Table 1 General characteristics and clinical outcomes of patients with different endometrial preparation protocols

Maternal age at oocyte retrieval, y

31.0 (29.0, 35.0)

31.0 (29.0, 35.0)

32.0 (30.0, 35.0)

0.201³

Body mass index, kg/m²

20.8 (19.4, 22.5)

20.8 (19.5, 22.8)

21.1 (19.6, 22.6)

0.742³

Baseline FSH, mIU/mL

7.8 (6.6, 9.6)

7.8 (6.5, 9.0)

7.9 (6.4, 9.8)

0.665³

Antral follicle count (AFC)

8.0 (5.0, 11.0)

9.0 (6.0, 14.0)

7.0 (4.0, 13.0)

<.001^3*

AMH level, ng/ml

2.4 (1.4, 4.5)

2.8 (1.7, 5.3)

2.1 (1.2, 4.0)

<.001^3*

Duration of infertility, years

2.0 (1.5, 4.0)

3.0 (2.0, 4.0)

3.0 (2.0, 5.0)

0.006^3*

Infertility diagnosis

0.969¹

Primary infertility, n (%)

257 (66.1%)

629 (66.2%)

50 (67.6%)

Secondary infertility, n (%)

132 (33.9%)

321 (33.8%)

24 (32.4%)

 Male factor

64 (16.5%)

167 (17.6%)

19 (25.7%)

0.161¹

 Female factors

  Tubal factor

189 (48.6%)

472 (49.7%)

35 (47.3%)

0.881¹

  Ovulatory

3 (0.8%)

42 (4.4%)

1 (1.4%)

0.001^2*

  Diminished ovarian reserve

115 (29.6%)

218 (22.9%)

19 (25.7%)

0.039^1*

  Uterine malformation

105 (27.0%)

187 (19.7%)

21 (28.4%)

0.006^1*

 Unexplained/Other

0 (0.0%)

6 (0.6%)

1 (1.4%)

0.115²

Ovarian stimulation protocols, n (%)

<.001^1*

 Long GnRH-a

43 (11.1%)

165 (17.4%)

12 (16.2%)

 GnRH-a ultra-long

98 (25.2%)

342 (36.0%)

25 (33.8%)

 GnRH antagonist

146 (37.5%)

198 (20.8%)

16 (21.6%)

 Other protocols

102 (26.2%)

245 (25.8%)

21 (28.4%)

Duration of stimulation, days

10.0 (9.0, 11.0)

10.0 (9.0, 11.0)

10.0 (9.0, 11.0)

0.018^3*

Gonadotropin dose, IU

2625.0 (2100.0, 3150.0)

2475.0 (1912.5, 3000.0)

2625.0 (2137.5, 3150.0)

0.011^3*

No. of oocytes retrieved

9.0 (5.0, 14.0)

10.0 (6.0, 16.0)

8.0 (5.0, 14.0)

0.003^3*

No. of MII oocytes

7.0 (4.0, 12.0)

9.0 (5.0, 14.0)

7.0 (4.0, 12.0)

0.001^3*

Oocyte maturation rate

0.9 (0.8, 1.0)

0.9 (0.8, 1.0)

0.9 (0.8, 1.0)

0.478³

Fertilization, n (%)

0.070¹

 IVF

105 (27.0%)

199 (20.9%)

23 (31.1%)

 ICSI

266 (68.4%)

698 (73.5%)

48 (64.9%)

 Rescue ICSI

18 (4.6%)

53 (5.6%)

3 (4.1%)

The number of 2PN

5.0 (3.0, 9.0)

6.0 (4.0, 10.0)

5.0 (3.0, 10.0)

0.012^3*

Normal fertilization rate

0.7 (0.5, 0.9)

0.7 (0.5, 0.8)

0.7 (0.5, 0.9)

0.187³

Blastocyst formation rate

0.8 (0.5, 1.0)

0.7 (0.5, 0.9)

0.7 (0.5, 1.0)

0.025^3*

Maternal age at FET, y

32.0 (29.0, 35.0)

32.0 (29.0, 35.0)

33.0 (31.0, 35.0)

0.063³

Interval between FET and IVF/ICSI, days

125.0 (85.0, 248.0)

91.0 (60.0, 172.0)

112.0 (63.0, 263.0)

<.001^3*

No. of embryos thawed

0.226²

 1

242 (62.2%)

537 (56.5%)

44 (59.5%)

 2

143 (36.8%)

393 (41.4%)

28 (37.8%)

 > = 3

4 (1.0%)

20 (2.1%)

2 (2.7%)

No. of surviving embryos

0.194²

 1

243 (62.5%)

540 (56.8%)

44 (59.5%)

 2

143 (36.8%)

394 (41.5%)

28 (37.8%)

 3

3 (0.8%)

16 (1.7%)

2 (2.7%)

total no. of surviving embryos/no. of embryos thawed

1.0 (1.0, 1.0)

1.0 (1.0, 1.0)

1.0 (1.0, 1.0)

0.528³

No. of embryos transferred, n (%)

0.324¹

 1

249 (64.0%)

568 (59.8%)

47 (63.5%)

 2

140 (36.0%)

382 (40.2%)

27 (36.5%)

Type of embryo transferred, n (%)

0.029^1*

 Cleavage embryo

142 (36.5%)

296 (31.2%)

32 (43.2%)

 Blastocyst

247 (63.5%)

654 (68.8%)

42 (56.8%)

Endometrial thickness, mm

9.7 (8.8, 11.0)

9.2 (8.4, 10.1)

9.7 (8.8, 10.5)

<.001^3*

Luteal phase support, n (%)

<.001^1*

 Intramuscular injection and oral administration

11 (2.8%)

179 (18.8%)

10 (13.5%)

 Vaginal gel administration and oral administration

179 (46.0%)

387 (40.7%)

26 (35.1%)

 Vaginal suppository administration and oral administration

197 (50.6%)

381 (40.1%)

24 (32.4%)

 Others

2 (0.5%)

3 (0.3%)

14 (18.9%)

Live Birth, n (%)

156 (40.1%)

384 (40.4%)

30 (40.5%)

0.994¹

Clinical Pregnancy, n (%)

200 (51.4%)

475 (50.0%)

34 (45.9%)

0.677¹

Miscarriage, n (%)

44 (11.3%)

91 (9.6%)

4 (5.4%)

0.281²

Multiple pregnancy, n (%)

37 (9.5%)

108 (11.4%)

4 (5.4%)

0.221²

Biochemical Pregnancy, n (%)

29 (7.5%)

61 (6.4%)

2 (2.7%)

0.321²

Ectopic pregnancy, n (%)

2 (0.5%)

7 (0.7%)

0 (0.0%)

>.999²