Table 1.
Demographic characteristics of mothers of singleton births and their children in the Ulm Birth Cohort Study (UBCS) (baseline recruitment 2000–2001) and SPATZ (baseline recruitment 2012–2013) cohorts.
| Characteristic | UBCS (n = 1042) |
SPATZ (n = 934) |
|||
|---|---|---|---|---|---|
| n | column% | n | column% | p-value * | |
| Child’s sex | 0.320 | ||||
| Boys | 528 | 50.7% | 494 | 52.9% | |
| Girls | 514 | 49.3% | 440 | 47.1% | |
| Delivery mode | <0.001 | ||||
| Vaginal (spontaneous or assisted) | 875 | 84.0% | 697 | 74.7% | |
| Cesarean (elective or emergency) | 167 | 16.0% | 236 | 25.3% | |
| Gestation age (weeks) † | 1036 | 40.0 (39.0; 40.0) | 933 | 39.0 (38.0; 40.0) | <0.001 |
| Maternal birth country | <0.001 | ||||
| Germany | 828 | 79.5% | 788 | 85.3% | |
| Other | 214 | 20.5% | 136 | 14.7% | |
| Parity (n births of fetus >= 24 weeks) | 0.170 | ||||
| 0 births | 519 | 50.1% | 497 | 53.3% | |
| >= 1 birth | 516 | 49.9% | 436 | 46.7% | |
| Maternal education | <0.001 | ||||
| >= 12 years education | 380 | 37.5% | 545 | 59.6% | |
| < 12 years education | 634 | 62.5% | 370 | 40.4% | |
| Maternal age category [years] | <0.001 | ||||
| <= 25 | 166 | 15.9% | 61 | 6.5% | |
| 26–35 | 689 | 66.2% | 643 | 68.8% | |
| >= 36 | 186 | 17.9% | 230 | 24.6% | |
| Maternal pre-pregnancy BMI [kg/m2] | <0.010 | ||||
| Underweight (BMI < 18.5) | 33 | 3.2% | 21 | 2.3% | |
| Normal (18.5 <= BMI < 25.0) | 696 | 67.4% | 553 | 61.2% | |
| Overweight (25.0 <= BMI < 30.0) | 218 | 21.1% | 209 | 23.1% | |
| Obese (BMI > 30.0) | 86 | 8.3% | 120 | 13.3% | |
| History of smoking | 0.020 | ||||
| No | 704 | 67.6% | 670 | 72.6% | |
| Yes | 337 | 32.4% | 253 | 27.4% | |
| Estimated frequency of feedings per day (6 weeks) | 0.020 | ||||
| <=5 | 179 | (21.0%) | 136 | (16.7%) | |
| >5 | 673 | (79.0%) | 678 | (83.3%) | |
* p-Values are chi-square for association with categorical variables or Kruskal–Wallis for association with continuous variables. Bold indicates significant association (p < 0.05). † Results for gestational age presented as median (25th percentile; 75th percentile). Sums may not add up to total because of missing values for some variables.