Table 1.
Baseline and cycle characteristics grouped by the vaccination status.
| Before matching |
After matching |
|||||
|---|---|---|---|---|---|---|
| Vaccinated (n = 387) |
Unvaccinated (n = 823) |
P value | Vaccinated (n = 265) |
Unvaccinated (n = 265) |
P value | |
| Age at OPU (years) | 30.3 ± 4.7 | 31.3 ± 5.4 | 0.002 | 31.0 ± 4.8 | 30.9 ± 4.7 | 0.824 |
| Age at ET (years) | 32.8 ± 4.5 | 32.1 ± 5.4 | 0.010 | 32.6 ± 4.7 | 32.3 ± 4.8 | 0.557 |
| Body mass index (kg/m2) | 22.1 ± 2.5 | 22.0 ± 3.2 | 0.256 | 22.2 ± 2.6 | 22.2 ± 3.3 | 0.474 |
| Infertility duration (years) | 6.3 ± 3.5 | 4.8 ± 3.4 | <0.001 | 5.4 ± 3.2 | 5.0 ± 3.1 | 0.056 |
| Infertility type, n (%) | <0.001 | 0.489 | ||||
| Primary | 72 (18.6) | 295 (35.8) | 66 (24.9) | 73 (27.6) | ||
| Secondary | 315 (81.4) | 528 (64.2) | 199 (75.1) | 192 (72.5) | ||
| Infertility diseases | ||||||
| Tubal factor, n (%) | 266 (68.7) | 588 (71.5) | 0.334 | 179 (67.6) | 198 (74.7) | 0.069 |
| Male factor, n (%) | 98 (25.3) | 199 (24.2) | 0.667 | 52 (19.6) | 68 (25.7) | 0.097 |
| Ovulatory dysfunction, n (%) | 64 (16.5) | 156 (19.0) | 0.309 | 41 (15.5) | 40 (15.1) | 0.904 |
| Diminished ovarian reserve, n (%) | 47 (12.1) | 157 (19.1) | 0.003 | 41 (15.5) | 38 (14.3) | 0.714 |
| Endometriosis, n (%) | 35 (9.0) | 43 (5.2) | 0.012 | 24 (9.1) | 20 (7.6) | 0.529 |
| Uterine factor, n (%) | 47 (12.1) | 84 (10.2) | 0.312 | 35 (13.2) | 28 (10.6) | 0.348 |
| Ovarian stimulation protocol, n (%) | <0.001 | 0.493 | ||||
| GnRH agonist | 316 (81.7) | 548 (66.6) | 201 (75.9) | 211 (79.6) | ||
| GnRH antagonist | 33 (8.5) | 136 (16.5) | 31 (11.7) | 29 (10.9) | ||
| Others | 38 (9.8) | 139 (16.9) | 33 (12.5) | 25 (9.4) | ||
| Fertilization method, n (%) | 0.205 | 0.760 | ||||
| IVF | 299 (77.3) | 608 (73.9) | 203 (76.6) | 200 (75.5) | ||
| ICSI | 88 (22.7) | 215 (26.1) | 62 (23.4) | 65 (24.5) | ||
| Prior ET failure, n (%) | 0.525 | 0.797 | ||||
| 0 | 212 (54.8) | 477 (58.0) | 132 (49.8) | 131 (49.4) | ||
| 1–2 | 167 (43.2) | 327 (39.7) | 128 (48.3) | 131 (49.4) | ||
| ≥3 | 8 (2.1) | 19 (2.3) | 5 (1.9) | 3 (1.1) | ||
| Endometrial preparation, n (%) | 0.011 | 0.649 | ||||
| Artificial cycle with GnRH agonist | 215 (55.6) | 531 (64.5) | 150 (56.6) | 160 (60.4) | ||
| Artificial cycle | 130 (33.6) | 224 (27.2) | 89 (33.6) | 83 (31.3) | ||
| Natural cycle | 42 (10.9) | 68 (8.3) | 26 (9.8) | 22 (8.3) | ||
| Endometrial thickness (mm) | 9.3 ± 1.7 | 9.5 ± 1.8 | 0.477 | 9.3 ± 1.6 | 9.3 ± 1.8 | 0.521 |
| No. of embryos transferred, n (%) | <0.001 | 0.223 | ||||
| 1 | 199 (51.4) | 318 (38.6) | 130 (49.1) | 116 (43.8) | ||
| 2 | 188 (48.6) | 505 (61.4) | 135 (50.9) | 149 (56.2) | ||
| Embryo developmental stage, n (%) | <0.001 | 0.927 | ||||
| Cleavage | 121 (31.3) | 371 (45.1) | 89 (33.6) | 88 (33.2) | ||
| Blastocyst | 266 (68.7) | 452 (54.9) | 176 (66.4) | 177 (66.8) | ||
| Transfer of ≥1 top-quality embryo, n (%) | 206 (53.2) | 522 (63.4) | 0.001 | 145 (54.7) | 148 (55.9) | 0.793 |
Notes: Data are presented as mean ± standard deviation or number (percentage).
Abbreviations: OPU, oocyte pick-up; ET, embryo transfer; IVF, in vitro fertilization; ICSI, intracytoplasmic sperm injection; GnRH, gonadotropin-releasing hormone.