Low Blood Sugar Before Pregnancy May Raise Risk of Preterm Birth, Low Birth Weight: Study Finds

The analysis found that women with hypoglycemia before pregnancy were more likely to experience adverse outcomes such as preterm birth, low birth weight, and birth defects. These women were generally younger and more likely to fall into the underweight BMI category. Interestingly, the impact of hypoglycemia varied with BMI: underweight women faced a higher risk of miscarriage, while overweight women had a reduced risk of delivering a baby large for gestational age.

The authors state, “In addition to paying attention to women with preconception hyperglycemia, our findings call for increased concern for women with hypoglycemia in preconception glycemic screening. These findings emphasize the importance of preconception examination in preventing and managing reproductive health risks for all women planning to conceive, and also highlight the necessity of comprehensive screening and coordinated interventions for abnormal FPG (fasting plasma glucose) prior to and during pregnancy, which is crucial for advancing the intervention window and mitigating the risk of adverse pregnancy outcomes.”

Reference: u H, Yang Y, Zhao C, Lyu X, Li J, Lei J, et al. (2025) Preconception hypoglycemia and adverse pregnancy outcomes in Chinese women aged 20–49 years: A retrospective cohort study in China. PLoS Med 22(7): e1004667. https://doi.org/10.1371/journal.pmed.1004667