Table 1 Demographic characteristics of women in the four groups
| Variable | Group 1 | Group 2 | Group 3 | Group 4 | p-value |
|---|---|---|---|---|---|
| Number of patients, n (%) | 17,504 (91.0) | 835(4.3) | 446(2.3) | 454(2.4) | |
| Maternal age, y | 30.36 ± 4.15a | 32.97 ± 4.80 | 33.17 ± 4.79 | 33.83 ± 5.27 | < 0.001 |
| Body mass index, kg/m2 | 21.87 ± 2.97 | 22.35 ± 3.20* | 21.75 ± 2.84* | 21.85 ± 3.14 | < 0.001 |
| Baseline FSH, mIU/mL | 7.33 ± 1.87 | 9.10 ± 3.51 | 8.53 ± 2.76 | 10.52 ± 4.78 | < 0.001 |
| Antral follicle count (AFC) | 15.05 ± 6.56 | 7.64 ± 2.77* | 3.31 ± 0.95* | 3.18 ± 0.93 | < 0.001 |
| AMH level, ng/ml | 6.04 ± 4.15 | 0.86 ± 0.24* | 2.46 ± 1.41* | 0.69 ± 0.30 | < 0.001 |
| Duration of infertility, years | 3.38 ± 2.46 | 3.41 ± 2.93 | 3.67 ± 2.95 | 3.45 ± 3.15 | 0.012 |
| Infertility diagnosis | < 0.001 | ||||
| Primary infertility, % |
67.2a
(11,767/17504) | 59.6 (498/835) | 57.8 (258/446) | 58.1 (264/454) | |
| Secondary infertility, % | 32.8a (5737/17504) | 40.4 (337/835) | 42.2 (188/446) |
41.9 (190/454) | |
| Infertility etiology, % | < 0.001 | ||||
| Male factor | 23.9 (4176/17504) | 15.6 (130/835) |
12.8 (57/446) |
14.1 (64/454) | |
| Tubal factor | 46.6 (8158/17504) | 36.8 (307/835) | 32.1 (143/446) |
29.7 (135/454) | |
| Ovulatory | 9.6 (1675/17504) |
0.2 (2/835) |
0.9 (4/446) |
0.4 (2/454) | |
| Diminished ovarian reserve | 4.8 (433/17504) | 41.3(345/835) | 47.5(212/446) |
52.9 (240/454) | |
| Unexplained/Other | 15.2 (2662/17504) |
6.1 (51/835) |
6.7 (30/446) |
2.9 (13/454) | |
| Ovarian stimulation protocols | < 0.001 | ||||
| GnRH Antagonist, % |
20.4a
(3576/17504) |
75.8* (633/835) |
92.8* (414/446) |
97.1 (441/454) | |
| Long GnRH-a, % |
29.5a
(5170/17504) | 13.9*(116/835) | 2.7*(12/446) |
0.2 (1/454) | |
| GnRH-a ultra-long, % | 50.1a(8766/17504) | 10.3*(86/835) | 4.5*(20/446) | 2.6(12/454) | |
| Gn duration, days | 10.49 ± 1.94 | 9.73 ± 1.67 | 9.55 ± 1.64 | 9.26 ± 2.01 | < 0.001 |
| Gonadotropin dose, IU | 2311 ± 835a | 2921 ± 781 | 2799 ± 713 | 2813 ± 902 | < 0.001 |
| E2 on hCG, pg/mL | 3137 ± 1900a | 1618 ± 930* | 1980 ± 1105* | 1288 ± 729 | < 0.001 |
| P on hCG day, ng/mL | 0.92 ± 0.54a | 0.74 ± 0.39* | 0.83 ± 0.44* | 0.72 ± 0.49 | < 0.001 |
| No. of oocytes retrieved | 13.65 ± 6.54a | 6.23 ± 3.63 | 6.94 ± 3.67 | 4.34 ± 2.59 | < 0.001 |
| No. of MII oocytes | 11.87 ± 5.92a | 5.48 ± 3.27 | 6.20 ± 3.43 | 3.85 ± 2.43 | < 0.001 |
| Poor ovarian response, % | 2.6a (455/17504) | 24.0* (200/835) |
18.6* (83/446) |
43.0 (195/454) | < 0.001 |
| Suboptimal ovarian response, % | 25.9a (4525/17504) | 60.5 (505/835) |
59.6 (266/446) |
52.9 (240/454) | < 0.001 |
| Oocyte maturation rate | 0.87 ± 0.14a | 0.89 ± 0.17 | 0.90 ± 0.15 | 0.88 ± 0.22 | < 0.001 |
| The number of 2PN | 8.18 ± 4.71 | 3.75 ± 2.70 | 4.27 ± 2.83 | 2.74 ± 2.14 | < 0.001 |
| Normal fertilization rate | 0.64 ± 0.21 | 0.63 ± 0.28 | 0.65 ± 0.26 | 0.63 ± 0.32 | 0.290 |
| Good-quality embryo rate on day 3 | 0.50 ± 0.27 | 0.49 ± 0.33 | 0.51 ± 0.35 | 0.49 ± 0.36 | 0.972 |
| blastocyst formation rate | 0.63 ± 0.29 | 0.56 ± 0.37 | 0.61 ± 0.35 | 0.46 ± 0.40 | < 0.001 |
| No. of available embryos | 8.14 ± 4.78 | 3.75 ± 2.66 | 4.26 ± 2.76 | 2.78 ± 2.16 | < 0.001 |
| Available embryo rate | 0.64 ± 0.22 | 0.63 ± 0.28 | 0.66 ± 0.28 | 0.64 ± 0.32 | 0.027 |
| No. of embryos transferred | 1.01 ± 0.78 | 1.06 ± 0.76 | 0.94 ± 0.76 | 0.88 ± 0.80 | < 0.001 |
| Endometrial thickness, mm | 11.90 ± 2.64 | 11.02 ± 2.55 | 10.88 ± 2.49 | 10.84 ± 2.50 | < 0.001 |
| Cumulative live birth rate, % | 57.8(10,120/17504) | 37.5(313/835) | 36.3(162/446) | 28.2(128/454) | < 0.001 |
| Live birth rate, %b | 33.8a (5924/17483) | 28.9 (241/834) |
23.5 (105/445) |
20.0 c
(91/454) | < 0.001 |
| Live birth rate, %c |
48.2 (5924/12286) | 39.2 (241/615) | 34.5 (105/304) |
32.6 (91/279) | < 0.001 |
| Clinical pregnancy rate, %b | 39.1a (6845/17504) | 35.0 (292/835) |
28.3 (126/446) |
23.3c
(106/454) | < 0.001 |
| Clinical pregnancy rate, %c | 55.6a (6845/12307) | 47.4 (292/616) | 41.3 (126/305) |
38.0 (106/279) | < 0.001 |