Maternal fasting time over 9 to 10 hours before delivery increases risk of neonatal hypoglycemia

The researchers, therefore, suggest that prenatal management should consider not only maternal safety but also the prevention of neonatal hypoglycemia.

Neonatal hypoglycemia is defined as plasma glucose level below 30 mg/dL (1.65 mmol/L) in the first 24 hours of life and less than 45 mg/dL (2.5 mmol/L) thereafter. It is the most common metabolic problem in newborns. Major long-term sequelae include neurologic damage resulting in mental retardation, developmental delay, recurrent seizure activity, and personality disorders. Some evidence indicates that severe hypoglycemia may impair cardiovascular function.

The prospective single-centre cohort study was undertaken by Takeyuki Kiguchi, Kyoto University School of Public Health, Kyoto, Japan, and colleagues to evaluate the association between maternal fasting time before delivery and the occurrence of hypoglycemia in neonates immediately after birth.

The study included pregnant women who delivered at the study institution between 2021 and 2023 and their neonates. The primary outcome of the study was determined as the incidence of neonatal hypoglycemia after birth, defined as a blood glucose level below 47 mg/dL. Fasting time was categorized into quartiles, and an association between maternal fasting time and neonatal hypoglycemia was determined. Logistic regression analysis was used to calculate crude or adjusted odds ratios of maternal fasting time for neonatal hypoglycemia. The study included 663 pregnant women and 696 neonates.

Based on the study, the researchers reported the following findings:

• Compared with the reference group with a short fasting time of 4.3 h or less, the adjusted odds ratios for neonatal hypoglycemia were 1.47 for middle fasting time (4.3–9.8 h), 4.05 for long fasting time (9.8–14.6 h), and 4.99 for very long fasting time (>14.6 h).
• In the subgroup analysis, the association between maternal fasting time and neonatal hypoglycemia showed different trends according to the mode of delivery.

"Maternal fasting time over 9–10 hours before delivery was linked with the occurrence of neonatal hypoglycemia," the researchers wrote. "Obstetrical management is required that considers not only maternal safety but also neonatal hypoglycemia prevention."

Reference:

Makino, Y., Kiguchi, T., Hayashi, K., Kato, N., Ueda, K., Tanaka, T., & Iwami, T. Association between pregnant women fasting duration and neonatal hypoglycemia: A prospective cohort study. International Journal of Gynecology & Obstetrics. https://doi.org/10.1002/ijgo.15228