Table 1 Characteristics of the study population (N = 450 women) undergoing their first recorded fresh IVF or ICSI cycle
Covariate | Pregnancy N = 300 | Non-pregnancy N = 150 | P |
|---|---|---|---|
Age at first cyclea | 31.0 (29.0, 33.0) | 31.0 (29.0, 34.0) | 0.123c |
BMI before transfer, kg/m2, No. (%) | |||
  < 18.5 | 19 (6.3) | 9 (6.0) | 0.954e |
 18.5 ≤ BMI < 24 | 210 (70.0) | 102 (68.0) |  |
 24 ≤ BMI < 28 | 58 (19.3) | 32 (21.3) |  |
 BMI ≥ 28 | 13 (4.3) | 7 (4.7) |  |
Annual Household Income, 10,000 CNY, No. (%) | |||
  < 5 | 12 (4.0) | 7 (4.7) | 0.423e |
 5 ~ 10 | 77 (25.7) | 48 (32.0) |  |
 10 ~ 20 | 118 (39.3) | 49 (32.7) |  |
  > 20 | 93 (31.0) | 46 (30.7) |  |
Occupation (%) | |||
 Mental worker | 150 (50.0) | 73 (48.7) | 0.831d |
 Physical worker | 135 (45.0) | 71 (47.3) |  |
 No | 15 (5.0) | 6 (4.0) |  |
Education, year, No. (%) | |||
  ≥ 12 | 218 (72.7) | 103 (68.7) | 0.439d |
  < 12 | 82 (27.3) | 47 (31.3) |  |
Prior history of pregnancy loss (%) | |||
 Gravid, with no prior history of loss | 12 (4.0) | 8 (5.3) | 0.508e |
 Gravid, with prior history of loss | 14 (4.7) | 10 (6.7) |  |
 Nulliparous | 274 (91.3) | 132 (88.0) |  |
Sleep quality (%)b | |||
 Good | 228 (77.6) | 124 (85.5) | 0.065d |
 Poor | 66 (22.4) | 21 (14.5) |  |
Infertility factor (%) | |||
 Couple’s factor | 181 (60.3) | 99 (66.0) | 0.399e |
 Female factor | 98 (32.7) | 46 (30.7) |  |
 Male factor | 19 (6.3) | 5 (3.3) |  |
 Unexplained factor | 2 (0.7) | 0 (0.0) |  |
Duration of infertility (m) | 36.0 (24.0, 53.0) | 36.0 (24.0, 60.0) | 0.683c |
Smoking before transfer, No. (%) | |||
 Non-smoker | 297 (99.0) | 147 (98.0) | 0.405e |
 Smoker | 3 (1.0) | 3 (2.0) |  |
Alcohol use before transfer, No. (%) | |||
 Rarely | 292 (97.3) | 148 (98.7) | 0.507e |
 Regular | 8 (2.7) | 2 (1.3) |  |
Exercise, No. (%) | |||
 Rarely | 249 (83.0) | 124 (82.7) | 1.000d |
 Regular | 51 (17.0) | 26 (17.3) |  |