Late-pregnancy dysglycemia in obese pregnancies after negative testing for gestational diabetes and risk of future childhood overweight: An interim analysis from a longitudinal mother-child cohort study.
Gomes Delphina,von Kries Rüdiger,Delius Maria,Mansmann Ulrich,Nast Martha,Stubert Martina,Langhammer Lena,Haas Nikolaus A,Netz Heinrich,Obermeier Viola,Kuhle Stefan,Holdt Lesca M,Teupser Daniel,Hasbargen Uwe,Roscher Adelbert A,Ensenauer Regina
BACKGROUND:Maternal pre-conception obesity is a strong risk factor for childhood overweight. However, prenatal mechanisms and their effects in susceptible gestational periods that contribute to this risk are not well understood. We aimed to assess the impact of late-pregnancy dysglycemia in obese pregnancies with negative testing for gestational diabetes mellitus (GDM) on long-term mother-child outcomes. METHODS AND FINDINGS:The prospective cohort study Programming of Enhanced Adiposity Risk in Childhood-Early Screening (PEACHES) (n = 1,671) enrolled obese and normal weight mothers from August 2010 to December 2015 with trimester-specific data on glucose metabolism including GDM status at the end of the second trimester and maternal glycated hemoglobin (HbA1c) at delivery as a marker for late-pregnancy dysglycemia (HbA1c ≥ 5.7% [39 mmol/mol]). We assessed offspring short- and long-term outcomes up to 4 years, and maternal glucose metabolism 3.5 years postpartum. Multivariable linear and log-binomial regression with effects presented as mean increments (Δ) or relative risks (RRs) with 95% confidence intervals (CIs) were used to examine the association between late-pregnancy dysglycemia and outcomes. Linear mixed-effects models were used to study the longitudinal development of offspring body mass index (BMI) z-scores. The contribution of late-pregnancy dysglycemia to the association between maternal pre-conception obesity and offspring BMI was estimated using mediation analysis. In all, 898 mother-child pairs were included in this unplanned interim analysis. Among obese mothers with negative testing for GDM (n = 448), those with late-pregnancy dysglycemia (n = 135, 30.1%) had higher proportions of excessive total gestational weight gain (GWG), excessive third-trimester GWG, and offspring with large-for-gestational-age birth weight than those without. Besides higher birth weight (Δ 192 g, 95% CI 100-284) and cord-blood C-peptide concentration (Δ 0.10 ng/ml, 95% CI 0.02-0.17), offspring of these women had greater weight gain during early childhood (Δ BMI z-score per year 0.18, 95% CI 0.06-0.30, n = 262) and higher BMI z-score at 4 years (Δ 0.58, 95% CI 0.18-0.99, n = 43) than offspring of the obese, GDM-negative mothers with normal HbA1c values at delivery. Late-pregnancy dysglycemia in GDM-negative mothers accounted for about one-quarter of the association of maternal obesity with offspring BMI at age 4 years (n = 151). In contrast, childhood BMI z-scores were not affected by a diagnosis of GDM in obese pregnancies (GDM-positive: 0.58, 95% CI 0.36-0.79, versus GDM-negative: 0.62, 95% CI 0.44-0.79). One mechanism triggering late-pregnancy dysglycemia in obese, GDM-negative mothers was related to excessive third-trimester weight gain (RR 1.72, 95% CI 1.12-2.65). Furthermore, in the maternal population, we found a 4-fold (RR 4.01, 95% CI 1.97-8.17) increased risk of future prediabetes or diabetes if obese, GDM-negative women had a high versus normal HbA1c at delivery (absolute risk: 43.2% versus 10.5%). There is a potential for misclassification bias as the predominantly used GDM test procedure changed over the enrollment period. Further studies are required to validate the findings and elucidate the possible third-trimester factors contributing to future mother-child health status. CONCLUSIONS:Findings from this interim analysis suggest that offspring of obese mothers treated because of a diagnosis of GDM appeared to have a better BMI outcome in childhood than those of obese mothers who-following negative GDM testing-remained untreated in the last trimester and developed dysglycemia. Late-pregnancy dysglycemia related to uncontrolled weight gain may contribute to the development of child overweight and maternal diabetes. Our data suggest that negative GDM testing in obese pregnancies is not an "all-clear signal" and should not lead to reduced attention and risk awareness of physicians and obese women. Effective strategies are needed to maintain third-trimester glycemic and weight gain control among otherwise healthy obese pregnant women.
Postpartum glucose intolerance following early gestational diabetes mellitus.
American journal of obstetrics & gynecology MFM
BACKGROUND:Patients with gestational diabetes mellitus are at increased risk for type 2 diabetes mellitus or glucose intolerance postpartum compared with those without diabetes mellitus. OBJECTIVE:We aimed to evaluate the association between early gestational diabetes mellitus and postpartum dysglycemia compared with gestational diabetes mellitus diagnosed by routine screening in a cohort of patients with obesity. STUDY DESIGN:This was a secondary analysis of a randomized controlled trial of patients with obesity and singleton, nonanomalous gestations that compared early gestational diabetes mellitus screening at 14 to 20 weeks of gestation with routine screening at 24 to 28 weeks of gestation. Patients were included in this analysis if they were diagnosed with gestational diabetes mellitus at the primary study site. The primary outcome was postpartum dysglycemia, defined as any abnormality on 2-hour oral glucose tolerance test 6 weeks postpartum or clinical diagnosis based on hyperglycemia requiring pharmacotherapy after delivery with deferred glucose tolerance test. Maternal characteristics and outcomes were compared in bivariable analysis, and logistic regression estimated the association between early gestational diabetes mellitus and postpartum dysglycemia. RESULTS:Of 119 patients included in this analysis, 30 were diagnosed by screening at <20 weeks of gestation and 89 at 24 to 28 weeks of gestation. Patients were overall similar in baseline characteristics. Patients with early gestational diabetes mellitus were more likely to have postpartum dysglycemia than those with gestational diabetes mellitus diagnosed with routine screening (36.7% vs 14.6%; odds ratio, 3.38; 95% confidence interval, 1.31-8.73). Most patients with early gestational diabetes mellitus who had postpartum dysglycemia were diagnosed clinically (n=7/11), whereas none of the patients with gestational diabetes mellitus established by routine testing were diagnosed with postpartum dysglycemia clinically. All (100%) patients with early gestational diabetes mellitus who completed a postpartum glucose tolerance test had dysglycemia compared with only 45% of patients with gestational diabetes mellitus diagnosed on routine screening. The proportion of patients who followed up for postpartum visits and the timing of follow-up were similar between groups. Postpartum glucose tolerance test completion was low but also similar between groups. CONCLUSION:Although postpartum glucose tolerance test completion is low, patients with gestational diabetes mellitus before 20 weeks of gestation, seem to be at higher risk for postpartum dysglycemia than those with gestational diabetes mellitus diagnosed at routine screening in a cohort of patients with obesity. Larger studies are needed to confirm these findings, but postpartum follow-up and diabetes mellitus testing may be even more important to improve long-term health in patients with early gestational diabetes mellitus.