Table 4.
Cox Regression Analysis of First-Trimester Nonsteroidal Anti-inflammatory Drug Exposure Analyses for Spontaneous Abortion Outcome
Ultrasound findings grouping SABs into developmental stage prior to pregnancy loss are presented. Ultrasounds were conducted at a gestational age in which normal pregnancies would be expected to have a fetal pole and normal heart rate.
| First-Trimester NSAID Exposure | Unadjusted HR | 95% CI | Adjusted (aHR) | 95% CI |
|---|---|---|---|---|
| None | 1.00 | 1.00 | ||
| Any NSAID use | 1.01 | 0.82, 1.24 | 1.00 | 0.81, 1.23 |
| Any NSAID use (losses before 10 weeks) | 0.95 | 0.72, 1.25 | 0.95 | 0.72, 1.25 |
| Any NSAID use (losses 10 weeks or after) | 1.09 | 0.80, 1.48 | 1.09 | 0.80, 1.48 |
| Salicylates NSAID users (aspirin) | 1.33 | 0.97, 1.81 | 1.31 | 0.96, 1.79 |
| Excluding salicylates NSAID users (non-aspirin) | 0.91 | 0.72, 1.15 | 0.91 | 0.72, 1.14 |
| Total days of NSAID use† | 1.01 | 0.99, 1.04 | 1.01 | 0.99, 1.04 |
| 0 | 1.00 | 1.00 | ||
| 1–2 | 0.93 | 0.72, 1.21 | 0.91 | 0.70, 1.17 |
| 3–5 | 1.05 | 0.75, 1.46 | 1.05 | 0.75, 1.46 |
| 6–7 | 1.31 | 0.63, 2.69 | 1.32 | 0.65, 2.69 |
| More than 7 | 1.05 | 0.62, 1.80 | 1.11 | 0.66, 1.89 |
| Total days of NSAID use† (losses before 10 weeks) | 1.02 | 0.99, 1.05 | 1.02 | 0.99, 1.05 |
| 0 | 1.00 | 1.00 | ||
| 1–2 | 0.87 | 0.61, 1.23 | 0.84 | 0.59, 1.19 |
| 3–5 | 0.97 | 0.61, 1.53 | 0.98 | 0.62, 1.55 |
| 6–7 | 1.65 | 0.73, 3.73 | 1.64 | 0.74, 3.67 |
| More than 7 | 1.11 | 0.55, 2.27 | 1.19 | 0.59, 2.39 |
| Total days of NSAID use† (losses 10 weeks or after) | 0.99 | 0.96, 1.03 | 0.99 | 0.96, 1.03 |
| 0 | 1.00 | 1.00 | ||
| 1–2 | 1.01 | 0.69, 1.49 | 0.99 | 0.67, 1.46 |
| 3–5 | 1.14 | 0.70, 1.86 | 1.15 | 0.71, 1.87 |
| 6–7 | 0.76 | 0.19, 3.05 | 0.76 | 0.20, 3.03 |
| More than 7 | 0.99 | 0.44, 2.24 | 1.05 | 0.47, 2.37 |
HR, hazard ratio; CI, confidence interval; aHR, adjusted HR for maternal age; NSAID, nonsteroidal anti-inflammatory drugs.
†
Continuous refers to using days as a continuous outcome.