Table 1 Association of the cytoplasmic halo with cycle characteristics and clinical outcomes

Patients, n

866

36

Female age (y)

36.8 ± 0.1

38.2 ± 0.6

0.0517

Male age (y)

39.3 ± 0.2^a

43.1 ± 1.2^b

0.0001

Previous embryo transfer cycles, n

0.51 ± 0.01

0.50 ± 0.01

0.8992

Cause of infertility

0.9447

 Ovulation, n (%)

30 (3.5)

1 (2.8)

 Tubal factor, n (%)

16 (1.9)

1 (2.8)

 Endometrial factor, n (%)

70 (8.1)

4 (11.1)

 Male factor, n (%)

112 (12.9)

3 (8.3)

 Combined, n (%)

20 (2.3)

1 (2.8)

 Unexplained, n (%)

618 (71.4)

26 (72.2)

Ovarian stimulation

0.8694

 Natural cycle, n (%)

120 (13.9)

4 (11.1)

 Clomiphene citrate cycle, n (%)

685 (79.1)

29 (80.6)

 Letrozole cycle, n (%)

61 (7.0)

3 (8.3)

Oestradiol level on day of the trigger (pg/mL)

777.6 ± 14.1

717.0 ± 63.4

0.3925

Progesterone level on day of the trigger (ng/mL)

0.4 ± 0.0

0.4 ± 0.0

0.2016

Oocytes retrieved, n

1.9 ± 0.0

1.9 ± 0.1

0.8497

Oocyte diameter

113.5 ± 0.2

113.3 ± 0.6

0.7871

Total sperm number (×10⁶)

173.8 ± 6.1

155.7 ± 21.9

0.5539

Motile sperm number (×10⁶)

93.1 ± 3.9

68.9 ± 10.2

0.2067

Motile sperm rate (%)

50.7 ± 0.6

46.6 ± 3.0

0.1883

Abnormal sperm number (×10⁶)

164.6 ± 5.8

147.4 ± 20.7

0.5477

Abnormal sperm rate (%)

94.8 ± 0.1

94.8 ± 0.3

0.8384

Embryos transferred, n

866

36

Blastomeres in embryos transferred

5.8 ± 0.1

5.3 ± 0.3

0.0802

 1, n (%)

133 (15.4)

4 (11.1)

0.4866

 2, n (%)

250 (28.9)

9 (25.0)

0.6152

 3, n (%)

478 (55.2)

21 (58.3)

0.7107

 4, n (%)

5 (0.6)^a

2 (5.6)^b

0.0009

Clinical pregnancy, n (%)

251 (29.0)

6 (16.7)

0.1087

Ongoing pregnancy, n (%)

215 (24.8)

4 (11.1)

0.0600

Live birth, n (%)

183 (21.1)^a

2 (5.6)^b

0.0233

Miscarriage, n (%)

61 (24.3)^a

4 (66.7)^b

0.0183