Skip to main content

Table 2 Sex ratio among singleton live births stratified by different demographic characteristics and the embryo culture condition

From: Does the sex ratio of singleton births after frozen single blastocyst transfer differ in relation to blastocyst development?

Characteristic

Singletons (n)

Male (n)

Sex ratio(%)

P-value

Blastocyst quality

   

<0.001

 High

638

383

60.0

 

 Poor

572

284

49.7

 

Maternal age

   

0.261

 <35

971

543

55.9

 

  ≥ 35

239

124

51.9

 

Maternal BMI

   

0.173

 <18.5

47

32

68.1

 

 18.5 ~ 24.9

772

425

55.1

 

  ≥ 25

391

210

53.7

 

Type of infertility

   

0.887

 Primary

541

297

54.9

 

 Secondary

669

370

55.3

 

Cause of infertility

   

0.537

 Female factor

661

363

54.9

 

 Male factor

307

178

58

 

 Combined factor

193

102

52.8

 

 Unexplained

49

24

49

 

Type of fertilization

   

0.191

 IVF

855

461

53.9

 

 ICSI

355

206

58.0

 

Day of frozen embryo

   

0.774

 D5

783

434

55.4

 

 D6

427

233

54.6

 
  1. Note: The sex ratio at birth is calculated as the proportion of males among all livebirths. P < 0.05 was considered statistically significant. CI = confidence interval; BMI = body mass index; D = day; IVF = in vitro fertilization; ICSI = intracytoplasmic sperm injection