Table 1 Parental baseline characteristics of the total study population (n = 10,121), Urban China, 2010–2012
From: Paternal factors and adverse birth outcomes in Lanzhou, China
Characteristics | Mother (n = 10,121) | Father (n = 10,121) |
|---|---|---|
Age (years) (mean ± SD) | 28.6 ± 4.4 | 30.7 ± 4.9 |
  < 25 years | 1624 (16.1%) | 804 (7.9%) |
 25 to < 30 years | 4830 (47.7%) | 3541 (35.0%) |
 30 to < 35 years | 2701 (26.7%) | 3821 (37.8%) |
  ≥ 35 years | 966 (9.5%) | 1955 (19.3%) |
Ethnic group | ||
 Han | 9415 (93.0%) | 9291 (91.8%) |
 Others | 706 (7.0%) | 830 (8.2%) |
BMI (kg/m2) (mean ± SD) | 20.68 ± 2.73 | 23.83 ± 3.08 |
  < 18.5 | 2013 (19.9%) | 317 (3.1%) |
 18.5–23.9 | 6682 (66.0%) | 5084 (50.2%) |
  ≥ 24 | 1079 (10.7%) | 4720 (46.6%) |
 Missing | 347 (3.4%) | 0 |
Education status | ||
 Less than high school graduation | 2225 (22.0%) | 2004 (19.8%) |
 high school and community college | 3950 (39.0%) | 3990 (39.4%) |
 higher than college | 3761 (37.2%) | 4127 (40.8%) |
 Missing | 185 (1.8%) | 0 |
Smoking a | ||
 No smoking | 8136 (80.4%) | 5232 (51.7%) |
 Smoking | 1985 (19.6%) | 4889 (48.3%) |
Alcohol use | ||
 No | 10,101 (99.8%) | 7827 (77.3%) |
 Yes | 20 (0.2%) | 2294 (22.6%) |
Employment status | ||
 No | 4897 (48.4%) | 1086 (10.7%) |
 Yes | 5224 (51.6%) | 9035 (89.3%) |
Sex of the child | ||
 boy | 5343 (52.8%) |  |
 girl | 4778 (47.2%) |  |
Parity | ||
 Nulliparous | 7307 (72.2%) |  |
 Parous | 2814 (27.8%) |  |
Cesarean delivery | ||
 No | 6179 (61.1%) |  |
 Yes | 3850 (38.0%) |  |
 Missing | 92 (0.9%) |  |
Hypertensive disorders during pregnancy | ||
 No | 9600 (94.9%) |  |
 Yes | 521 (5.2%) |  |
Diabetes | ||
 Yes | 103 (1.0%) |  |
 No | 10,018 (99.0%) |  |
Family’s average monthly income (yuan) | ||
  ≤ 3000 | 5113 (50.5%) |  |
  > 3000 | 4038 (39.9%) |  |
 missing | 970 (9.6%) |  |