Expected probability of congenital heart disease and clinical utility of fetal echocardiography in pregnancies with pre-gestational diabetes

Risk for fetal malformations and unfavorable neonatal outcomes in early-onset gestational diabetes mellitus

BACKGROUND

Early-onset gestational diabetes mellitus (GDM) is diagnosed before the 24th gestational week. Since early GDM is associated with first trimester hyperglycemia, many clinicians treat these women as having pre-GDM. However, whether early GDM increases the risk for unfavorable pregnancy outcomes and particularly for fetal malformations to a greater extent than late-onset GDM were not studied sufficiently. We aimed to examine the effect of early-onset GDM on unfavorable pregnancy outcomes.

METHODS

A retrospective cohort study of women with GDM delivering singletons during 2005-2018 was conducted. Women were divided into GDM diagnosed at the first (Trimester1; up to 13.6 weeks; N = 117), the second (Trimester2; up to 23.6 weeks; N = 126), and the third trimester (Trimester3; N = 2334). The primary outcomes were neonatal malformations and a composite of large-for-age newborns, hypoglycemia and hyperbilirubinemia treated with phototherapy. Comparisons were made between early- (Trimester1 + Trimester2-groups) and late-onset GDM (Trimester3-group), and between the three trimesters.

RESULTS

Fetal malformations were low and comparable between the trimester1, trimester2, trimester3 groups (2 (1.7%), 3 (2.4%), and 110 (4.7%), respectively). The composite neonatal complications was similar between the groups (68 (58%), 58 (46%), and 1087 (47%), respectively). In early-onset, the rates of neonatal hypoglycemia and shoulder dystocia were higher than in the late-onset GDM group (OR 95% CI 3.5 [2.0-6.1] and 10.3 [2.4-44.6], respectively). Macrosomia was higher in trimester1 compared with trimester2 and trimester3 cohorts (OR 95% CI 5.3 [1.7-16.9] and 2.8 [1.5-5.2], respectively).

CONCLUSIONS

The risk for fetal malformations was low and comparable between the first, second and third trimester GDM. Since the risks for macrosomia, shoulder dystocia, and neonatal hypoglycemia are higher in early-onset GDM, these women should undergo strict glycemic control, intensive monitoring, and careful neonatal evaluation.

Risk of major congenital heart disease in pregestational maternal diabetes is modified by hemoglobin A1c

OBJECTIVES

The association between pregestational diabetes mellitus (PDM) and risk of congenital heart disease (CHD) is well recognized; however, the importance of glycemic control and other coexisting risk factors during pregnancy is less clear. We sought to determine the relative risk (RR) of major CHD (mCHD) among offspring from pregnancies complicated by PDM and the effect of first-trimester glycemic control on mCHD risk.

METHODS

We determined the incidence of mCHD (requiring surgery within 1 year of birth or resulting in pregnancy termination or fetal demise) among registered births in Alberta, Canada. Linkage of diabetes status, maximum hemoglobin A1c (HbA1c) at < 16 weeks' gestation and other covariates was performed using data from the Alberta Perinatal Health Program registry. Risk of mCHD according to HbA1c was estimated as an adjusted RR (aRR), calculated using log-binomial modeling.

RESULTS

Of 1412 cases of mCHD in 594 773 (2.37/1000) births in the study period, mCHD was present in 48/7497 with PDM (6.4/1000; RR, 2.8 (95% CI, 2.1-3.7); P < 0.0001). In the entire cohort, increased maternal age (aRR, 1.03 (95% CI, 1.02-1.04); P < 0.0001) and multiple gestation (aRR, 1.37 (95% CI, 1.1-1.8); P = 0.02) were also associated with mCHD risk, whereas maternal prepregnancy weight > 91 kg was not. The stratified risk for mCHD associated with HbA1c ≤ 6.1%, > 6.1-8.0% and > 8.0% was 4.2/1000, 6.8/1000 and 17.1/1000 PDM/gestational diabetes mellitus births, respectively; the aRR of mCHD associated with PDM and HbA1c > 8.0% was 8.5 (95% CI, 5.0-14.4) compared to those without diabetes and 5.5 (95% CI, 1.6-19.4) compared to PDM with normal HbA1c (≤ 6.1%).

CONCLUSIONS

PDM is associated with a RR of 2.8 for mCHD, increasing to 8.5 in those with HbA1c > 8%. These data should facilitate refinement of referral indications for high-risk pregnancy screening. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Type 1 Diabetes: Management in Women From Preconception to Postpartum

CONTEXT

This review presents an up-to-date summary on management of type 1 diabetes mellitus (T1DM) among women of reproductive age and covers the following time periods: preconception, gestation, and postpartum.

EVIDENCE ACQUISITION

A systematic search and review of the literature for randomized controlled trials and other studies evaluating management of T1DM before pregnancy, during pregnancy, and postpartum was performed.

EVIDENCE SYNTHESIS

Preconception planning should begin early in the reproductive years for young women with T1DM. Preconception and during pregnancy, it is recommended to have near-normal glucose values to prevent adverse maternal and neonatal outcomes, including fetal demise, congenital anomaly, pre-eclampsia, macrosomia, neonatal respiratory distress, neonatal hyperbilirubinemia, and neonatal hypoglycemia.

CONCLUSION

Women with T1DM can have healthy, safe pregnancies with preconception planning, optimal glycemic control, and multidisciplinary care.