Researchers reported that women diagnosed with gestational diabetes prior to 24 weeks gestation were more likely to deliver a preterm baby compared with women diagnosed after 24 weeks….
Ivan Ngai, MD, instructor in obstetrics and gynecology at the Albert Einstein College of Medicine and Montefiore Medical Center in New York City stated that, "We found a 10.4-fold increase in preterm deliveries (prior to 37 weeks of pregnancy) in women who were diagnosed with gestational diabetes before 6 months of pregnancy (P<0.001)."
Compared with women diagnosed later in their pregnancy, gestational diabetes prior to 24 weeks was also associated with a greater body mass index (35.2 kg/m2 versus 34.6 kg/m2, P<0.01) and smaller birth weight (3,255 grams versus 3,448 grams, P<0.01).
In the retrospective study, Ngai and colleagues did not observe differences in the incidence of large for gestational age infants between the 305 women who were diagnosed with gestational diabetes before 24 weeks and the 401 women who were diagnosed after 6 months.
Ngai explained that in his population area, diabetes is highly prevalent so the standard of care in his practice is to screen all pregnant women for diabetes at their first visit to the prenatal clinic. In the study, women with a history of diabetes were excluded from the analysis.
He said that ACOG guidelines call for diabetes testing after 24 weeks of pregnancy, but the findings of his group’s study indicate that screening at the first antenatal visit should be performed, especially in populations that have a high incidence of diabetes.
They accessed the electronic medical records of women who were treated at the institution from 2008 to 2013. All women were screened at their first prenatal visit and then, if the screen was negative, the women were again screened. The researchers reported in a poster presentation, that the groups were similar when comparing cesarean delivery rates, preeclampsia, fetal demise, shoulder dystocia, and macrosomia. "In multivariate regression analysis, diagnosis of gestational diabetes before 24 weeks was an independent predictor of preterm birth with age and preeclampsia not significant in the model."
In the regression analysis, the researchers did not find an association for age in the prediction of preterm birth, although the women who had an earlier diagnosis of gestational diabetes were slightly older — 32.9 years versus 31.1 years for those who were diagnosed with diabetes after 6 months (P<0.01).They also did not find that preeclampsia was associated with preterm birth as 11.5% of women diagnosed with diabetes prior to 24 weeks were observed to have preeclampsia compared with 9.2% of women diagnosed after 24 weeks (P=0.38). There were no differences in outcome regarding preterm birth for women using insulin or glyburide, the researchers reported.
- Screening at the first antenatal visit should be performed, especially in populations that have a high incidence of diabetes.
- This study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
American College of Obstetricians and Gynecologists, Ngai I, et al "Outcome of pregnancy when gestational diabetes mellitus is diagnosed before or after 24 weeks of gestation" ACOG 2014.