Pregnancy outcomes of gestational diabetes mellitus according to pre-gestational BMI in a retrospective multi-institutional study in Japan

Abstract

abstract. The aim of this study was to determine the effects of pre-gestational body mass index on pregnancy outcomes of women with gestational diabetes in Japan. A multi-institutional retrospective study was performed. We examined pregnant women who met the former criteria for gestational diabetes in Japan, receiving dietary intervention with self-monitoring of blood glucose with or without insulin therapy. Women with gestational diabetes were divided into three groups according to pre-gestational body mass index: body mass index <25 (control group), 25 ≤ body mass index <30 (overweight group), body mass index ≥30 (obese group). Data from a total of 1,758 eligible women were collected from 40 institutions. Participants included 960 controls, 426 overweight women, and 372 obese women with gestational diabetes. Gestational weight gain was highest in the control and lowest in the obese group. The prevalences of chronic hypertension and pregnancy induced hypertension were higher in the overweight and obese groups than in the control group. Multiple logistic regression analysis revealed pre-gestational body mass index, gestational weight gain, chronic hypertension, and nulliparity to be associated with the onset of pregnancy induced hypertension, while the 75-g OGTT results were unrelated to pregnancy induced hypertension. The prevalence of large-for-gestational age was lower in infants born to obese women than in those born to overweight or control women. The present results suggest that medical interventions for obese women with gestational diabetes may contribute to reducing the prevalence of large-for-gestational age but would not achieve marked reductions in maternal complications.

Impact of overweight and obesity on pregnancy outcomes in women with gestational diabetes – results from a retrospective multicenter study

“…Obesity and GD can lead to adverse outcomes, and, in our study, women who were overweight and obese prior to gestation had an increased risk of adverse pregnancy outcomes. Similar to reports in the literature, in our study, women who were overweight or obese were more often diagnosed with gestational hypertension or preeclampsia (11,15,20,21,23,24), labor was more likely to be induced (20), and the rate of cesarean section was higher (9,15,20,24,25). The risk of developing gestational hypertension was significantly higher in overweight and obese women.…”

“…Regarding neonatal outcomes, similar to what was described in previous reports, newborns of overweight and obese women were more likely to be macrosomic (11,21,(23)(24)(25) and LGA (20,21,23,24). This is of particular importance once these infants have higher risk of future development of metabolic syndrome and cardiovascular disease (13,20,30,31).…”

“…For that reason, the OGTT was not performed in a considerable proportion of women with overweight and obesity. This difference in screening methods could also explain the differences between our study and similar reports, regarding the lower frequencies of gestational hypertension (11,15), preeclampsia (6), macrosomia (6,11,23), and LGA newborns (6,15,20). Impaired fasting glucose levels due do insulin resistance and increased liver gluconeogenesis are common in obese women and may be present early in gestation.…”

“…In this study, there was a progressive increase in OR with the increasing BMI category regarding cesarean section. In some studies, the cesarean delivery rate reported in obese women with GD was approximately 40.0% (6,15,20), with one study reporting a 72.7% rate with a 3.2-fold increased risk of cesarean section (OR 3.26; IC 95% 1.57-6.76, p = 0.002) (24). The high percentage of cesarean delivery in this population could be due to suspected macrosomia or failure to induce labor.…”

“…The median fasting glucose levels were superior in overweight and obese women, but, contrasting with other reports, glucose levels following OGTT were similar between the four groups. Previous reports in the literature showed a gradual increase in glucose levels on 75g OGTT according to pre-pregnancy BMI (20,32). This is possibly a result of different diagnostic methods, as in most studies an OGTT after the 24 th week of gestation is the only screening approach.…”