Maternal Hemoglobin Concentration during Gestation and Risk of Anemia in Infancy: Secondary Analysis of a Randomized Controlled Trial

Objective This study examined the relationship between maternal hemoglobin (Hb) concentration and the risk of anemia in infancy. Study design This analysis included 17 193 women who entered the trial when they were >= 20 years of age, no more than 20 weeks of gestation, had mild or no anemia, and delivered singleton live births. Maternal Hb concentrations were measured in the first trimester and during 24-28 weeks of gestation; infant Hb concentrations were measured at 5-7 months and 11-13 months of life. The associations between maternal Hb concentrations and infant Hb concentrations were examined. Results Maternal Hb concentrations measured during 24-28 weeks of gestation, but not in the first trimester, were correlated with infant Hb concentrations measured at either of the 2 post-partum periods. The risk of infant anemia at 5-7 months of age increased when maternal Hb concentration was <= 109 g/L during 24-28 weeks of gestation (aOR, 1.95; 95% CI, 1.59-2.40) and 11-13 months of age (aOR, 1.72; 95% CI, 1.36-2.18), whereas the risk of anemia during 5-7 months of age as well as 11-13 months in infancy decreased when maternal Hb level at 24-28 weeks of gestation was 120-129 g/L (aOR for 5-7 months, 0.74 [95% CI, 0.64-0.85]; aOR for 11-13 months, 0.72 [95% CI, 0.61-0.85]), or >= 130 g/L (aOR for 5-7 months, 0.75 [95% CI, 0.63-0.90]; aOR for 11-13 months, 0.89 [95% CI, 0.73-1.08]). Conclusions Low maternal Hb concentration during 24-28 weeks of gestation was associated with an increased risk of anemia in infancy, whereas high maternal Hb concentration was associated with a reduced risk of anemia.