Table 2.
Protocols of controlled ovarian hyperstimulation and data of in vitro fertilization and embryo transfer (intention-to-treat analysis).
| Characteristic | No. (%) of participants | P value | |
|---|---|---|---|
| Intervention (n = 443) | Control (n = 443) | ||
| Types of embryo transfer | |||
| Fresh embryo transfer | 159 (36.0) | 168 (38.0) | .54 |
| Frozen thawed embryo transfer | 284 (64.0) | 275 (62.0) | |
| Hormone replacement of frozen thawed embryo transfer | 173 (60.5) | 175 (63.5) | .47 |
| Natural cycle of frozen thawed embryo transfer | 111 (39.5) | 100 (36.5) | |
| Protocol of controlled ovarian hyperstimulation | |||
| Ultralong GnRH agonist | 42 (9.6) | 52 (11.5) | .73 |
| Long GnRH agonist | 138 (31.4) | 128 (29.0) | |
| Short GnRH agonist | 56 (12.5) | 55 (12.4) | |
| GnRH antagonist | 207 (46.5) | 208 (47.1) | |
| Times of ET | |||
| 0 | 199 (44.9) | 209 (47.2) | .57 |
| 1 | 131 (29.6) | 120 (27.1) | |
| 2 | 62 (14.0) | 71 (16.0) | |
| 3 or more | 51 (11.5) | 43 (9.7) | |
| Number of embryos transferred | |||
| 1 | 93 (21.0) | 87 (19.6) | .58 a |
| 2 | 348 (78.6) | 353 (79.7) | |
| 3 | 2 (0.5) | 3 (0.7) | |
| Stage of embryos transferred | |||
| Blastocyst stage | 360 (81.1) | 344 (77.6) | .20 |
| Cleavage stage | 83 (18.9) | 99 (22.4) | |
GnRH, gonadotropin-releasing hormone; ET, embryo transfer.
a
Mann-Whitney U Test.