The Study On Risk Factors Of Gestational Diabetes Mellitus And Its Impact On Large For Gestational Age Infants

Objective:Gestational diabetes mellitus(GDM) was defined as any degree of glucose intolerance with onset or first recognition during pregnancy, whether or not the condition persisted after pregnancy, and not excluding the possibility that unrecognized glucose intolerance may have antedated or begun concomitantly with the pregnancy. GDM is a common metabolic complication during pregnancy. A number of studies have confirmed that no matter from the perspective of genetic or environmental factors, the GDM and type 2 diabetes mellitus(type 2 diabetes mellitus, T2DM) both have similar pathogenesis. As a kind of high risk factors, GDM carries risks for the mother and neonate. The risk of adverse pregnancy outcomes,such as gestational hypertension, preeclampsia, placental abruption, premature birth,large for gestational age(LGA), hyperbilirubinemia, neonatal hypoglycemia, fetal abnormalities may increase. Meanwhile, GDM will have a profound impact on maternal and children’s health. Studies had found that Women with a history of GDM had a greatly increased subsequent risk for diabetes and the risk of offspring suffering from obesity, T2 DM, cardiovascular disease and other chronic diseases also greatly increased. Based on the above research, this study tries to research on the risk factors influencing the pathogenesis of GDM and to what extent plasma glucose of 75 g oral glucose tolerance test(75g OGTT) and maternal BMI influencing neonatal birth weight, especially for delivering LGA.Methods:This study selected those pregnant women who do routine antenatal examination in Affiliated Hospital of Jining Medical College from Jan. 2014 to August 2014.And all the participants took 75 g oral glucose tolerance test(75g OGTT). The diagnosis of GDM is made when any of the following plasma glucose values are exceeded: FPG ≥5.1mmol/L or 1h PG≥10.0mmol/L or 2h PG≥8.5mmol/L according to American Diabetes Association(ADA) diagnostic criteria of GDM. This study selected 790 cases diagnosed with GDM as GDM group, 478 cases diagnosed with Normal Glucose Tolerance(NGT) as NGT group respectively and follow-up until they delivered. Clinical characteristics such as mother’s age, height, weight before pregnancy, weight gain, family history of diabetes, history of macrosomia, history of polycystic ovary syndrome, glucose levels of 75 g glucose tolerance test and neonatal birth weight, body length, gestational weeks of birth and other clinical data were recorded. Rule out those who did not deliver in our hospital, stillbirth, twins pregnancy, pre-pregnancy hypertension, heart disease, autoimmune disease, et al.Finally 507 cases were enrolled in GDM group, 326 cases were enrolled in NGT group. This study tries to analyze risk factors influencing the pathogenesis of GDM retrospectively; then to research on the effect of maternal pre-pregnancy body mass index(BMI), the increment value of BMI and plasma glucose of 75 OGTT on neonatal birth weight, especially on risk of delivering LGA.Result:1.Pre-pregnancy body mass index(BMI), family history of diabetes, polycystic ovary syndrome(PCOS), history of delivering macrosomia, gravidity and parity history in GDM group and those in NGT group were significantly different,respectively(all P<0.05). Pre-pregnancy body mass index, family history of diabetes,age were independent risk factors for GDM. Because the sample size of history of delivering macrosomia and PCOS is not enough, we need to increase sample size for further research.2.GDM group had a significantly higher risk of delivery LGA than NGT group(47.30%vs31.30%, P<0.05), excessive fetal development may be related to intrauterine hyperglycemia environment.3.Adjusting for age, DM history, history of delivering macrosomia and gestational weeks of birth, it suggested that 2-h plasma glucose level of 75 g OGTT and increment of BMI was independent risk factors for the delivery of LGA infants.And everyone unit increment in 75 g OGTT 2-h plasma glucose level, the risk of LGA may increase by 29%(OR=1.29, 95%CI: 1.05-1.58, P=0.02); similarly, everyone unitincrement in added value of BMI, the risk of LGA may increase by 20%(OR=1.20,95%CI: 1.02-1.42, P=0.03).Conclusion:1.Pre-pregnancy body mass index(BMI), family history of diabetes, polycystic ovary syndrome(PCOS), history of delivering macrosomia, gravidity and parity history in GDM group and those in NGT group were significantly different,respectively(all P<0.05). Pre-pregnancy body mass index, family history of diabetes,age were independent risk factors for GDM.2.GDM group had a significantly higher risk of delivery LGA than NGT group(47.30%vs31.30%, P<0.05), excessive fetal development may be related to intrauterine hyperglycemia environment.3.Adjusting for age, DM history, history of delivering macrosomia and gestational weeks of birth, it suggested that 2-h plasma glucose level of 75 g OGTT and increment of BMI was independent risk factors for the delivery of LGA infants.And everyone unit increment in 75 g OGTT 2-h plasma glucose level, the risk of LGA may increase by 29%(OR=1.29, 95%CI: 1.05-1.58, P=0.02); similarly, everyone unit increment in added value of BMI, the risk of LGA may increase by 20%(OR=1.20,95%CI: 1.02- 1.42, P=0.03).