Association between Maternal Blood Glucose Levels during Pregnancy and Birth Outcomes: A Birth Cohort Study

This study aimed to investigate the relationship between maternal blood glucose levels during pregnancy and neonatal birth outcomes in Northwest China.

This population-based cohort study included 10,010 first-trimester pregnant women who joined the birth cohort of the Northwest Women's and Children's Hospital from July 2018 to July 2020. Basic demographic characteristics, lifestyle and behavior patterns were collected. Oral glucose tolerance test (OGTT) results during the second trimester and pregnancy outcomes after childbirth were also collected. A generalized linear model was constructed to analyze the effects of blood glucose levels on neonatal birth outcomes.

We found that every 1 mmol/L increase in fasting plasma glucose (FPG) was associated with an increase in birth weight (β = 100.22 g, 95% confidence interval (95%CI): 81.91, 118.52), birth weight Z score (β = 0.23, 95%CI: 0.19, 0.27) and birth weight Z centile (β = 6.72%, 95%CI: 5.51, 7.94). Moreover, the risk of macrosomia, premature birth and being born large for gestational age (LGA) increased by 2.01 (95%CI: 1.67, 2.43), 1.35 (95%CI: 1.09, 1.66) and 1.80 (95%CI: 1.57, 2.07) times, respectively. Additionally, for every 1 mmol/L increase in FPG associated with a decrease in gestational age (β = -0.12 weeks, 95%CI: -0.19, -0.06), the risk of SGA decreased by 0.70 (OR = 0.70, 95%CI: 0.55, 0.89) times. Every 1 mmol/L increase in 1/2-h PG had similar outcomes as FPG, besides premature birth and SGA.

Higher blood glucose in pregnant women may increase neonatal birth weight, decrease gestational age and lead to a higher risk of macrosomia, premature birth and LGA. Mothers should actively prevent and control hyperglycemia to promote maternal and infant health.