Table 2 Parameters of the oocyte thawing cycles
From: Usage and cost-effectiveness of elective oocyte freezing: a retrospective observational study
|  | Total | Age ≤ 35 years | Age 36–39 years | Age ≥ 40 years | P value |
|---|---|---|---|---|---|
Thawing cases | 54 | 11 | 26 | 17 | Â |
Embryo transfer cases/cycles, n/N | 41/52 | 11/16 | 21/26 | 9/10 | Â |
Low ovarian reserve at freezing cycles | 11/54 (20.4) | 0/11 (0.0) | 3/26 (11.5) | 8/17 (47.1) | 0.009 |
Usage rate | 54/645 (8.4) | 11/189 (5.8) | 26/263 (9.9) | 17/193 (8.8) | 0.650 |
Storage duration, y | 3.0 (1.4–4.7) | 3.4 (2.6–4.3) | 3.1 (2.2–5.2) | 2.8 (1.2–4.3) | 0.817 |
Frozen oocytes/case | 10 (5–15) | 14 (10–18) | 10 (7–15) | 4 (2–10) | 0.010 |
Thawed oocytes/case | 9 (5–13) | 13 (8–16) | 9 (7–13) | 4 (2–9) | 0.017 |
Survived oocytes/case | 7 (3–10) | 10 (3–12) | 8 (4–11) | 3 (2–7) | 0.054 |
Survival rate of all oocytes | 382/518 (73.7) | 100/147 (68.0) | 205/262 (78.2) | 77/109 (70.6) | 0.159 |
Frozen MII oocytes/case | 7 (5–13) | 11 (6–17) | 8 (6–13) | 2 (2–10) | 0.022 |
Thawed MII oocytes/case | 7 (5–10) | 8 (5–14) | 8 (5–10) | 2 (2–7) | 0.033 |
Survived MII oocytes/case | 5 (2–9) | 7 (3–11) | 5.5 (3–8) | 2 (1–5) | 0.077 |
Survival rate of MII oocytes | 311/405 (76.8) | 80/110 (72.7) | 164/204 (80.4) | 67/91 (73.6) | 0.528 |
Fertilization rate | 220/332 (66.3) | 61/85 (71.8) | 110/177 (62.1) | 49/70 (70.0) | 0.545 |
Cancel rate | 13/54 (24.1) | 0/11 (0.0) | 5/26 (19.2) | 8/17 (47.1) | 0.038 |
Implantation rate | 29/122 (23.8) | 9/34 (26.5) | 16/66 (24.2) | 4/22 (18.2) | 0.988 |
Clinical pregnancy rate/transfer | 21/52 (40.4) | 8/16 (50.0) | 9/26 (34.6) | 4/10 (40.0) | 0.943 |
Ongoing pregnancy rate/transfer | 18/52 (34.6) | 7/16 (43.8) | 8/26 (30.8) | 3/10 (30.0) | 0.958 |
Total deliveries | 18 | 7 a | 8 | 3 | Â |
Total live births | 21 | 7 | 11 | 3 | Â |
At least one live birth/thawed case | 17/54 (31.5) | 6/11 (54.5) | 8/26 (30.8) | 3/17 (17.6) | 0.320 |
Cumulative live birth/thawed case | 21/54 (38.9) | 7/11 (63.6) | 11/26 (42.3) | 3/17 (17.6) | 0.045 |
Live births/thawed MII oocytes | 21/405 (5.2) | 7/110 (6.4) | 11/204 (5.4) | 3/91 (3.3) | 0.941 |