One abnormal value in oral glucose tolerance test during pregnancy and type 2 diabetes risk: Insights from a 5-Year Follow-Up study

OBJECTIVES

To evaluate the risk of type 2 diabetes(T2D) following one abnormal value(OAbV) in an oral glucose tolerance test(oGTT) performed during pregnancy.

STUDY DESIGN

A retrospective analysis of parturients between 01.01.2017 and 31.12.2020 with 5 years of follow-up after delivery. Glucose levels during pregnancy were extracted from the computerized laboratory system of Meuhedet HMO and cross-tabulated with the Israeli National Registry of Diabetes. Women with multiple gestations or pregestational diabetes were excluded. Maternal characteristics and risk of T2D were stratified and compared between 3 groups: normal glucose status, OAbV in oGTT, and gestational diabetes. Statistical analysis included univariate analysis followed by survival analysis. Further analysis was stratified to women with and without obesity.

RESULTS

58,693 women entered the analysis. Following an adjustment to maternal age, obesity, hypertension, and hyperlipidemia, OAbV in oGTT was associated with a 1.8-fold increased risk of T2D in a 5-year follow-up compared to normal glucose status. When stratified by obesity, OAbV was associated with a 3.7-fold increase in T2D in women without obesity, however, was no longer a statistically significant predictor of T2D among women with obesity.

CONCLUSIONS

Women with OAbV oGTT during pregnancy are at increased risk for developing T2D over 5 years of follow-up.

One abnormal value or vomiting after oral glucose tolerance test in pregnancy: incidence and impact on maternal-fetal outcomes

OBJECTIVE

To analyze pregnancy outcomes of women with one abnormal value (OAV) during oral glucose tolerance test (OGTT) or OGTT-intolerance, compared with gestational diabetes mellitus (GDM) and normal glucose tolerance (NGT) pregnant women, according to whether they received any health intervention or not.

METHODS

An observational retrospective study was designed including pregnant women who gave birth at Hospital del Mar, Barcelona (Spain) during December/2014-July/2018. Baseline characteristics, pregnancy outcomes and health interventions were obtained from a database collected previously for other study. Inclusion criteria were singleton pregnancies with OAV or OGTT-intolerants who gave birth at the Hospital. GDM screening followed a two-step approach: 50 g O'Sullivan test and 100 g 3-hour OGTT if the former was abnormal.

RESULTS

From a total of 2,662 pregnancies, 326 (12.2%) had GDM, 87 OAV (3.3%), 65 OGTT intolerance (2.4%) and 2,184 were NGT women. First trimester HbA1c in both OAV and OGTT-intolerant women was significantly higher than in NGT group, and significantly lower than in GDM pregnants. No differences in obstetric outcomes were found between OGTT-intolerants and NGT/GDM groups. Treated OGTT-intolerants had greater gestational age at delivery than non-treated ones (weeks, 39.6 ± 1.2 vs 38.0 ± 4.0, respectively). In OAV women, significant differences were observed in newborns' birthweight (g, 3227.3 ± 500.8 vs 3351.1 ± 436.7, vs GDM) and gestational age at birth (weeks, 38.7 ± 1.8 vs 39.3 ± 1.9, vs NGT), but not in macrosomia/pre-eclampsia. No differences were found according to treatment in OAV.

CONCLUSIONS

OAV and OGTT-intolerants account for a third of pregnant women referred to Diabetes Unit. Their rates of preterm birth, pre-eclampsia and macrosomia were not different from NGT or GDM women.