Evidence map›Paper›PMID 29636978›Full record

ArticleBMJ open respiratory research2018

Maternal iron status during pregnancy and respiratory and atopic outcomes in the offspring: a Mendelian randomisation study.

Annabelle Bédard, Sarah J Lewis, Stephen Burgess, A John Henderson, Seif O Shaheen

Open access · goldAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in BMJ open respiratory research, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 23 papers, 4 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
23citing papers in PubMed, 4 pooled it
2.0field-weighted citation impact, top 14% of its field
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

23 citing papers in PubMed, 4 syntheses or guidelines pooled it, 29 citations in OpenAlex.

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  9. Zinc, Copper, and Iron in Selected Skin Diseases.International journal of molecular sciences · 2024
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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

5 authors at 4 institutions in 2 countries.

Annabelle BédardCentre for Primary Care and Public Health, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK.
Sarah J LewisPopulation Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK.
Stephen BurgessMRC Biostatistics Unit, University of Cambridge, Cambridge, UK.
A John HendersonPopulation Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK.
Seif O ShaheenCentre for Primary Care and Public Health, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK.
University of Bristol · GBPrimary Health Care · QAQueen Mary University of London · GBUniversity of Cambridge · GB

Funding

British Heart Foundation RG/13/13/30194Medical Research Council G0401540Medical Research Council G9815508Medical Research Council MC_UU_00002/7Medical Research Council MR/L003120/1Wellcome Trust 204623/Z/16/Z
6 · The paper itself

Abstract

introductionLimited evidence from birth cohort studies suggests that lower prenatal iron status may be a risk factor for childhood respiratory and atopic outcomes, but these observational findings may be confounded. Mendelian randomisation (MR) can potentially provide unconfounded estimates of causal effects by using common genetic variants as instrumental variables. We aimed to study the relationship between prenatal iron status and respiratory and atopic outcomes in the offspring using MR.

methodsIn the Avon Longitudinal Study of Parents and Children birth cohort, we constructed four maternal genotypic risk scores by summing the total number of risk alleles (associated with lower iron status) across single nucleotide polymorphisms known to be associated with at least one of four iron biomarkers (serum iron, ferritin, transferrin and transferrin saturation). We used MR to study their associations with respiratory and atopic outcomes in children aged 7-9 years (n=6002).

resultsWhen analyses were restricted to mothers without iron supplementation during late pregnancy, negative associations were found between the maternal transferrin saturation score and childhood forced expiratory volume in 1 s and forced vital capacity (difference in age, height and gender-adjusted SD units per SD increase in genotypic score: -0.05 (-0.09, -0.01) p=0.03, and -0.04 (-0.08, 0.00) p=0.04, respectively).

conclusionUsing MR we have found weak evidence suggesting that low maternal iron status during pregnancy may cause impaired childhood lung function.

Indexed as

ALSPACironlung functionMendelian randomisationpregnancy

Identifiers

PMID29636978
PMCPMC5890059
OpenAlexW2794859342

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Registered trials

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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.