Women with moderate anaemia prior to conception benefited most from nutrition interventions: a secondary analysis of the Women First preconception maternal nutrition trial

TL;DR

Women with moderate anemia before pregnancy benefited most from nutrition supplements, especially when taken early.

Contribution

Identified that women with moderate pre-pregnancy anemia gained the most from early nutrition interventions.

Findings

Women with Hb 90–99 g/L had the greatest improvement in birth weight, length, and head circumference with early supplementation.

Early supplementation (Arm 1) showed significant benefits for women with Hb 100–109 g/L in birth weight.

Late supplementation (Arm 2) showed modest benefits for women with Hb 90–99 g/L in birth weight.

Abstract

The Women First (WF) Preconception Maternal Nutrition trial found greater benefits of small-quantity lipid-based nutrient supplements (SQ-LNS) for intrauterine growth among anaemic versus non-anaemic women at preconception. We investigated whether the benefits of SQ-LNS in improving markers of intrauterine growth occurred evenly across the mild to moderate spectrum of pre-pregnancy anaemia.

We analysed WF data (n=2443 maternal-newborn dyads) from Pakistan, India, Guatemala and the Democratic Republic of Congo. Women received SQ-LNS either ≥3 months preconception through pregnancy (Arm 1); starting in the late first trimester (Arm 2); or not at all (Arm 3: control), with all supplementations discontinued at delivery. The outcomes were infant weight, length and head circumference measured within 48 hours of birth, expressed as Z-scores. For each site, adjusted mean differences in the Z-scores were computed across six pre-pregnancy haemoglobin (Hb) categories (80–89, 90–99, 100–109, 110–119, 120–129, and ≥130 g/L) and pooled using meta-analysis.

The effect of SQ-LNS on birth weight, length and head circumference varied by pre-pregnancy Hb categories. No significant differences in pooled mean Z-scores were observed for any Hb category >110 g/L, and no differences were found for Arm 1 vs Arm 2 across any Hb categories. For women with Hb 90–99 g/L pooled mean differences (95% CI) in the Z-scores for length (0.60 (0.03 to 1.23)), weight (0.50 (0.11 to 0.89)) and head circumference (0.26 (0.02 to 0.51)) were greatest for Arm 1 versus Arm 3. For women with Hb 100–109 g/L in Arm 1 versus Arm 3, pooled mean difference (95% CI) in birth weight Z-scores was significantly greater (0.33 (0.24 to 0.42)). Arm 2 vs Arm 3 women with Hb 90–99 g/L had greater birth weight Z-scores (0.14 (0.05 to 0.22)).

The findings highlight the importance of identifying women preconception for whom nutrition interventions may have the greatest impact on fetal growth.

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