Induced abortion linked to later asthma in Chinese women
Among 6,755 women who had been pregnant, one induced abortion was associated with later asthma diagnoses; the hazard ratio, comparing diagnosis rates over time, was 1.49.
8,645 participants, dose-response
Limit: Passive smoking, occupational exposures, and ambient pollution could confound the link; these were unmeasured
A prospective observational cohort study analyzed data from 8,645 Chinese women aged 45 or older collected from 2011 to 2020. Researchers collected reproductive histories in 2014 and identified new asthma diagnoses from women’s reports of physician diagnoses.
Among women who had been pregnant, one induced abortion was associated with later asthma diagnoses. For two or more abortions, the estimate also pointed toward a higher rate, but the range of likely values included no difference. Miscarriage and stillbirth showed no association with asthma. The induced-abortion association persisted across several additional analyses. Separately, each additional live birth was associated with 2.26 liters per minute lower baseline peak expiratory flow, a measure of how fast someone can breathe out.
Why it matters
The results support studying reproductive history alongside lung function when investigating respiratory health in middle-aged and older women.
Caveats
This observational study cannot establish cause and effect, and asthma diagnoses relied on participants’ reports. The preprint has not been peer-reviewed, and its findings concern Chinese women aged 45 or older.
From the paper
- Participants
Among 6,755 ever-pregnant women, one induced abortion was associated with incident asthma (HR 1.49, 95% CI 1.04–2.14), with a similar estimate for two or more abortions (HR 1.66, 95% CI 0.94–2.96).
- Result
Among 6,755 ever-pregnant women, one induced abortion was associated with incident asthma (HR 1.49, 95% CI 1.04–2.14), with a similar estimate for two or more abortions (HR 1.66, 95% CI 0.94–2.96).
- Limitation
Outcomes relied on self-reported physician diagnosis; PEF mitigates but does not eliminate the resulting misclassification, and PEF itself is effort-dependent and less specific than spirometry.
Quoted word for word from the full text on researchsquare.com.
The paper
Jinhua People’s Hospital
Research Square, Oct 19, 2026, Open access, Preprint, not peer-reviewed
