Evidence map›Paper›PMID 40436448›Full record

ArticleBMJ open2025

Maternal periconception serum vitamin B12 concentration and risk of preterm birth: a prospective cohort study.

Yuanzhou Peng, Yi Zhang, Xiaotian Chen, Yalan Dou, Jun Huang, Xiaohua Zhang, Guoying Huang, Xiangfeng Lu, Weili Yan

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PubMed Full text at PMC Publisher
In one paragraph

Article in BMJ open, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–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

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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

1 citing paper in PubMed.

  1. Article
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

9 authors.

Yuanzhou PengResearch Unit of Early Intervention of Genetically Related Childhood Cardiovascular Diseases (2018RU002), Chinese Academy of Medical Sciences & Peking Union Medical College, Shanghai, China.
Yi ZhangDepartment of Clinical Epidemiology and Clinical Trial Unit, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China.
Xiaotian ChenDepartment of Clinical Epidemiology and Clinical Trial Unit, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China.
Yalan DouDepartment of Clinical Epidemiology and Clinical Trial Unit, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China.
Jun HuangMinhang Maternal and Child Health Hospital, Shanghai, China.
Xiaohua ZhangMinhang Maternal and Child Health Hospital, Shanghai, China.
Guoying HuangResearch Unit of Early Intervention of Genetically Related Childhood Cardiovascular Diseases (2018RU002), Chinese Academy of Medical Sciences & Peking Union Medical College, Shanghai, China yanwl@fudan.edu.cn gyhuang@shmu.edu.cn luxf@pumc.edu.cn.
Xiangfeng LuKey Laboratory of Cardiovascular Epidemiology & Department of Epidemiology, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China yanwl@fudan.edu.cn gyhuang@shmu.edu.cn luxf@pumc.edu.cn.
Weili YanResearch Unit of Early Intervention of Genetically Related Childhood Cardiovascular Diseases (2018RU002), Chinese Academy of Medical Sciences & Peking Union Medical College, Shanghai, China yanwl@fudan.edu.cn gyhuang@shmu.edu.cn luxf@pumc.edu.cn.ORCID http://orcid.org/0000-0002-7633-7449

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundMaternal vitamin B12 levels during pregnancy have been implicated in the risk of preterm birth, but current evidence remains controversial and just focuses on measurements during pregnancy.

objectiveTo assess the association of maternal periconception serum vitamin B12 concentration, including levels before conception and at early gestation, with the risk of preterm birth and its subtypes in a large Chinese population.

designProspective cohort study.

participantsA total of 26 977 women from Shanghai, China, with serum vitamin B12 concentration measured either before conception or at early gestation. OUTCOME MEASURES: Preterm birth was defined as delivery before 37 weeks of gestation and was stratified as preterm birth <32 and <34 weeks. Cox regression was used to estimate the association between maternal vitamin B12 and preterm birth.

resultsOverall, 1599 (5.9%) of participants delivered preterm. The median periconception vitamin B12 concentration was 483.0 (IQR, 368.0-622.0) pg/mL. No evidence was observed of an association between maternal vitamin B12 concentration and risk of preterm birth (per 100 pg/mL increment: adjusted hazard ratio (aHR), 0.99; 95% CI, 0.96 to 1.02,

conclusionsNo evidence of associations was found between maternal vitamin B12 concentration and risk of preterm birth in a population with relatively sufficient vitamin B12 levels. Future studies in populations with varied baseline levels of vitamin B12 are needed to validate these findings across different populations and regions.

Indexed as

Premature BirthVitamin B 12AdultChinaFemaleGestational AgeHumansInfant, NewbornPregnancyProportional Hazards ModelsProspective StudiesRisk FactorsYoung AdultVitamin B 12NUTRITION & DIETETICSObservational StudyPregnancyPregnant WomenPUBLIC HEALTH

Identifiers

PMID40436448
PMCPMC12121574

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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.