Preconception Hemoglobin Concentration and Risk of Low Birth Weight and Small-for-Gestational-Age: A Large Prospective Cohort Study in China.

Xiaojing Liu,Rongwei Ye,Hongtian Li,Nan Li,Yali Zhang,Hang An,Zhiwen Li,Le Zhang,Jianmeng Liu

doi:10.3390/nu14020271

Abstract

Less is known about the impact of maternal preconception anemia on birth outcomes. We aimed to examine associations between preconception hemoglobin (Hb) concentrations with risk of low birth weight (LBW) and small-for-gestational-age (SGA). This study was from a large population-based prospective cohort in China and included 124,725 women with singleton live births delivered at gestational ages of 28–45 weeks who were registered before pregnancy. Maternal Hb concentrations were measured during registration, and other health-related information was recorded prospectively. Logistic regression was used to evaluate the associations between preconception Hb concentrations with risk of LBW and SGA, adjusting for potential confounders. The results showed women with preconception anemia accounted for 22.28%. The incidences of LBW/SGA were 2.37%/6.30% among anemic women, and 2.01%/5.48% among non-anemic women, respectively. Preconception mild anemia increased by 17% (95% confidence interval (CI): 1.06, 1.28) and 14% (95% CI: 1.07, 1.21) the risk for LBW and SGA, while moderate-to-severe anemia had no significant association with LBW and SGA. Compared with the 120–129 g/L group, a U-shaped association was observed between preconception Hb concentrations with LBW and SGA. In conclusion, not only maternal anemia but also elevated Hb concentrations before pregnancy contribute to an increased risk of LBW and SGA.

Highlights

Anemia is a severe public health problem, especially in developing countries [1]
We investigated whether anemia prior to pregnancy has any impact on the risk of Low birth weight (LBW) and SGA with a large historical prospective cohort of reproductive-aged women in rural China
Our results demonstrated that preconception anemia significantly increased infants in terms of LBW and SGA status, and the effects were evident in women who were mildly anemic prior to pregnancy

Summary

Introduction

Anemia is a severe public health problem, especially in developing countries [1]. 29% of non-pregnant women are anemic, while the rate rises to 38% after pregnancy as a result of an inequal expansion of the plasma volume and red cells [2]. An important indicator of malnutrition status, is considered as a risk factor for various pregnancy complications threatening both the mothers’ and infants’ health [3,4,5]. Low birth weight (LBW), a proxy for assessing intrauterine fetus malnutrition and growth retardation, is associated with neonatal mortality and morbidity, and even longterm health status into adulthood [6,7,8].

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