Table 1. Associations of potential predictors for live birth following IVF.
| Characteristic | Categories | Univariable Odds Ratio of Live Birth (95% CI) | Multivariablea Odds Ratio of Live Birth (95% CI) | p-Valueb |
| Maternal age (years) | 18–34 | 1 | 1 | <0.001 |
| 35–37 | 0.77 (0.75–0.79) | 0.78 (0.76–0.81) | ||
| 38–39 | 0.53 (0.51–0.55) | 0.53 (0.51–0.56) | ||
| 40–42 | 0.29 (0.28–0.30) | 0.29 (0.28–0.31) | ||
| 43–44 | 0.10 (0.09–0.12) | 0.10 (0.09–0.12) | ||
| 45–50 | 0.15 (0.12–0.19) | 0.12 (0.09–0.15) | ||
| Duration of infertility (years) | <1 | 1.48 (1.34–1.65) | 1.51 (1.35–1.68) | <0.001 |
| 1–3 | 1.10 (1.07–1.13) | 1.11 (1.08–1.15) | ||
| 4–6 | 1 | 1 | ||
| 7–9 | 0.91 (0.87–0.94) | 0.94 (0.91–0.98) | ||
| 9–12 | 0.81 (0.76–0.85) | 0.87 (0.82–0.92) | ||
| >12 | 0.71 (0.67–0.75) | 0.89 (0.84–0.95) | ||
| Cause of infertility | Unknown | 1 | 1 | <0.001 |
| Tubal only | 0.94 (0.90–0.97) | 0.87 (0.83–0.90) | ||
| Anovulatory only | 0.93 (0.88–0.98) | 0.95 (0.90–1.00) | ||
| Endometriosis only | 1.05 (0.98–1.13) | 0.96 (0.89–1.03) | ||
| Cervical only | 0.41 (0.20–0.85) | 0.39 (0.19–0.82) | ||
| Male only | 1.16 (1.13–1.20) | 0.91 (0.87–0.95) | ||
| Combination known causes | 1.01 (0.96–1.06) | 0.88 (0.83–0.92) | ||
| Number of previous unsuccessful IVF | 0 | 1 | 1 | <0.001 |
| 1 | 0.74 (0.70–0.79) | 0.72 (0.65–0.81) | ||
| 2 | 0.69 (0.64–0.76) | 0.70 (0.62–0.80) | ||
| 3 | 0.74 (0.66–0.84) | 0.77 (0.66–0.91) | ||
| 4 | 0.51 (0.42–0.62) | 0.55 (0.45–0.69) | ||
| ≥5 | 0.57 (0.48–0.69) | 0.68 (0.55–0.83) | ||
| Mutually exclusive categories of previous IVF and obstetric history | No previous IVF, 0 pregnancy | 1 | 1 | <0.001 |
| No previous IVF, at least 1 pregnancy, 0 live births | 0.88 (0.86–0.91) | 1.03 (0.99–1.06) | ||
| No previous IVF, at least 1 pregnancy, at least 1 live birth | 0.92 (0.88–0.96) | 1.19 (1.14–1.24) | ||
| Previous IVF, 0 pregnancy | 0.72 (0.68–0.76) | 1.14 (1.01–1.28) | ||
| Previous IVF, at least 1 pregnancy, 0 live birth | 0.68 (0.64–0.73) | 1.02 (0.93–1.11) | ||
| Previous IVF, at least 1 pregnancy, at least 1 live birth | 1.10 (1.03–1.17) | 1.58 (1.46–1.71) | ||
| Hormonal preparation | Antioestrogen | 1 | 1 | <0.001 |
| Gonadatrophin | 1.43 (1.24–1.63) | 1.33 (1.15–1.53) | ||
| Hormone replacement | 1.61 (1.38–1.89) | 1.55 (1.31–1.82) | ||
| Cycle number | 1 | 1 | 1 | <0.001 |
| 2 | 0.80 (0.78–0.83) | 0.85 (0.82–0.87) | ||
| ≥3 | 0.76 (0.74–0.79) | 0.88 (0.85–0.91) | ||
| Source of egg | Donor | 1 | 1 | <0.001 |
| Patient | 0.87 (0.74–1.02) | 0.38 (0.32–0.45) | ||
| Treatment type | IVF | 1 | 1 | <0.001 |
| ICSI plus IVF | 1.28 (1.25–1.31) | 1.27 (1.23–1.31) |
N = 144,018 analysis cohort with complete data on all variables included in any model.
a
Multivariable adjusted = mutual adjustment for all variables listed in column one.
b
p-Value for multivariable association; all p-values are likelihood ratio tests of null hypothesis that the odds are the same for each category (i.e., they do not assume linearity).