Table II.
Cycle-specific IVF success and cycle distribution, stratified by age (in years) at the start of cycle 1.
| Cycle number | Number in cohort | Live birth, N (%) | Eligible to return for next cycle | Number (%) not returning for next cycle |
|---|---|---|---|---|
| 1 | 20 015 | 4744 (23.7) | 15 271 | 2951 (19.3) |
| 2 | 12 320 | 2545 (20.7) | 9775 | 2472 (25.3) |
| 3 | 7303 | 1466 (20.1) | 5837 | 1755 (30.1) |
| 4 | 4082 | 723 (17.7) | 3359 | 1145 (34.1) |
| 5 | 2214 | 375 (16.9) | 1839 | 694 (37.7) |
| 6 | 1145 | 178 (15.5) | – | |
| Total cycles | 47 079 | 10 031 (21.3) | – | |
| Age <30 | ||||
| 1 | 2281 | 710 (31.1) | 1571 | 315 (20.1) |
| 2 | 1256 | 354 (28.2) | 902 | 165 (18.3) |
| 3 | 737 | 222 (30.1) | 515 | 123 (23.9) |
| 4 | 392 | 94 (24.0) | 298 | 90 (30.2) |
| 5 | 208 | 60 (28.8) | 148 | 57 (38.5) |
| 6 | 91 | 20 (22.0) | – | |
| Total cycles | 4965 | 1460 (29.4) | – | |
| Age 30 to <35 | ||||
| 1 | 6570 | 2018 (30.7) | 4552 | 671 (14.7) |
| 2 | 3880 | 1005 (25.9) | 2875 | 562 (19.5) |
| 3 | 2313 | 567 (24.5) | 1746 | 458 (26.2) |
| 4 | 1288 | 281 (21.8) | 1007 | 307 (30.5) |
| 5 | 700 | 151 (21.6) | 549 | 184 (33.5) |
| 6 | 365 | 77 (21.1) | – | |
| Total cycles | 15 116 | 4099 (27.1) | – | |
| Age 35 to <38 | ||||
| 1 | 4411 | 1113 (25.2) | 3298 | 530 (16.1) |
| 2 | 2768 | 637 (23.0) | 2131 | 502 (23.6) |
| 3 | 1629 | 319 (19.6) | 1310 | 367 (28.0) |
| 4 | 943 | 170 (18.0) | 773 | 237 (30.7) |
| 5 | 536 | 83 (15.5) | 453 | 151 (33.3) |
| 6 | 302 | 41 (13.6) | – | |
| Total cycles | 10 589 | 2363 (22.3) | – | |
| Age 38 to <41 | ||||
| 1 | 3990 | 713 (17.9) | 3277 | 661 (20.2) |
| 2 | 2616 | 406 (15.5) | 2210 | 623 (28.2) |
| 3 | 1587 | 273 (17.2) | 1314 | 418 (31.8) |
| 4 | 896 | 127 (14.2) | 769 | 268 (34.9) |
| 5 | 501 | 56 (11.2) | 445 | 174 (39.1) |
| 6 | 271 | 29 (10.7) | – | |
| Total cycles | 9861 | 1604 (16.3) | – | |
| Age 41–42 | ||||
| 1 | 1862 | 160 (8.6) | 1702 | 455 (26.7) |
| 2 | 1247 | 121 (9.7) | 1126 | 385 (34.2) |
| 3 | 741 | 71 (9.6) | 670 | 261 (39.0) |
| 4 | 409 | 43 (10.5) | 366 | 164 (44.8) |
| 5 | 202 | 21 (10.4) | 181 | 91 (50.3) |
| 6 | 90 | 9 (10.0) | – | |
| Total cycles | 4551 | 425 (9.3) | – | |
| Age >42 | ||||
| 1 | 901 | 30 (3.3) | 871 | 318 (36.5) |
| 2 | 553 | 22 (4.0) | 531 | 235 (44.3) |
| 3 | 296 | 14 (4.7) | 282 | 128 (45.4) |
| 4 | 154 | 8 (5.2) | 146 | 79 (55.1) |
| 5 | 67 | 4 (6.0) | 63 | 37 (58.7) |
| 6 | 26 | 2 (7.7) | – | |
| Total cycles | 1997 | 80 (4.0) | – |