Clinical Study On The Risk Factors For Gestational Diabetes Mellitus In Successive Pregnancies

Objectives: 1.To study the risk factors for gestational diabetes mellitus(GDM)among Chinese multipara.2.To study the risk factors for recurrent gestational diabetes mellitus(RGDM)among Chinese multipara.Methods: 1.We conducted an epidemiological method of retrospective case-control study to investigate the risk factors.2.All patients were included for they had two consecutive pregnancies records in the International Peace Maternity and Child Health Hospital,Shanghai Jiao Tong University School of Medicine,from January 2012 to January 2017.3.In first part,women diagnosed with GDM in subsequent pregnancy were defined as the case group.Women with normal glucose tolerance were matched as the control group at a ratio of 1:2 with respect to age.4.In second part,women diagnosed with RGDM were considered as the case group,whereas women with only once GDM in index pregnancy were defined as the control group.5.Maternal information,such as socio-demographic characteristics,previous delivery experience,75-g oral glucose tolerance test(OGTT),first-trimester biochemical parameters in index and subsequent pregnancy were obtained from their medical records.6.All variables were first assessed by one-sample Kolmogorov-Smirnov test.The difference between groups was calculated by independent samples t-test for the continuous variables and Chi-square test or Fisher's exact test for dichotomous variables.The odds ratio(OR)and 95% confidence interval(CI)were computed and adjusted for potential confounding factors via univariate and multivariate logistic regression analysis,respectively.Results: 1.The risk of GDM was associated with the traditional risk factors including heavier birth weight of former infant(AOR=1.01,95% CI=1.00-1.01),higher one-hour(AOR=1.94,95% CI=1.48-2.55)and two-hour(AOR=1.94,95% CI=1.41-2.67)glucose values at 75-g OGTT in index pregnancy.2.The weight change between pregnancies(AOR=1.25,95% CI=0.99-1.58)became statistical insignificant after adjustment.3.Two newly identified risk factors related to GDM including greater first-trimester total cholesterol(AOR=1.49,95% CI=1.08-2.05)and triglyceride concentration(AOR=1.93,95% CI=1.19-3.11).4.The case group presented higher first-trimester fasting plasma glucose(AOR=1.92,95% CI=1.07-3.44),total cholesterol(AOR=1.47,95% CI=1.11-1.95)and triglyceride concentration(AOR=1.77,95% CI=1.20-2.60)in subsequent pregnancy.5.The frequency of RGDM among Chinese population was 54.9% based on our hospital.6.The risk of RGDM was associated with the traditional risk factors including greater one-hour glucose value(AOR=1.43,95% CI=1.09-1.87)at 75-g OGTT in index pregnancy.7.A newly investigated risk factor related to RGDM was lower first-trimester fasting plasma glucose(AOR=0.24,95% CI=0.10-0.63)in index pregnancy.8.Although the first-trimester triglyceride in index pregnancy(AOR=1.77,95% CI=0.96-3.27)showed no statistical significance after adjustment,the higher triglyceride concentration in subsequent pregnancy(AOR=1.89,95% CI=1.13-3.16)strongly correlated to RGDM.Conclusions: 1.Apart from the traditional risk factors for GDM,higher first-trimester total cholesterol and triglyceride in index pregnancy may play dominant roles in the occurrence of GDM.2.Although the glucose values at 75-g OGTT remain in normal range between two groups,the case group manifested the decrease of insulin sensitivity compared with the control group.3.The frequency of RGDM among Chinese multipara based on our hospital is similar with the pooled incidence among Asian population,and also higher than Caucasian population.4.In addition to the traditional risk factors for RGDM,lower first-trimester fasting plasma glucose in index pregnancy and higher triglyceride concentration in subsequent pregnancy are remarkable related to RGDM.5.We suppose that the relative higher glucose and lipid profiles may persist from index pregnancy to subsequent pregnancy in the case groups,and the abnormalities become more severe than before,leading to the occurrence of GDM and RGDM.6.Early examination of these biochemical parameters is beneficial for prompt diagnosis of women with high risk.7.Healthy diet and proper physical activities may impose great impact on blocking the persistent change of glucose and lipid profiles,however,further study is needed to confirm their specific roles in lowering the occurrence of GDM and RGDM.