The Effect Of Pre-pregnancy BMI And Pregnancy Weight Gain On Birth Weight And Pregnancy Outcome

Objective: By studying the influence of different Pre-pregnancy women's body mass index and weight gain during pregnancy on the birth weight and pregnancy outcome,explore the reasonable range of pre-pregnancy BMI and pregnant women's weight gain during pregnancy,so as to provide a theoretical basis for weight management during pregnancy.Through effective maternal body weight control,reduce the incidence of complications during pregnancy and labor,promote natural childbirth to reduce the rate of caesarean section and ensure the safety of mother and child.Method: 740 cases of primipara are selected in our hospital in June 2015-August2016.Record maternal age,occupation,gestational age,height,weight usually before pregnancy,maternal weight,gestational hypertension and the incidence of diabetes in pregnancy,mode of delivery,labor bleeding,neonatal birth weight and fetal distress.To calculate the pre-pregnancy BMI and weight gain during pregnancy.The calculated BMI before pregnancy is divided into four groups: low group,normal group,overweight and obesity group;according to the 2009 U.S Institute of Medicine(IOM)recommended weight gain during pregnancy: weight gain during pregnancy are divided into 3 subgroups: weight gain too little group,normal group,excessive weight gain group.In the pre-pregnancy BMI normal group and the group of normal weight group for the control of maternal age,gestational age,occupation,gestational hypertension,gestational diabetes,mode of delivery,birth weight and macrosomia,postpartum hemorrhage and fetal distress are investigated.SPSS 17.0 was used for data analysis.The risk of pregnancy complications was expressed by relative risk(RR)and 95%confidence interval(CI).Result:(1)Taking normal BMI as control group before pregnancy,we compare theincidence of hypertensive disorder complicating pregnancy between BMI pre-pregnancy,find that with the increase of BMI before pregnancy,the incidence of hypertensive disorder complicating pregnancy gradually increased.The difference is statistically significant(P<0.05).In the normal BMI group pre-pregnancy,weight gain in normal group as control group,the overweight group is RR value 1.3,excessive weight gain during pregnancy is a risk factor for the onset of hypertensive disorder complicating pregnancy.There is no significant difference(P>0.05).(2)In the pre-pregnancy BMI normal group as control group,compare the incidence of gestational diabetes mellitus in each group,the pre-pregnancy BMI low group RR value 0.594,suggesting that low pre-pregnancy body mass index is the protective factors of gestational diabetes mellitus;overweight and obesity groups relative risk are 1.258 and 2.469,suggesting that overweight and obesity BMI groups pre-pregnancy are the risk factors of gestational diabetes mellitus,the difference is statistically significant(P<0.05).In the normal weight group with weight gain as the control group,the overweight group is RR value 1.235,suggesting that excessive weight gain during pregnancy is a risk factor for gestational diabetes mellitus.There is no significant difference(P>0.05).(3)With the increase of BMI pre-pregnancy and weight during pregnancy,the incidence of spontaneous labor is decreasing,and the incidence of cesarean section is higher and higher.There is a significant difference(P<0.05).In the pre-pregnancy BMI normal group as control group,the RR values of the super recombinant and the obese group are 1.170 and 1.385 respectively,suggesting that both of the two groups are the risk factors for cesarean section.The RR values of overweight and overweight groups are 0.739 and 1.160,the difference is statistically significant(P<0.05),weight gain during pregnancy is closely related to the incidence of cesarean section.(4)Pre-pregnancy BMI is closely related to the birth weight of newborns and the incidence of gigantic infants.The RR values of pre-pregnancy BMI and obese groups are 1.491 and 2.676,suggesting that overweight and obesity before pregnancy are the risk factors for the occurrence of gigantic infants,the difference is statisticallysignificant(P<0.05).In the normal weight group with weight gain as the control group,excessive weight gain in group RR value 4.861,RR95%CI2.850-8.291,suggesting that excessive weight gain during pregnancy is a risk factor for the occurrence of giant infants,the difference is statistically significant(P<0.05).(5)Taking normal BMI as control group before pregnancy,the incidence of postpartum hemorrhage is not increase with the increase of pre-pregnancy BMI,There is no significant difference(P>0.05).Taking normal weight gain as a control,it is found that the probability of postpartum hemorrhage gradually increases along with the weight gain during pregnancy,and the RR value of overweight group is 1.509,excessive weight gain during pregnancy is a risk factor for postpartum hemorrhage,the difference is not statistically significant(P>0.05).(6)The incidence of fetal distress in pre-pregnancy BMI low group,super recombinant and obese group is higher than that in BMI normal group before pregnancy,the difference is not statistically significant(P>0.05).Among them,the ratio of RR in pre-pregnant BMI low group,overweight group and obesity group is 1.807,1.541 and1.450,three of them are risk factors for fetal distress.The incidence of fetal distress in low weight and overweight groups during pregnancy is higher than that in the normal weight gain group,the RR ratios are 2.532 and 1.190,respectively,suggesting that they are risk factors for fetal distress,the difference is statistically significant(P<0.05).Conclusion: Appropriate pre-pregnancy BMI and weight gain during pregnancy can effectively reduce the incidence of hypertensive disorder complicating pregnancy and gestational diabetes,and reduce the probability of cesarean section,fetal macrosomia,postpartum hemorrhage and fetal distress.Therefore,reasonable weight management can not only make the mother and child sufficient nutrition,but also ensure the safety of the mother and child.