Evidence mapPaperPMID 39779258Full record

SynthesisBMJ open2025

Intrauterine metformin exposure and adiposity outcomes in children: a systematic review and meta-analysis.

Jennifer Fu, Najla Tabbara, George Tomlinson, Kellie E Murphy, Jill Hamilton, Denice S Feig

Abstract readSystematic ReviewMeta-Analysis
In one paragraph

Synthesis in BMJ open, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
4citing papers in PubMed, 1 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

4 citing papers in PubMed, 1 synthesis or guideline pooled it.

  1. Guideline
  2. Article
  3. Review
  4. Review
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.

Jennifer FuDepartment of Medicine, University of Toronto Faculty of Medicine, Toronto, Ontario, Canada.
Najla TabbaraPharmacy, Sinai Health System, Toronto, Ontario, Canada.
George TomlinsonDepartment of Medicine, University of Toronto Faculty of Medicine, Toronto, Ontario, Canada.
Kellie E MurphyObstetrics & Gynaecology, Sinai Health System, Toronto, Ontario, Canada.
Jill HamiltonDepartment of Pediatrics, University of Toronto, Toronto, Ontario, Canada.ORCID http://orcid.org/0000-0002-1958-2800
Denice S FeigDepartment of Medicine, University of Toronto Faculty of Medicine, Toronto, Ontario, Canada d.feig@utoronto.ca.ORCID http://orcid.org/0000-0001-8561-7584

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

objectiveThe study aims to assess the effect of intrauterine metformin exposure on offspring adiposity measures in childhood.

designSystematic review and meta-analysis. DATA SOURCES: Medline, Embase and Cochrane Central were searched from inception to 4 October 2024. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Follow-up studies of randomised-controlled trials and observational studies involving metformin use in pregnancy for any insulin-resistant maternal condition were included. DATA EXTRACTION AND SYNTHESIS: Two reviewers independently extracted data and completed risk-of-bias assessments using either Cochrane Risk-Of-Bias tool V.2 or Risk of Bias in Non-Randomised Studies of Exposure depending on study design. Meta-analyses were conducted using the generic inversed variance method in a random-effects model. Grading of Recommendations Assessment, Development and Evaluation methodology was used to assess certainty of evidence.

results18 studies reporting on 7975 children with metformin exposure in utero and over 1 million children without metformin exposure were included. At the oldest age of follow-up reported (weighted mean age of 4.4 years), children with metformin exposure for any maternal indication had comparable body mass index (BMI) with their non-exposed peers (standardised mean difference (SMD) -0.02; 95% CI: -0.11, 0.07; low certainty). When stratified by age at follow-up, while metformin-exposed children had slightly higher BMI at 1-3 years of age (SMD 0.15; 95% CI: 0.04, 0.27; low certainty), no difference remained between the two groups by ages 3-6 and 6-11 years. When stratified by maternal diagnosis, no difference in BMI was found in the diabetes and obesity subgroups, while in the polycystic ovary syndrome subgroup metformin-exposed children were heavier than non-exposed peers (SMD 0.31; 95% CI: 0, 0.62; low certainty). No difference was seen in overweight, obesity or waist circumference.

conclusionsMetformin-exposed children did not differ in adiposity measures compared with their non-exposed peers in later childhood. This adds to the growing body of evidence supporting the long-term safety of metformin use in pregnancy. PROSPERO REGISTRATION NUMBER: CRD42023394464.

Indexed as

AdiposityHypoglycemic AgentsMetforminPrenatal Exposure Delayed EffectsBody Mass IndexChildChild, PreschoolFemaleHumansPediatric ObesityPregnancyHypoglycemic AgentsMetforminDIABETES & ENDOCRINOLOGYDiabetes in pregnancyMeta-AnalysisObesityPregnancy

Identifiers

PMID39779258
PMCPMC11749820

What Socratic holds

Textmetadata
LicenceCC BY-NC
Read underepoch 390

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 Socratic graph.