Table 1.
Basic characteristics of the participants aged <35 years and ≥35 years.
| Maternal Characteristics/Pregnancy Outcomes | Women <35 Years (n = 433) |
Women ≥35 Years (n = 479) |
|
|---|---|---|---|
| Median (IQ Range)/n(%) | Median (IQ Range)/n(%) | p * | |
| Maternal age (years) | 30 (28–32) | 37 (36–39) | <0.001 |
| Primiparity | 244 (56.4%) | 138 (28.8%) | <0.001 |
| Treatment of infertility | 14 (3.2%) | 26 (5.4%) | 0.106 |
| Pre-pregnancy BMI (kg/m2) | 22.1 (20.3–24.9) | 23.6 (21.1–27.2) | <0.001 |
| BMI categories | <0.001 | ||
| Obesity | 36 (8.3%) | 62 (12.9%) | |
| Overweight | 70 (16.2%) | 103 (21.5%) | |
| Normal BMI | 295 (68.1%) | 299 (62.4%) | |
| Underweight | 32 (7.4%) | 15 (3.1%) | |
| Gestational weight gain (kg) | 14 (10–17) | 13 (10–17) | 0.010 |
| Smoking before pregnancy | 84 (19.4%) | 84 (17.5%) | 0.469 |
| Smoking in I trimester | 29 (6.7%) | 28 (5.8%) | 0.596 |
| Multivitamins in pregnancy | 273 (63%) | 254 (53%) | 0.002 |
| Education <12 years # | 22 (5.7%) | 48 (11.7%) | 0.003 |
| Lower financial status # | 62 (23.8%) | 69 (30%) | 0.125 |
| Fetal sex, son | 220 (50.8%) | 253 (52.8%) | 0.544 |
| Gestational age | 39 (38–40) | 39 (38–40) | <0.001 |
| Birth <37th week | 22 (5.1%) | 43 (9.0%) | 0.022 |
| IUGR | 10 (2.3%) | 11 (2.3%) | 0.991 |
| Birth weight | 3410 (3090–3700) | 3400 (3065–3745) | 0.947 |
| Birth weight in percentiles | 0.460 | ||
| <10th percentile | 30 (6.9%) | 42 (8.8%) | |
| 10–90 percentile | 365 (84.3%) | 376 (78.5%) | |
| >90th percentile | 38 (8.8%) | 61 (12.7%) | |
| Birth weight in grams | 0.696 | ||
| <2500 g | 19 (4.4%) | 41 (8.6%) | |
| 2500–4000 g | 375 (86.6%) | 380 (79.3%) | |
| >4000 g | 39 (9.0%) | 58 (12.1%) | |
| APGAR in 5th minute <7 | 0 (0%) | 2 (0.4%) | - |
| Cesarean section | 156 (36.0%) | 226 (47.2%) | 0.001 |
| GH | 41 (9.5%) | 72 (15.0%) | 0.011 |
| PE | 9 (2.1%) | 15 (3.1%) | 0.321 |
| GDM-1 | 38 (8.8%) | 87 (18.2%) | <0.001 |
| GDM-2 | 8 (1.8%) | 13 (2.7%) | 0.384 |
* The Mann–Whitney U test was used for comparisons of continuous variables, the Cochran–Armitage test was used to detect a trend, and for binomial categories the Pearson chi-square test (or Fisher exact test when Cochran assumption was not met) was used (p-value < 0.05 was assumed to be significant); # For available data. Underweight: BMI <18.5 kg/m2; normal BMI: 18.5–24.9 kg/m2; overweight: BMI 25–29.9 kg/m2; obesity: BMI ≥30 kg/m2; IUGR: intrauterine growth restriction; the APGAR score evaluates an appearance, pulse, grimace, activity, and respiration; GH: gestational hypertension; PE: preeclampsia; GDM: gestational diabetes mellitus (treated with a diet (-1); with insulin therapy (-2)).