Discussion
anemia
PRETERM BIRTH, IRON DEFICIENCY, ANEMIA
We find that maternal preconception Hb concentration was positively associated with offspring Hb concentrations during the first 2 y of life. In contrast, associations between maternal preconception Hb and anemia and child development during 1Our null findings on maternal preconception Hb concentration and birth outcomes contrast with earlier findings in a systematic review where preconception anemia was associated with an increased risk of low birthweight (OR 1.72; 95% CI: 1.31–2.26) and SGA births (OR 1.79; 95% CI: 1.39–2.31) [In our cohort, we present novel data on the association of maternal preconception Hb concentration and child Hb concentration across the first 2 y of life. Women who are anemic and/or iron deficient before conception are also at increased risk of getting worse during pregnancy because of the high physiologic demands of pregnancy [We report significant associations with maternal preconception Hb concentration on child motor development in the first y of life, particularly in low home environments, but no long-term associations at 24 mo. We also report associations between maternal preconception anemia and child cognition and language development at 24 mo, which were stronger in high home environments for the latter. The rationale for mixed findings on home environment is unclear and merits further examination. It is possible this is because of different mechanisms, as the role of stimulation may vary by child age and outcomes, but it could also be due to chance and recommend caution in interpterion given multiple testing. Periconceptional nutrition may influence early childhood development by affecting the growth and development of key organs, such as the brain, liver, and pancreas, during the first few weeks of pregnancy [Our study provides novel insight into the importance of maternal anemia during the preconception period and child health and development. This is one the largest prospective studies to date to examine the role of maternal preconception nutrition on long-term child health outcomes. A key strength of this work is the prospective design and the low rates of attrition (<10%) over the past decade. Our design and high-quality data collection allowed for accurate estimation of gestational age and, thus, calculation of key birth outcome variables such as preterm birth and SGA [In summary, maternal preconception Hb concentration was associated with child Hb concentrations across the first 1000 d. Modest associations with maternal preconception Hb concentration and anemia and child development in early life merit further examination. However, in this cohort from Vietnam, preconception Hb concentration was not a significant predictor of birth outcomes or long-term child development. Our findings support the need to revisit the use of measuring Hb concentration in women of reproductive age to predict later risk of adverse outcomes, and more research is needed in settings with a greater burden of anemia and iron deficiency as we support programs and policies to expand maternal anemia reduction programs to the adolescent and preconception periods.