SynthesisJournal of epidemiology2026
Impact of Maternal Underweight on Infant and Maternal Outcomes in Japanese Women: A Systematic Review and Meta-analysis.
Synthesis in Journal of epidemiology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
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Who cites it
2 citing papers in PubMed.
- Reconsidering the Perinatal Risks of Maternal Underweight in Japan.Journal of epidemiology · 2026Article
- Response to "Reconsidering the Perinatal Risks of Maternal Underweight in Japan".Journal of epidemiology · 2026Article
Corrections and comments
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Authors and funding
4 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundPre-pregnancy underweight (BMI <18.5 kg/m
methodsWe conducted a systematic review and meta-analysis following Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. MEDLINE, EMBASE, CINAHL, PsycINFO, Cochrane Library, and Ichushi were searched from inception to February 2024. Cohort and case-control studies examining associations between pre-pregnancy underweight and perinatal outcomes in Japanese women with singleton pregnancies were included. Primary outcomes were low birth weight (LBW), small for gestational age (SGA), and preterm birth (PTB). Random-effects models calculated pooled odds ratios (ORs) with 95% confidence intervals (CIs).
resultsThirty-four studies were analyzed. Pre-pregnancy underweight significantly increased risks of LBW (OR 1.61; 95% CI, 1.38-1.86), SGA (OR 1.59; 95% CI, 1.55-1.63), and PTB (OR 1.23; 95% CI, 1.19-1.26). Mean birth weight was 115.02 g lower (95% CI, -128.05 to -101.99) in underweight mothers.
conclusionPre-pregnancy underweight among Japanese women is significantly associated with increased risks of adverse perinatal outcomes. Notably, these elevated risks persist despite the high background prevalence of underweight, suggesting that their adverse effects are not diminished in populations where it is more common. These findings underscore the importance of increasing awareness of preconception care and emphasize the need to optimize pre-pregnancy weight.
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Registered trials
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