Division of Infectious Diseases and International Health, University of Virginia School of Medicine, Charlottesville, Virginia.
The International Center for Diarrhoeal Disease and Research, Dhaka, Bangladesh.
Am J Trop Med Hyg. 2021 Nov 29;106(2):424-431. doi: 10.4269/ajtmh.21-0268.
Low birth weight (LBW) is associated with a higher risk of neonatal mortality and the development of adult-onset chronic disease. Understanding the ongoing contribution of maternal hemoglobin (Hgb) levels to the incidence of LBW in South Asia is crucial to achieve the World Health Assembly global nutrition target of a 30% reduction in LBW by 2025. We enrolled pregnant women from the rural Tangail District of Bangladesh in a Maternal Newborn Health Registry established under The Global Network for Women's and Children's Health Research. We measured the Hgb of pregnant women at enrollment and birth weights of all infants born after 20 weeks gestation. Using logistic regression to adjust for multiple potential confounders, we estimated the association between maternal Hgb and the risk of LBW. We obtained Hgb measurements and birth weights from 1,665 mother-child dyads between July 2019 and April 2020. Using trimester-specific cutoffs for anemia, 48.3% of the women were anemic and the mean (±SD) Hgb level was 10.6 (±1.24) g/dL. We identified a U-shaped relationship where the highest risk of LBW was seen at very low (< 7.0 g/dL, OR = 2.00, 95% CI = 0.43-7.01, P = 0.31) and high (> 13.0 g/dL, OR = 2.17, 95% CI = 1.01-4.38, P = 0.036) Hgb levels. The mechanisms underlying this U-shaped association may include decreased plasma expansion during pregnancy and/or iron dysregulation resulting in placental disease. Further research is needed to explain the observed U-shaped relationship, to guide iron supplementation in pregnancy and to minimize the risk of LBW outcomes.
低出生体重（LBW）与新生儿死亡率升高和成年后慢性疾病的发生风险增加有关。了解南亚地区孕产妇血红蛋白（Hgb）水平对 LBW 发生率的持续影响，对于实现世界卫生大会到 2025 年将 LBW 降低 30%的全球营养目标至关重要。我们在孟加拉国农村的 Tangail 区招募了参加母婴健康登记的孕妇，该登记是在全球妇女儿童健康研究网络下建立的。我们在孕妇登记时测量了 Hgb，以及所有在 20 周妊娠后出生的婴儿的出生体重。我们使用逻辑回归来调整多个潜在混杂因素，估计了孕产妇 Hgb 与 LBW 风险之间的关系。我们在 2019 年 7 月至 2020 年 4 月期间获得了 1665 对母婴对的 Hgb 测量值和出生体重。使用贫血的特定孕期截断值，48.3%的女性贫血，平均（±SD）Hgb 水平为 10.6（±1.24）g/dL。我们发现了一种 U 形关系，其中极低（<7.0 g/dL，OR=2.00，95%CI=0.43-7.01，P=0.31）和高（>13.0 g/dL，OR=2.17，95%CI=1.01-4.38，P=0.036）Hgb 水平与 LBW 的风险最高。这种 U 形关系的潜在机制可能包括怀孕期间血浆扩张减少和/或铁调节异常导致胎盘疾病。需要进一步研究来解释观察到的 U 形关系，以指导妊娠期间的铁补充，并最大限度地降低 LBW 结局的风险。
