Is HbA1c associated with birth weight? A multivariable analysis of Pakistani pregnant women

Aim: Globally, one in seven infants is born with low birth weight and 3%–7% of infants are born with high birth weight, with the greatest burden noted in low- and middle-income countries. This study investigated the association between maternal prenatal glucose regulation and birth weight and the moderating effect of fetal sex among Pakistani women. Methods: Secondary data from a prospective longitudinal study of healthy pregnant women from Pakistan (N = 189) was used. Participants provided a blood sample (12–19 weeks' gestational age) for the assessment of HbA1c (%). Birth weight (g) was collected following delivery. Results: Higher maternal HbA1c was associated with higher birth weight (b = 181.81, t[189] = 2.15, p = 0.03), which was moderated by fetal sex (b = −326.27, t[189] = −2.47, p = 0.02), after adjusting for gestational age at birth, ethnicity, and pregnancy weight. Among women carrying a male fetus, every 1% increase in HbA1c predicted a 182 g increase in birth weight (b = 181.81, t[189] = 2.15, p = 0.03). Conclusions: Results extend research from high-income countries and indicate that fetal sex may have implications for glucose regulation in early to mid-pregnancy. Future research should examine sociocultural factors, which could elucidate potential mediating factors in the relation between HbA1c and birth weight in healthy pregnancies.