Table 3 General characteristics and perinatal outcomes of patients with singleton live births

Maternal age at oocyte retrieval, y

30.0 (28.0, 33.0)

30.0 (28.0, 33.0)

32.0 (29.0, 33.0)

0.305³

Body mass index, kg/m²

20.7 (19.2, 22.1)

20.8 (19.5, 22.6)

21.6 (19.7, 22.9)

0.340³

Baseline FSH, mIU/mL

7.7 (6.5, 8.9)

7.5 (6.3, 8.8)

7.7 (6.2, 8.5)

0.757³

Antral follicle count (AFC)

8.0 (5.0, 12.0)

11.0 (7.0, 15.5)

9.5 (6.0, 18.0)

<.001^3*

AMH level, ng/ml

2.7 (1.4, 4.9)

3.3 (2.1, 5.6)

3.0 (1.6, 4.8)

0.014^3*

Duration of infertility, years

2.0 (1.5, 3.0)

3.0 (1.5, 4.0)

3.0 (2.0, 3.0)

0.284³

Infertility diagnosis

0.747¹

Primary infertility, n (%)

91 (69.5%)

219 (72.0%)

20 (66.7%)

Secondary infertility, n (%)

40 (30.5%)

85 (28.0%)

10 (33.3%)

 Male factor

21 (16.0%)

50 (16.4%)

5 (16.7%)

>.999²

 Female factors

  Tubal factor

67 (51.1%)

155 (51.0%)

15 (50.0%)

0.994¹

  Ovulatory

1 (0.8%)

12 (3.9%)

1 (3.3%)

0.164²

  Diminished ovarian reserve

29 (22.1%)

43 (14.1%)

3 (10.0%)

0.082²

  Uterine malformation

30 (22.9%)

44 (14.5%)

9 (30.0%)

0.022^1*

 Unexplained/Other

0 (0.0%)

3 (1.0%)

0 (0.0%)

0.638²

Ovarian stimulation protocols, n (%)

0.005^1*

 Long GnRH-a

21 (16.0%)

66 (21.7%)

8 (26.7%)

 GnRH-a ultra-long

34 (26.0%)

124 (40.8%)

13 (43.3%)

 GnRH antagonist

47 (35.9%)

65 (21.4%)

5 (16.7%)

 Other protocols

29 (22.1%)

49 (16.1%)

4 (13.3%)

Duration of stimulation, days

10.0 (9.0, 11.0)

10.0 (9.0, 11.0)

10.0 (10.0, 12.0)

0.020^3*

Gonadotropin dose, IU

2625.0 (2025.0, 3165.0)

2400.0 (1875.0, 3000.0)

2550.0 (2100.0, 3075.0)

0.161³

No. of oocytes retrieved

9.0 (5.0, 14.0)

12.0 (8.0, 17.0)

11.0 (7.0, 16.0)

<.001^3*

No. of MII oocytes

8.0 (4.0, 12.0)

11.0 (7.0, 15.0)

10.0 (6.0, 14.0)

<.001^3*

Oocyte maturation rate

0.9 (0.8, 1.0)

0.9 (0.8, 1.0)

0.9 (0.9, 1.0)

0.745³

Fertilization, n (%)

0.343²

 IVF

35 (26.7%)

62 (20.4%)

5 (16.7%)

 ICSI

88 (67.2%)

225 (74.0%)

25 (83.3%)

 Rescue ICSI

8 (6.1%)

17 (5.6%)

0 (0.0%)

The number of 2PN

6.0 (3.0, 8.0)

7.0 (4.5, 10.5)

8.0 (4.0, 11.0)

0.004^3*

Normal fertilization rate

0.7 (0.6, 0.9)

0.7 (0.6, 0.8)

0.7 (0.6, 0.9)

0.146³

Blastocyst formation rate

0.8 (0.6, 1.0)

0.8 (0.5, 0.9)

0.7 (0.5, 0.8)

0.117³

Maternal age at FET, y

31.0 (28.0, 34.0)

31.0 (29.0, 33.0)

32.0 (30.0, 33.0)

0.327³

Interval between FET and IVF/ICSI, days

131.0 (85.0, 229.0)

90.5 (60.0, 166.0)

80.5 (59.0, 220.0)

<.001^3*

No. of embryos thawed

0.480²

 1

19 (63.3%)

187 (61.5%)

89 (67.9%)

 2

10 (33.3%)

113 (37.2%)

41 (32.1%)

 > = 3

1 (3.3%)

4 (1.3%)

1 (0.8%)

No. of surviving embryos

0.314²

 1

19 (63.3%)

188 (61.8%)

89 (67.9%)

 2

10 (33.3%)

113 (37.2%)

42 (32.1%)

 > = 3

1 (3.3%)

3 (1.0%)

0 (0.0%)

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)

0.895³

No. of embryos transferred, n (%)

0.816¹

 1

89 (67.9%)

198 (65.1%)

19 (63.3%)

 2

42 (32.1%)

106 (34.9%)

11 (36.7%)

Type of embryo transferred, n (%)

0.051¹

 Cleavage embryo

35 (26.7%)

52 (17.1%)

8 (26.7%)

 Blastocyst

96 (73.3%)

252 (82.9%)

22 (73.3%)

Endometrial thickness, mm

10.1 (8.9, 11.3)

9.3 (8.6, 10.3)

9.3 (8.7, 10.4)

<.001^3*

Luteal phase support, n (%)

<.001^1*

 Intramuscular injection and oral administration

1 (0.8%)

60 (19.7%)

5 (16.7%)

 Vaginal gel administration and oral administration

64 (48.9%)

128 (42.1%)

9 (30.0%)

 Vaginal suppository administration and oral administration

66 (50.4%)

115 (37.8%)

9 (30.0%)

 Others

0 (0.0%)

1 (0.3%)

7 (23.3%)

Gestational age, wk

38.9 (38.0, 39.4)

39.0 (38.0, 39.6)

38.6 (37.0, 39.0)

0.082³

Birth weight, kg

3.3 (3.0, 3.6)

3.4 (3.1, 3.7)

3.2 (2.7, 3.6)

0.237³

Delivery mode, n (%)

0.848¹

 Cesarean delivery

114 (87.0%)

260 (85.5%)

25 (83.3%)

 Natural labor

17 (13.0%)

44 (14.5%)

5 (16.7%)

Gender, n (%)

0.160¹

 Male

81 (61.8%)

159 (52.3%)

15 (50.0%)

 Female

50 (38.2%)

145 (47.7%)

15 (50.0%)

Low birth weight < 2500 g

9 (6.9%)

19 (6.3%)

2 (6.7%)

0.952²

Macrosomia > 4000 g

5 (3.8%)

18 (5.9%)

1 (3.3%)

0.726²

Small for gestational age, n (%)

10 (7.6%)

17 (5.6%)

4 (13.3%)

0.194²

Large for gestational age, n (%)

21 (16.0%)

51 (16.8%)

5 (16.7%)

0.979¹

Preterm birth < 37 wk., n (%)

16 (12.2%)

37 (12.2%)

4 (13.3%)

0.945²

Gestational diabetes mellitus, n (%)

4 (3.1%)

18 (5.9%)

3 (10.0%)

0.185²

Hypertensive disorders of pregnancy, n (%)

125 (95.4%)

291 (95.7%)

29 (96.7%)

>.999²

Placenta previa, n (%)

8 (6.1%)

19 (6.3%)

2 (6.7%)

>.999²

Fetal malformation, n (%)

2 (1.5%)

11 (3.6%)

1 (3.3%)

0.510²