Skip to content
DraconiticResearch
Search Sources API
203,203 studies31 sourcesUpdated 15 min ago
Peer-reviewedCC BYJournal of global health

Associations between month/season of birth and health outcomes: an umbrella review of systematic reviews and meta-analyses.

  • Zhuoya Zhang1
  • Lin Wang1,2
  • Yinghui Zhou1
  • Jie Zhang1
  • Cheng Tan1
  1. 1Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Chinese Medicine, Nanjing, China.
  2. 2Yancheng TCM Hospital Affiliated to Nanjing University of Chinese Medicine, Yancheng, Jiangsu, China.
Read full textPDFDOICite

Abstract

Background

The relationship between month or season of birth and long-term health outcomes remains an important but underexplored topic in public health. Evidence suggests that birth timing may influence disease susceptibility and broader health trajectories, reflecting interactions between biological and ecological factors. Clarifying these associations is essential for advancing prevention and a holistic view of health shaped by temporal exposures.Methods

We conducted an umbrella review of systematic reviews and meta-analyses indexed in PubMed, Embase, and Web of Science up to 2 July 2025. Eligible studies reported quantitative estimates for associations between birth month/season and objectively measured health outcomes. We used random-effects models to produce pooled estimates and evaluated heterogeneity, small-study effects, and bias. We graded associations using established class-of-evidence criteria and assessed methodological quality with AMSTAR 2.Results

We included 10 meta-analyses, comprising 614 unique associations (defined as individual pairwise analyses between a specific birth month/season exposure and a distinct health outcome). Of these, 45 associations were statistically significant, and 25 were eligible for evidence grading. No association met class I criteria, but one (January birth and schizophrenia) reached class II. The most consistent findings involved neurodevelopmental and psychiatric outcomes, with winter births linked to a modest increase in schizophrenia risk (odds ratio (OR) = 1.05) and spring births to multiple sclerosis. Most autoimmune, oncological, and perinatal associations were graded as weak (class III-IV) due to small effect sizes or heterogeneity.Conclusions

The strongest evidence for associations between month/season of birth and long-term health outcomes was restricted to specific neuropsychiatric outcomes, with most other associations graded as weak. Grading the credibility of these associations helps distinguish robust signals from exploratory findings, and provides a clear framework for future mechanistic and epidemiological investigations.Registration

PROSPERO: CRD420251110595.

Related

  1. Prenatal antiseizure medication exposure and offspring structural and neurodevelopmental outcomes: an umbrella review of systematic reviews and meta-analyses
    Yulong Li, Yutong Fu, Yifei Duan +4
    BMC Pregnancy and ChildbirthPeer-reviewedCC BY-NC-ND 4.0Full textObstetrics, gynaecology & paediatricsPMC
  2. Dietary and lifestyle quality and endometrial cancer: Incidence and survivorship outcomes—An umbrella review of systematic reviews and meta-analyses
    Ruqaiya Al Ramadhani, Newshaw Arvin, Saphy Moussa +3
    PLOS OnePeer-reviewedCC BY 4.0Full textEpidemiology & public healthNutritionPLOS
  3. Risk factors for renal cell carcinoma: An umbrella review of systematic reviews and meta-analyses
    Sihan Chen, Yin Huang, Bo Chen +9
    BMC MedicinePeer-reviewedCC BY 4.0General medicineCrossref
  4. Evidence quality assessment of traditional Chinese medicine and integrated traditional Chinese and Western medicine for acute upper respiratory infection in children: an umbrella review of systematic reviews and meta-analyses
    Zhen Liu, Yumeng Yang, Yuetong Liu +4
    Frontiers in pediatricsPeer-reviewedCC BYFull textGeneral medicineEurope PMC
  5. Factors associated with mortality in patients with atrial fibrillation: an umbrella review of systematic reviews and meta-analyses
    Jin Luo, Yunpu Niu, Ming Ni +2
    Frontiers in Cardiovascular MedicinePeer-reviewedCC BY 4.0Full textCardiovascular medicineCrossrefPMC

Cite

BibTeXRIS
BibTeX
@article{zhang2026associations,
  title = {{Associations between month/season of birth and health outcomes: an umbrella review of systematic reviews and meta-analyses.}},
  author = {Zhuoya Zhang and Lin Wang and Yinghui Zhou and Jie Zhang and Cheng Tan},
  journal = {Journal of global health},
  year = {2026},
  month = oct,
  doi = {10.7189/jogh.16.04234},
  url = {https://europepmc.org/article/MED/42852613},
  note = {CC BY},
}
RIS
TY  - JOUR
TI  - Associations between month/season of birth and health outcomes: an umbrella review of systematic reviews and meta-analyses.
AU  - Zhuoya Zhang
AU  - Lin Wang
AU  - Yinghui Zhou
AU  - Jie Zhang
AU  - Cheng Tan
PY  - 2026
DA  - 2026/10/09
JO  - Journal of global health
DO  - 10.7189/jogh.16.04234
UR  - https://europepmc.org/article/MED/42852613
AB  - Background  The relationship between month or season of birth and long-term health outcomes remains an important but underexplored topic in public health. Evidence suggests that birth timing may influence disease susceptibility and broader health trajectories, reflecting interactions between biological and ecological factors. Clarifying these associations is essential for advancing prevention and a holistic view of health shaped by temporal exposures.Methods  We conducted an umbrella review of systematic reviews and meta-analyses indexed in PubMed, Embase, and Web of Science up to 2 July 2025. Eligible studies reported quantitative estimates for associations between birth month/season and objectively measured health outcomes. We used random-effects models to produce pooled estimates and evaluated heterogeneity, small-study effects, and bias. We graded associations using established class-of-evidence criteria and assessed methodological quality with AMSTAR 2.Results  We included 10 meta-analyses, comprising 614 unique associations (defined as individual pairwise analyses between a specific birth month/season exposure and a distinct health outcome). Of these, 45 associations were statistically significant, and 25 were eligible for evidence grading. No association met class I criteria, but one (January birth and schizophrenia) reached class II. The most consistent findings involved neurodevelopmental and psychiatric outcomes, with winter births linked to a modest increase in schizophrenia risk (odds ratio (OR) = 1.05) and spring births to multiple sclerosis. Most autoimmune, oncological, and perinatal associations were graded as weak (class III-IV) due to small effect sizes or heterogeneity.Conclusions  The strongest evidence for associations between month/season of birth and long-term health outcomes was restricted to specific neuropsychiatric outcomes, with most other associations graded as weak. Grading the credibility of these associations helps distinguish robust signals from exploratory findings, and provides a clear framework for future mechanistic and epidemiological investigations.Registration  PROSPERO: CRD420251110595.
SN  - 2047-2978
SN  - 2047-2986
ER  -