3.12、3.13,P<0.01)均低于分娩正常体质量儿孕妇摄入量。在控制相关混杂因素后,经多因素logistic回归分析显示,孕晚期膳食维生素A摄入水平低于EAR的孕妇分娩低出生体质量儿的风险增加12%(OR=1.12,95%CI:1.01~1.28),孕早、孕中、孕晚期膳食铁摄入量低于EAR的孕妇分娩低出生体质量儿的风险分别增加36%(OR=1.36,95%CI:1.09~1.70)、18%(OR=1.18,95%CI:1.05~1.33)、22%(OR=1.22,95%CI:1.07~1.39);交互作用分析显示,孕期膳食维生素A与铁摄入量不足对低出生体质量儿的发生风险存在相乘的交互作用(OR孕早=1.28,95%CI:1.04~1.57;OR孕中=1.15,95%CI:1.06~1.25;OR孕晚=1.15,95%CI:1.05~1.28)。结论孕期膳食维生素A及铁摄入量低于RNI将增加低出生体质量儿的发生风险,故孕期适量增加维生素A及铁摄入可降低LBW的出生。

Objective To discuss the impact of dietary vitamin A and iron daily intake during pregnancy on low birth weight infant,and to analyze the interactive effect.Methods A total of 8469 pregnant women who delivered babies in our hospital from January 2017 to June 2018 were enrolled and a questionnaire survey was conducted on their daily diets during the first,second and third trimester using 24 hours diet retrospective survey method.Multivariate logistic regression model was used to analyze the impact of vitamin A and iron intake on the risk of low birth rate of infants.Multiplication model was used for the interaction analysis.Results Among 8469 infants delivered,531(6.27%)were low birth weight babies,583(6.88%)were over weight babies.The amount of daily vitamin A and iron intake of pregnant women who delivered low body weight infants were significantly lower compared with those who gave birth with normal body weight babies during the first trimester(t=2.76,2.84,P=0.03,0.002),second trimester(t=3.26,2.08,P<0.01,0.019)and third trimester(t=3.12,3.13,P<0.01).After adjusted for age,education level,monthly income,employment status during pregnancy,smoking,weight gain,multivitamin and iron supplementation,history of premature and total energy intake,multivariate logistic regression analysis showed that insufficient dietary intake of vitamin A during late pregnancy increased the risk of low body weight infants by 12%(OR=1.12,95%CI:1.01-1.28),while insufficient dietary iron intake during early,mid and late pregnancy(<EAR)increased the risk of low weight infants by 36%(OR=1.36,95%CI:1.09-1.70),18%(OR=1.18,95%CI:1.05-1.33)and 22%(OR=1.22,95%CI:1.07-1.39),respectively.Interaction analysis showed a multiplicative interaction between insufficient dietary intake of vitamin A and iron and the risk of low body weight infants during the first trimester(OR=1.28,95%CI:1.04-1.57),second trimester(OR=1.15,95%CI:1.06-1.25)and third trimester(OR=1.15,95%CI:1.05-1.28).Conclusions Insufficient intake of vitamin A and iron during pregnancy increases the risk of low birth weight infants.Therefore,it is suggested that pregnant women should increase the amount of vitamin A and iron intake to lower the risk of low body weight of infants.