Maternal Thinness and Obesity and Customized Fetal Weight Charts

The NDDG criteria versus the IADPSG or the ADA criteria for diagnosing early-onset gestational diabetes mellitus or abnormal glucose tolerance

OBJECTIVE

To analyze the effects of substituting the National Diabetes Data Group (NDDG) criteria with the International Association of Diabetes and Pregnancy Study Groups (IADPSG) or American Diabetes Association (ADA) criteria for the diagnosis of early-onset gestational diabetes mellitus (Early-GDM) or first trimester abnormal glucose tolerance (1 t-AGT).

METHODS

A retrospective cohort study was conducted of 3200 women: 400 with Early-GDM, 800 with GDM, and 2000 with Non-GDM, according to the NDDG criteria. Rates of women with missed and new Early-GDM according to the IADPSG or ADA criteria were calculated. Multivariate logistic regression analysis was used to compare perinatal outcomes between groups.

RESULTS

Using the IADPSG criteria, 61.6% of women with Early-GDM according to the NDDG were undiagnosed (Missed-Early-GDM group), and 25.9% of women with GDM and 15.7% of women with Non-GDM were diagnosed with Early-GDM (New-Early-GDM groups). Perinatal outcomes were worse in Missed-Early-GDM than in Non-GDM and better in New-Early-GDM groups than in the Early-GDM group. According to the ADA recommendations, only 11.8% of women with Early-GDM according to the NDDG criteria were diagnosed.

CONCLUSION

Replacing the NDDG recommendations for the diagnosis of Early-GDM with the IADPSG or ADA criteria would mean depriving a large number of women with AGT and higher risk of adverse perinatal outcomes from early treatment and treating others with lower risk.

Abnormal Maternal Body Mass Index and Customized Fetal Weight Charts: Improving the Identification of Small for Gestational Age Fetuses and Newborns

BACKGROUND

Obesity and thinness are serious diseases, but cases with abnormal maternal weight have not been excluded from the calculations in the construction of customized fetal growth curves (CCs).

METHOD

To determine if the new CCs, built excluding mothers with an abnormal weight, are better than standard CCs at identifying SGA. A total of 16,122 neonates were identified as SGA, LGA, or AGA, using the two models. Logistic regression and analysis of covariance were used to calculate the OR and CI for adverse outcomes by group. Gestational age was considered as a covariable.

RESULTS

The SGA rates by the new CCs and by the standard CCs were 11.8% and 9.7%, respectively. The SGA rate only by the new CCs was 18% and the SGA rate only by the standard CCs was 0.01%. Compared to AGA by both models, SGA by the new CCs had increased rates of cesarean section, (OR 1.53 (95% CI 1.19, 1.96)), prematurity (OR 2.84 (95% CI 2.09, 3.85)), NICU admission (OR 5.41 (95% CI 3.47, 8.43), and adverse outcomes (OR 1.76 (95% CI 1.06, 2.60). The strength of these associations decreased with gestational age.

CONCLUSION

The use of the new CCs allowed for a more accurate identification of SGA at risk of adverse perinatal outcomes as compared to the standard CCs.

Fasting Glucose for the Diagnosis of Gestational Diabetes Mellitus (GDM) during the COVID-19 Pandemic

Background: During the COVID-19 pandemic, different non-validated tests were proposed to simplify the diagnosis of gestational diabetes (GDM). Aim: To analyse the effects of replacing the two-step approach for Early-GDM and GDM diagnosis, with a fasting plasma glucose test. Material and Methods: This is a cohort study consisting of 3200 pregnant women: 400 with Early-GDM, 800 with GDM and 2000 with Non-GDM diagnosed using the two-step approach. Using fasting plasma glucose for Early-GDM and GDM diagnosis, according to the recommendations of Spain, Australia, Italy and the UK during the pandemic, the rates of missed and new Early-GDM and GDM were calculated and perinatal outcomes were analysed. Results: Using fasting plasma glucose in the first trimester >100 mg/dL for Early-GDM diagnosis, the rates of post-COVID missed and new Early-GDM were 79.5% and 3.2%, respectively. Using fasting plasma glucose at 24−28 weeks <84 or >92, 95 or 100 mg/dL for GDM diagnosis, the rates of missed GDM were 50.4%, 78%, 82.6% and 92.4%, respectively, and 8.6%, 5.6% and 2.3% women with Non-GDM were diagnosed with new GDM. Conclusion: Fasting plasma glucose is not a good test for the diagnosis of GDM either in the first trimester or at 24−28 weeks.