Table 2.
Demographic and clinical characteristics of couples entered into the study, stratified by TNORCs
| Independent variables | TNORC | ||||
|---|---|---|---|---|---|
| 1 (n = 691) | 2 (n = 398) | 3 (n = 344) | Pa | Overall (n = 1433) | |
| Women’s age (years) | 34.77 (3.19)b | 35.12 (3.33) | 35.48 (3.17) | 0.003 | 35.04 (3.23) |
| 24–41c | 20–42 | 29–41 | 20–42 | ||
| Women’s body mass index (BMI) | 23.16 (3.94) | 23.35 (3.87) | 23.24 (3.48) | 0.731 | 23.23 (3.81) |
| 15.89–51.78 | 17.51–36.73 | 17.04–35.30 | 15.89–51.78 | ||
| Women’s tobacco smokingd | 3.19 (6.431) | 3.59 (6.41) | 4.38 (7.08) | 0.025 | 3.59 (6.60) |
| 0–25 | 0–20 | 0–25 | 0–25 | ||
| No. of antral follicles | 15.25 (8.68) | 14.94 (8.12) | 13.92 (8.14) | 0.053 | 14.84 (8.41) |
| 1–71 | 3–54 | 3–54 | 1–71 | ||
| Duration of infertility (years) | 2.61 (1.58) | 2.64 (1.57) | 2.81 (1.77) | 0.162 | 2.66 (1.62) |
| 0–14 | 0–10 | 0–13 | 0–14 | ||
| Type of menstrual cycle | 0.382 | ||||
| Regular | 590 (85.4)e | 334 (83.9) | 299 (88.0) | 1223 (85.5) | |
| Irregular | 96 (13.9) | 57 (14.0) | 43 (11.3) | 196 (13.4) | |
| Amenorrhea | 5 (0.7) | 7 (2.1) | 2 (0.7) | 14 (1.1) | |
| Women’s medical conditionf,g | 0.141 | ||||
| Healthy | 535 (77.4) | 291 (73.1) | 250 (72.7) | 1076 (75.1) | |
| Diseased | 156 (22.6) | 107 (26.9) | 94 (27.3) | 357 (24.9) | |
| Men’s medical conditionf,h | 0.903 | ||||
| Healthy | 593 (85.8) | 342 (85.9) | 292 (84.9) | 1227 (85.6) | |
| Diseased | 98 (14.2) | 56 (14.1) | 52 (15.1) | 206 (14.4) | |
| Male infertility etiology | 0.0005 | ||||
| Donor sperm | 18 (2.6) | 7 (1.8) | 5 (1.5) | 30 (2.1) | |
| Oligo-, astheno-, and/or teratozoospermia | 271 (39.2) | 191 (48.0) | 165 (48.0) | 627 (43.8) | |
| Cryptozoospermia or azoospermia | 67 (9.7) | 50 (12.6) | 53 (15.4) | 170 (11.9) | |
| Unknown (normozoospermia) | 335 (48.5) | 150 (37.7) | 121 (35.2) | 606 (42.3) |
aThe adjusted/corrected Benjamini & Hochberg’s significance is P ≤ 0.029, based on 14 statistical tests applied
bValues are crude means and standard deviations in parenthesis
cMinimum and maximum values
dNumber of cigarettes smoked per day for the 3 months before starting the first intended oocyte retrieval cycle
eValues are absolute frequencies and percentages in parenthesis
fMedical conditions were assessed following the International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10 Version: 2016). Only ICD-10 chapters with sample sizes ≥ 10 women/men were included in the study as distinct groups. ICD-10 chapters with sample sizes < 10 women/men were combined in a single “catch-all” group called “other diseases” [14]
gICD-10 chapters: “Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism” (n = 23), “Endocrine, nutritional and metabolic diseases” (n = 187), “Mental and behavioral disorders” (n = 17), “Diseases of the nervous system” (n = 22), “Diseases of the circulatory system” (n = 18), “Diseases of the respiratory system” (n = 23), “Diseases of the digestive system” (n = 20), “Diseases of the musculoskeletal system and connective tissue” (n = 17), and “other diseases” (n = 30)
hICD-10 chapters: “Endocrine, nutritional and metabolic diseases” (n = 33), “Diseases of the circulatory system” (n = 40), “Diseases of the respiratory system” (n = 27), “Diseases of the digestive system” (n = 23), “Diseases of the genitourinary system” (n = 15), and “other diseases” (n = 68)