Table 3.
Association between periconceptionala antibiotic use and spontaneous abortion, by recency of exposure
| No. of SABs | No. of pregnancies | Unadjusted HR (95% CI) | Adjusted HRc (95% CI) | |
|---|---|---|---|---|
| Never use of antibiotics | 1223 | 6848 | 1.00 (Reference) | 1.00 (Reference) |
| Antibiotic use | ||||
| 1–4 weeks before conception | 60 | 276 | 1.25 (0.95, 1.60) | 1.20 (0.92, 1.56) |
| 5–8 weeks before conception | 32 | 148 | 1.24 (0.87, 1.77) | 1.22 (0.85, 1.74) |
| >8 weeks before conception | 17 | 112 | 0.81 (0.49, 1.32) | 0.82 (0.50, 1.35) |
| Up to 5 weeks after conceptionb | 15 | 58 | 1.41 (0.83, 2.38) | 1.46 (0.86–2.47) |
a
Assessed on the questionnaire closest to conception
b
Participant was pregnant, but unaware at study enrollment
c
Adjusted for age, income, education, BMI, multivitamin use, parity, irregular menstrual cycles, doing something to improve chances of conception, intercourse frequency, history of SAB, alcohol intake closest to conception, smoking status closest to conception, pain medication closest to conception, history of pelvic inflammatory disease, history of chlamydia, last method of birth control, geographic region