Maternal haemoglobin concentrations before and during pregnancy as determinants of the concentrations of children at 3-5 years of age: A large follow-up study.

ABSTRACT

OBJECTIVE: To examine the association between haemoglobin (Hb) concentrations in mothers before and during pregnancy and those in children at 3-5 years of age. METHODS: The study included 78,923 women who conceived during 1993-1996 and delivered a singleton live infant. Maternal Hb concentrations were measured at pre-pregnancy health check-up and first prenatal visit, and during the second and third trimester. Hb concentrations of children born to these women were measured at 3-5 years of age. Associations between Hb levels in mothers and children were examined. Unconditional logistic regression was used to explore the association between maternal Hb levels and risk for anaemia in children. RESULTS: Maternal Hb levels before and during pregnancy were positively associated with children's Hb levels. Using maternal Hb ≥ 130 g/L as the referent, the risk for anaemia in children at 3-5 years of age was higher when maternal second trimester Hb concentrations were 70-99 g/L (odds ratio [OR] = 1.76, 95% confidence interval [CI] = 1.56-1.99), 100-109 g/L (OR = 1.45, 95% CI = 1.29-1.64), and 110-119 g/L (OR = 1.18, 95% CI = 1.04-1.33). Children were 1.52 and 1.23-times more likely to suffer from anaemia when maternal third trimester Hb concentrations were 70-99 and 100-109 g/L, respectively. A pre-pregnancy Hb concentration of 80-109 g/L and first prenatal visit Hb concentrations of 80-109 and 100-119 g/L were also associated with increased risks for childhood anaemia. CONCLUSION: Low maternal Hb concentrations before or during pregnancy increase the risk for anaemia in children at 3-5 years of age.