Evidence map›Paper›PMID 30994929›Full record

SynthesisAnnals of the New York Academy of Sciences2019

Maternal hemoglobin concentrations across pregnancy and maternal and child health: a systematic review and meta-analysis.

Melissa F Young, Brietta M Oaks, Sonia Tandon, Reynaldo Martorell, Kathryn G Dewey, Amanda S Wendt

Abstract readMeta-AnalysisSystematic Review
PubMed Full text at PMC Publisher
In one paragraph

Synthesis in Annals of the New York Academy of Sciences, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 152 papers, 12 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
152citing papers in PubMed, 12 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

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.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

152 citing papers in PubMed, 12 syntheses or guidelines pooled it.

  1. Clinical practice guideline "preconception care".Archives of gynecology and obstetrics · 2026
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  12. Prepartum Anemia and Risk of Postpartum Hemorrhage: A Meta-Analysis and Brief Review.Clinical and applied thrombosis/hemostasis : official journal of the International Academy of Clinical and Applied Thrombosis/Hemostasis
    Pooled it
  13. The impact of low-dose aspirin on hemoglobin levels in pregnancy: A secondary analysis of a randomized controlled trial for prevention of hypertensive disorders of pregnancy.International journal of gynaecology and obstetrics: the official organ of the International Federation of Gynaecology and Obstetrics · 2026
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92 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

Melissa F YoungHubert Department of Global Health, Emory University, Atlanta, Georgia.
Brietta M OaksDepartment of Nutrition and Food Sciences, University of Rhode Island, Kingston, Rhode Island.
Sonia TandonHubert Department of Global Health, Emory University, Atlanta, Georgia.
Reynaldo MartorellHubert Department of Global Health, Emory University, Atlanta, Georgia.
Kathryn G DeweyDepartment of Nutrition, University of California, Davis, Davis, California.
Amanda S WendtHeidelberg Institute of Global Health, University of Heidelberg, Heidelberg, Germany.

Funding

World Health Organization
6 · The paper itself

Abstract

Maternal anemia is a well-recognized global health problem; however, there remain questions on specific hemoglobin (Hb) thresholds that predict health risk or protection for mother and child. We conducted a systematic review and meta-analysis to examine the associations of maternal Hb concentrations with a range of maternal and infant health outcomes, accounting for the timing of measurement (preconception, and first, second, and third trimesters), etiology of anemia, and cutoff category. The systematic review included 272 studies and the meta-analysis included 95 studies. Low maternal Hb (<110 g/L) was associated with poor birth outcomes (low birth weight, preterm birth, small-for-gestational-age (SGA), stillbirth, and perinatal and neonatal mortality) and adverse maternal outcomes (postpartum hemorrhage, preeclampsia, and blood transfusion). High maternal Hb (>130 g/L) was associated with increased odds of SGA, stillbirth, preeclampsia, and gestational diabetes. Relationships varied by the timing of measurement and cutoff category (stronger associations with lower cutoffs); limited data were available on anemia etiology. There were insufficient data for other maternal outcomes and long-term child health outcomes. Current data are insufficient for determining if revisions to current Hb cutoffs are required. Pooled high-quality individual-level data analyses, as well as prospective cohort studies, would be valuable to inform the reevaluation of Hb cutoffs.

Indexed as

Child HealthFemaleHemoglobinsHumansInfant, Small for Gestational AgeMaternal HealthObstetric Labor ComplicationsPregnancyPregnancy ComplicationsPregnancy OutcomePremature BirthHemoglobinsanemiabirth outcomeshemoglobinpregnancyreview

Identifiers

PMID30994929
PMCPMC6767572

What OpenQuestion holds

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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.