Asthma affects time to pregnancy and fertility: a register-based twin study

Elisabeth Juul Gade, Simon Francis Thomsen, Svend Lindenberg, Kirsten Ohm Kyvik, Sofie Lieberoth, Vibeke Backer
In: European Respiratory Journal · 2013 · vol. 43(4) , pp. 1077–1085 · doi:10.1183/09031936.00148713 · PMID:24232708 · W2162441947
article OA: bronze CC0 ⤵ 3 in-corpus citations
📄 Open PDF View on OpenAlex View on PubMed View at publisher
⚙ AI-generated summary by claude@2026-06, 2026-06-08 ⓘ

This register-based twin study found that asthma is associated with increased time to pregnancy, with effects worsening with age and disease intensity.

One-sentence paraphrase of the abstract; not a substitute for reading it. No clinical advice. How this works

Abstract

Coexistence of infertility and asthma has been observed clinically. Therefore, we investigated the association between asthma and delayed pregnancy in a nationwide population-based cohort of twins. A cohort of 15 250 twins living in Denmark (aged 12-41 years) participated in a questionnaire study including questions about the presence of asthma and fertility. Differences in time to pregnancy and pregnancy outcome were analysed in subjects with asthma, allergy and in healthy individuals using multiple regression analysis. Asthma was associated with an increased time to pregnancy, the percentage of asthmatics with a time to pregnancy >1 year was 27% versus 21.6% for non-asthmatics (OR (95% CI) 1.31 (1.1-1.6); p=0.009). The association remained significant after adjustment for age, age at menarche, body mass index and socioeconomic status (OR (95% CI) 1.25 (1.0-1.6); p=0.05), and was more pronounced in those >30 years of age (32.2% versus 24.9%, OR (95% CI) 1.44 (1.1-1.9); p=0.04). Untreated asthmatics had a significant increased risk of prolonged time to pregnancy compared to healthy individuals (OR (95% CI) 1.79 (1.20-2.66); p=0.004), while asthmatics receiving any kind of treatment for asthma tended to have a shorter time to pregnancy than untreated asthmatics (OR 1.40; p=0.134). Asthma prolongs time to pregnancy. The negative effect of asthma on fertility increases with age and with disease intensity, indicating that a systemic disease characterised by systemic inflammation also can involve reproductive processes.

My notes (saved in your browser only)

Condition tags

infertility

Citation neighborhood (sparse)

Too few in-corpus citations on either side for a chart; here are the lists.

Cites (2)

Cited by (4)

References (46)

Cited by (4)

Source provenance

openalex
last seen: 2026-06-10T17:14:06.276822+00:00
License: CC0 · commercial use OK