Effects of different glucose tolerance results and body mass index on pregnancy outcomes among pregnant women with gestational diabetes mellitus

Objective To explore the relationship between different glucose tolerance results and adverse pregnancy outcomes among women with gestational diabetes mellitus（GDM）, so as to provide evidence for further individualized diagnosis and treatment.

Methods Pregnant women who registered and delivered in the obstetrics department of Fujian Maternity and Child Health Hospital from January 1^st, 2017 and December 30^th, 2018 were recruited as research subjects. They received 75 g oral glucose tolerance test（OGTT） at 24－28 weeks of gestation. They were diagnosed as GDM according to the “Standars of Medical Care in Gestational Diabetes Mellitus （2014）”. They were divided into three groups： fasting-abnormal, post-load abnormal and combined abnormal based on OGTT results. The incidence of maternal and infant adverse outcomes was compared between three groups.

Results A total of 5 026 pregnant women were enrolled in the study, among which fasting-abnormal group, post-load abnormal group and combined abnormal group accounted for 15.70%, 71.05% and 13.25%, respectively. Multiple regression analysis showed that the incidence of large for gestational age（LGA） and macrosomia in the fasting-abnormal group were 1.49 times （OR = 1.49,95% CI：1.23－1.80） and 1.70 times （OR = 1.70,95% CI：1.23－2.36） as high as those in the post-load abnormal group, respectively. The incidences of premature rupture of membranes,cesarean section, LGA, macrosomia and gestational hypertension in the combined abnormal group were 1.27 times （OR = 1.27,95% CI：1.06－1.52）, 1.53 times（OR = 1.53,95% CI：1.29－1.81）, 1.81 times（OR = 1.81,95% CI：1.49－2.20）, 2.35 times （OR = 2.35,95% CI：1.71－3.22）, and 2.08 times （OR = 2.08,95% CI：1.56－2.78） as high as those in the post-load abnormal group. In the fasting-abnormal group, pregnant women with pre-pregnancy body mass index （BMI）≥24 kg/m² had higher risk of adverse outcomes, such as gestational hypertension（OR = 6.01,95% CI：1.47－24.67）, premature rupture of membranes （OR = 2.72,95% CI：1.31－5.67）, caesarean section （OR = 2.10,95% CI：1.04－4.27）, macrosomia （OR = 4.18,95% CI：1.42－12.27） than those of women with BMI < 24 kg/m², and the differences were statistically significant （P < 0.05）. In the post-load abnormal group, the incidence of hypertensive disorders （OR = 2.39,95% CI：1.70－3.35）, caesarean section （OR = 1.91,95% CI：1.58－2.31）, LGA（OR = 1.61,95% CI：1.28－2.04）, macrosomia （OR = 1.94,95% CI：1.30－2.90） were higher among women with BMI≥24 kg/m² than those of women with BMI < 24 kg/m², and the differences were statistically significant（P < 0.05）.

Conclusion The results of glucose tolerance in pregnant women with GDM are associated with adverse perinatal outcomes. Combined with pre-pregnancy BMI assessment, pre-pregnancy BMI≥24 kg/m² will increase adverse pregnancy outcomes in the fasting-abnormal group and post-load abnormal group.