| アブストラクト | BACKGROUND: Observational studies of the association between antibiotics and preterm delivery report conflicting findings, with some potentially affected by immortal time bias. We assessed the effects of third-trimester antibiotic use on preterm delivery and low birthweight, using a study design that accounts for immortal time bias. METHODS: We used the UK's Clinical Practice Research Datalink to identify pregnant females aged 12-50, over the period 2002 to 2016, reaching 27 weeks of gestation without antibiotic use until that point. We applied the prevalent new-user design, matching each third-trimester antibiotic initiator with a reference nonuser at the same gestational day, using time-conditional propensity scores. The 2 matched groups were compared on the incidence of preterm delivery and low birthweight. The full cohort was also analyzed with antibiotic use considered as time-fixed and time-varying exposures. RESULTS: The cohort included 207,027 pregnancies, with 16,865 initiating antibiotics matched to 16,865 nonusers. The hazard ratio (HR) of preterm delivery with third-trimester antibiotic use was 1.14 [95% confidence interval (CI): 1.04, 1.24], compared with nonuse. With time-fixed exposure, subject to immortal time bias, the HR was 0.78 (95% CI: 0.73, 0.83), while with time-varying exposure, the HR was 1.23 (95% CI: 1.16, 1.32). The HR of low birthweight with antibiotic initiation was 1.07 (95% CI: 0.93, 1.25) compared with 0.91 (95% CI: 0.83, 1.00) under the time-fixed approach. CONCLUSIONS: Using the prevalent new-user design, which emulates a randomized trial, antibiotic use late in pregnancy was associated with a modestly increased incidence of preterm delivery. Previous inconclusive studies may have resulted from observational methods that introduced, or insufficiently addressed, immortal time bias. |
|---|
| ジャーナル名 | Epidemiology (Cambridge, Mass.) |
|---|
| Pubmed追加日 | 2025/12/30 |
|---|
| 投稿者 | Galmiche, Simon; Comin, Eros; Dell'Aniello, Sophie; Balayla, Jacques; Suissa, Samy |
|---|
| 組織名 | From the Center for Clinical Epidemiology, Lady Davis Institute (LDI), Jewish;General Hospital, Montreal, Canada.;Department of Epidemiology, Biostatistics and Occupational Health, McGill;University, Montreal, Canada.;University of Milano-Bicocca, Milan, Italy.;Department of Obstetrics and Gynecology, McGill University, Montreal, Canada. |
|---|
| Pubmed リンク | https://www.ncbi.nlm.nih.gov/pubmed/41468587/ |
|---|
