Table 2.
Maternal age, the number of oocytes retrieved and embryos available in both two groups, stratified by time to pregnancy.
| Time to pregnancy, months | P value1 | |||||
|---|---|---|---|---|---|---|
| ≤ 24 | 25–48 | ≥ 49 | P1 | P2 | P3 | |
| EP group | ||||||
| N (%) | 252 (46.1) | 163 (29.8) | 132 (24.1) | – | – | – |
| Maternal age (median and range) | 31 (22–45) | 33 (23–45) | 35 (25–45) | 0.005 | < 0.001 | < 0.001 |
| No. of oocytes retrieved (median and range) | 9 (1–35) | 7 (1–29) | 5 (1–22) | 0.002 | < 0.001 | < 0.001 |
| No. of embryos available (median and range) | 5 (1–19) | 5 (1–21) | 4 (1–15) | 0.091 | < 0.001 | < 0.001 |
| Control group | ||||||
| N (%) | 258 (46.9) | 223 (40.5) | 69 (12.5) | – | – | – |
| Maternal age (median and range) | 32 (20–43) | 31 (23–44) | 31 (23–45) | 0.992 | 0.377 | 0.402 |
| No. of oocytes retrieved (median and range) | 10 (1–29) | 8 (1–39) | 7 (2–27) | 0.085 | 0.585 | 0.463 |
| No. of embryos available (median and range) | 6 (1–18) | 6 (1–29) | 6 (1–17) | 0.206 | 0.991 | 0.470 |
| P value defined as the comparison in maternal age between EP and control group | 0.435 | 0.029 | < 0.001 | |||
| P value defined as the comparison in number of oocytes retrieved between EP and control group | 0.013 | < 0.001 | < 0.001 | |||
| P value defined as the comparison in number of embryos available between EP and control group | 0.202 | < 0.001 | < 0.001 | |||
1We defined the statistical outcomes of ≤ 24 months group versus 25–48 months group as P1; ≤ 24 months group versus ≥ 49 months group as P2; 25–48 months group versus ≥ 61 months group as P3. IVF in vitro fertilization, EP ectopic pregnancy.