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.