Table 2.
Controlled ovarian hyperstimulation characteristics and laboratory outcomes in women receiving embryos vs women receiving at least 1 blastocyst
| All (n = 1579) | D3 embryo transfer only (n = 1300) | At least 1 blastocyst transfered (n = 279) | P-value | |
|---|---|---|---|---|
| Protocol | ||||
| Long protocol | 1200 (76) | 982 (76) | 218 (78) | 0.36 |
| Ultra-long protocol | 379 (34) | 318 (24) | 61 (22) | |
| E2 level on hCG day (pg/mL)a | 3568 (2581, 4529) | 3576 (2615.25, 4529) | 3557.00 (2408, 4596) | 0.28 |
| Progesterone level on hCG day (ng/mL)a | 0.58 (0.43, 0.78) | 0.58 (0.43, 0.78) | 0.58 (0.44, 0.78) | 0.84 |
| LH level on hCG day (mIU/mL)a | 1.55 (1.20, 1.99) | 1.57 (1.22, 1.99) | 1.52 (1.15, 1.99) | 0.43 |
| EM thickness before ET (mm) | 13.30 (12.00, 14.70) | 13.30 (11.90, 14.70) | 13.40 (12.10, 14.60) | 0.87 |
| Gn dosage (IU) | 2100 (1538, 2850) | 2100 (1541, 2850) | 2100 (1538, 2888) | 0.89 |
| Gn duration (days) | 11 (10, 12) | 11 (10, 12) | 11 (10, 12) | 0.92 |
| The dosage of hCG for triggering (IU)a | 6500 (5000, 6500) | 6500 (5000, 6500) | 6500 (5000, 6500) | 0.92 |
| Oocytes retrievedb | 12 (9, 16) | 12 (9, 15) | 12 (9, 16) | 0.25 |
| Degenerated | 0 (0, 0) | 0 (0, 0) | 0 (0, 0) | 0.69 |
| GV | 0 (0, 0) | 0 (0, 0) | 0 (0, 1) | 0.11 |
| MI | 0 (0, 1) | 0 (0, 1) | 0 (0, 1) | 0.73 |
| MII | 11 (8, 14) | 11 (8, 14) | 10 (7, 13) | 0.08 |
| Fertilization methods | ||||
| IVF | 1082 (69) | 895 (69) | 187 (67) | 0.28 |
| ICSI | 261 (17) | 219 (17) | 42 (15) | |
| IVF + ICSI | 236 (15) | 186 (14) | 50 (18) | |
| 2PN zygote | 7 (5, 9) | 7.00 (5, 9) | 6 (4, 9) | 0.10 |
| Fertilization rate | 67 (53, 80) | 67 (54, 80) | 67 (50, 83) | 0.96 |
| Day 3 transferrable embryo | 6 (3, 8) | 6 (4, 8) | 5 (3, 8) | <0.001 |
| Day 3 embryo quality | ||||
| Good quality | 3 (2, 6) | 4 (2, 6) | 4 (2, 6) | 0.93 |
| Fair | 3 (1, 5) | 1 (0, 3) | 1 (0, 2) | 0.06 |
| Embryos or blastocytes transferred | 1.91 ± 0.28 | 1.98 ± 0.12 | 1.58 ± 0.50 | <0.001 |
| Good-quality embryos transferred | 1.58 ± 0.75 | 1.85 ± 0.47 | 0.32 ± 0.48 | <0.001 |
Data are given as median (interquartile range), mean ± SD, or n (%). Three women got D3 embryo and D5 blastocyst transfer; 276 women got D5 blastocyst only. These cases were analyzed together as the “at least 1 blastocyst transferred” group (n = 279). Good-quality embryo, D3 embryo ≥7C-II, blastocyst ≥4BB; fair-quality embryo, D3 embryo <7C-II, blastocyst <4BB.
Abbreviations: 2PN, pronucleus; D3, day 3; E2, estradiol; EM, endometrium; ET, embryo transfer; Gn, gonadotropin; GV, germinal vesicle; hCG, human chorionic gonadotropin; ICSI, intracytoplasmic sperm injection; IVF, in vitro fertilization; LH, luteinizing hormone; MI, metaphase I; MII, metaphase II.
a The last day of ovarian stimulation, hCG was injected to trigger the final maturation of oocytes.
b Reflects oocytes quality; only MII oocyte can be fertilized.