Postpartum outcome and its risk factors of increased gestational diabetes mellitus according to the new diagnostic criteria

Objective To investigate the outcomes of increased gestational diabetes mellitus (GDM) and the influencing factors after the implementation of the new GDM diagnostic criteria. Methods A total of 1 439 GDM women who delivered in the Peking University First Hospital between May 1, 2011 and December 31, 2012 were studied and divided into two groups. Group I included the women who met the new GDM diagnostic criteria (fasting plasma glucose and 1 or 2 h plasma glucose levels for 75-g oral glucose tolerance test performed between 24 and 28 weeks of gestation were no less than 5.1, 10.0 and 8.5 mmol/L), but did not meet the National Diabetes Data Group (NDDG) criteria; and Group Ⅱ included the women who met the NDDG criteria only. Women in Group Ⅰ were further divided into two subgroups according to whether attending the one-day GDM outpatient visit. Follow-up rate and detecting rate of abnormal glucose metabolism at 6-12 weeks after delivery were analyzed. Chi-square test, t test and multivariate Logistic analysis were used for statistical analysis. Results There were 849 GDM women in GroupⅠ (59.0%, 849/1 439) and 590 (41.0%, 590/1 439) in Group Ⅱ. The follow-up rate in group Ⅰ was lower than in group Ⅱ [25.9%(220/849) vs 32.0%(189/590), χ2=6.112, P=0.013]. There were five cases of impaired fasting glucose and 34 impaired glucose tolerance in Group I; and four cases of impaired fasting glucose, 56 impaired glucose tolerance, eight impaired fasting glucose tolerance with impaired glucose tolerance and five diabetes mellitus in GroupⅡ; there were significant differences [17.7%(39/220) vs 38.6%(73/189), χ2=33.810, P=0.000]. (2) In GroupⅠ, the increased glucose level at 2 h in oral glucose tolerance test during pregnancy (OR=1.547, 95%CI: 1.038-2.306, P=0.032) and family history of diabetes mellitus (OR=1.879, 95%CI: 1.066-3.313, P=0.020) were risk factors for postpartum abnormal glucose metabolism, while breast-feeding was a protective factor (OR=0.290, 95%CI: 0.092-0.914, P=0.035). (3) In groupⅠ, the follow-up rate in those who attended the one-day GDM outpatient visit was higher than those who did not [30.7%(185/603) vs 14.2%(35/246), χ2=23.780, P=0.000], but the detecting rate of postpartum abnormal glucose metabolism were similar in women attending the one-day GDM outpatient visit and those not attending [17.8%(33/185) vs 17.1%(6/35), χ2=0.020, P=0.887]. Conclusions Increased GDM women still have glucose metabolism abnormality after delivery, especially those who have higher glucose level at 2 h after glucose intake in 75-g oral glucose tolerance test during pregnancy and who have a family history of diabetes mellitus. The one-day GDM outpatient visit may improve the follow-up rate for these women. Key words: Diabetes, gestational; Postpartum period; Follow-up studies