Table 2.
Outcomes of cycles according to the cause of infertility
| Outcome | Female factor | Unexplained factor | |||||
|---|---|---|---|---|---|---|---|
| IVF | ICSI | p | IVF | ICSI | p | ||
| Cycles | N | 53,374 | 13,995 | 71,650 | 30,573 | ||
| Fertilization rate* | Median (IQR) | 67% (50–83%) | 75% (57–88%) | < 0.001 | 67% (47–83%) | 73% (54–88%) | < 0.001 |
| Freeze all | N (%) | 2942 (5.5%) | 821 (5.9%) | 0.10 | 2894 (4.0%) | 1384 (4.5%) | < 0.001 |
| No available embryos | N (%) | 2741 (5.1%) | 561 (4.0%) | < 0.001 | 5083 (7.1%) | 1587 (5.2%) | < 0.001 |
| N of embryos transferred | Mean (SD) | 1.56 (0.53) | 1.59 (0.55) | < 0.001 | 1.58 (0.55) | 1.59 (0.57) | 0.050 |
| 1 | N (%) | 21,539 (45.2%) | 5570 (44.2%) | < 0.001 | 28,303 (44.5%) | 12,438 (45.1%) | < 0.001 |
| 2 | N (%) | 25,451 (53.4%) | 6696 (53.1%) | 33,597 (52.8%) | 14,007 (50.7%) | ||
| 3 | N (%) | 701 (1.5%) | 347 (2.8%) | 1773** (2.8%) | 1157 (4.2%) | ||
| Embryo transfer stage | |||||||
| Cleavage stage | N (%) | 28,901 (60.6%) | 7162 (56.8%) | < 0.001 | 37,686 (59.2%) | 15,180 (55.0%) | < 0.001 |
| Blastocyst stage | N (%) | 18,121 (38.0%) | 5219 (41.4%) | 25,188 (39.6%) | 11,903 (43.1%) | ||
| Other/unspecified | N (%) | 669 (1.4%) | 232 (1.8%) | 799 (1.3%) | 519 (1.9%) | ||
| Cycles with ≥ 1 embryo stored | N (%) | 22,562 (42.3%) | 5555 (39.7%) | < 0.001 | 27,157 (37.9%) | 11,348 (37.1%) | 0.018 |
| 1–5 embryos | N (%) | 16,927 (31.7%) | 4398 (31.4%) | < 0.001 | 21,668 (30.2%) | 9449 (30.9%) | < 0.001 |
| > 5 embryos | N (%) | 5635 (10.6%) | 1157 (8.3%) | 5489 (7.7%) | 1899 (6.2%) | ||
| Pregnancies with FHB | N; % (95%CI) | 17,893; 33.5% (33.1–33.9%) | 4617; 33.0% (32.2–33.8%) | 0.23 | 22,669; 31.6% (31.3–32.0%) | 9743; 31.9% (31.4–32.4%) | 0.43 |
| Implantation rate (with FHB) | |||||||
| Single embryo transfer | N Implanted/transferred | 8331/21539 | 2057/5570 | 0.017 | 10,392/28303 | 4462/12438 | 0.10 |
| % (95%CI) | 38.7% (38.0–39.3%) | 36.9% (35.7–38.2%) | 36.7% (36.2–37.3%) | 35.9% (35.0–36.7%) | |||
| Double embryo transfer | N Implanted/transferred | 12,363/50902 | 3288/13392 | 0.53 | 15,270/67194 | 6379/28014 | 0.88 |
| % (95%CI) | 24.3% (23.9–24.7%) | 24.6% (23.8–25.3%) | 22.7% (22.4–23.0%) | 22.8% (22.3–23.3%) | |||
| Triple embryo transfer | N Implanted/transferred | 164/2103 | 70/1041 | 0.24 | 435/5320** | 312/3471 | 0.19 |
| % (95%CI) | 7.8% (6.7–8.9%) | 6.7% (5.2–8.2%) | 8.2% (7.4–8.9%) | 9.0% (8.0–9.9%) | |||
| Live birth occurrence | N; % (95%CI) | 15,847; 29.7% (29.3–30.1%) | 4030; 28.8% (28.0–29.5%) | 0.039 | 19,847; 27.7% (27.4–28.0%) | 8479; 27.7% (27.2–28.2%) | 0.91 |
*cycles perfomed in 2017–2018 were excluded since the number of inseminated/fertilized eggs are available as categorical data only; ** includes 1 transfer with 4 embryos
IVF, conventional in vitro insemination; ICSI, intracytoplasmic sperm injection, FHB, fetal heartbeat; IQR, interquartile range; SD, standard deviation; 95% CI, 95% confidence interval