Prenatal Hemoglobin Levels and Early Cognitive and Motor Functions of One-Year-Old Children

Abstract

Objective: To explore the relationship between prenatal hemoglobin (Hb) concentration and infant cognitive and motor functions.

Methods: Our prospective cohort study included 1-year-old children born to women enrolled at their first antenatal care (ANC) visit in Allada, Benin, before 29 weeks of pregnancy, within a trial comparing the efficacy of sulfadoxine-pyrimethamine and mefloquine. Hb concentrations of pregnant women were determined from venous blood samples collected at first and second ANC visits of at least 1-month interval and at delivery. Women were prescribed oral iron, folic acid, and anthelminthics after the first ANC visit. A total of 636 children (76.8% of eligible children) were assessed by trained research nurses for cognitive and motor functions by using the Mullen Scales of Early Learning.

Results: Prevalence of anemia (Hb < 110 g/L) decreased from 67.0% at first ANC visit (mean gestational age [SD], 22.1 [4.0] weeks) to 38.4% at delivery. Mean (SD) Hb concentrations increased from 103.7 (12.3) at first ANC visit to 112.4 (14.1) at delivery. We observed a significant negative quadratic relationship between infant gross motor (GM) function and Hb concentration at first and second ANC visits. Thus, infant GM scores increased sharply with increasing maternal Hb concentration until 90 g/L where increasing GM was mild, and began to decline after 110 g/L.

Conclusions: There appears to be an Hb concentration range that may be optimal for GM function of 1-year-old children. This may reflect the importance of physiologic hemodilution, which occurs after the second trimester until 34 weeks of gestation.

Trial registration: ClinicalTrials.gov NCT00811421.

Conflict of interest statement

FINANCIAL DISCLOSURE: The authors have indicated they have no financial relationships relevant to this article to disclose.

Copyright © 2015 by the American Academy of Pediatrics.

Figures

FIGURE 1

Relationship between Hb concentration at first ANC visit and infant GM scores. The solid line indicates the fitted model, whereas the dash lines represent 95% CIs.

FIGURE 2

Relationship between Hb concentration at second ANC visit and infant GM scores. The solid line indicates the fitted model, whereas the dash lines represent 95% CIs.