Neonatal outcomes impacted by weight gain during gestational diabetes

Neonatal outcomes impacted by weight gain during gestational diabetes | Image Credit: © interstid - © interstid - stock.adobe.com.

According to a recent study published in China CDC Weekly, there is a positive association between weekly gestational weight gain (GWG) after gestational diabetes mellitus (GDM) diagnosis and large for gestational age (LGA) and macrosomia risks.

Intrauterine development and maternal health are often indicated by neonatal weight, with excessive GWG during pregnancy linked to increased LGA and macrosomia risks among women diagnosed with GDM. However, it is unclear how weekly GWG in these women impacts fetal birth weight.

To determine the association between weekly GWG during pregnancy after GDM diagnosis and LGA and macrosomia risks, investigators conducted a retrospective study using data from 7 regional tertiary hospitals in China. Associations were determined using odds ratios (ORs) and confidence intervals (CIs).

LGA was defined as a birth weight above the 90th percentile for an infant’s sex and gestational age. Macrosomia was defined as a birth weight greater than 4000 g. Body mass index (BMI) was divided into 9 intervals, with LGA and macrosomia rates measured in each interval.

The medical records of female patients with GDM from 2011 to 2021 were gathered, with patient weight recorded a week before or after the activity. Data extracted from medical records included maternal age, weight before pregnancy, week of GDM diagnosis, weight at GDM diagnosis, weight before delivery, weeks remaining before delivery, and neonatal birth weight.

Pre-pregnancy weight was self-reported by participants, and this data was used to calculate pre-pregnancy BMI. Weight at GDM diagnosis was determined as the reported weight in the week before or after undergoing the 75-g oral glucose tolerance test.

There were 11,168 women with a GDM diagnosis included in the analysis, with a mean maternal age of 31.02 years. LGA infants were seen from 11.98% of participants and infants with macrosomia from 6.84%.

The OR for fetal growth significantly increased when categorized by normal weight, with adjusted ORs for LGA and macrosomia of 2.641 and 3.299 respectively at CIs of 95%. The overweight and obese groups also had increased ORs. Weight at GDM diagnosis was directly correlated with LGA and macrosomia risks.

Data from the analysis indicated the risk of LGA increases from 1.33% in patients with a BMI of under 19 kg/m2 at GDM diagnosis to 24.71% in patients with a BMI of 33 kg/m2 or above at GDM diagnosis. The risk of macrosomia also increases from 1.33% to 15.21% respectively.

These results indicated a direct association between GWG at GDM diagnosis and risks of LGA and macrosomia. This association was found in all BMI groups. Investigators recommended strengthened regulation on weekly GWG for women diagnosed with GDM.

Reference

Liu N, Lyu J, Wang H, et al. Gestational diabetes mellitus and neonatal birth weight - China, 2011-2021. China CDC Wkly. 2023;5(32):703-709. doi:10.46234/ccdcw2023.135