Table 2.
Study population characteristics (n = 178).
| Characteristic | Mean ± SD, geometric mean (25th–75th percentile) or n(%) | |
|---|---|---|
| Maternal | ||
| Age (years) | 29.1 ± 4.9 | |
| < 20 | 6 (3.4) | |
| 20–29 | 88 (49.4) | |
| 30–35 | 65 (36.5) | |
| ≥ 35 | 19 (10.7) | |
| Socioeconomic status | ||
| Low | 28 (15.7) | |
| Middle | 58 (32.6) | |
| High | 92 (51.7) | |
| Smoking | ||
| Never | 126 (70.8) | |
| Before pregnancy | 24 (13.5) | |
| Before and during pregnancy | 28 (15.7) | |
| Cigarettes/day | ||
| 0 | 124 (75.6) | |
| 1 to 10 | 28 (17.1) | |
| ≥ 11 | 12 (7.3) | |
| Pack-years of ever smokers | 6.1 ± 5.1 | |
| Pregestational BMI (kg/m2) | 24.3 ± 4.8 | |
| Net weight gain (kg) | 14.5 ± 6.5 | |
| Parity | ||
| 1 | 101 (56.8) | |
| 2 | 57 (32.0) | |
| ≥ 3 | 20 (11.2) | |
| Daily apparent temperature (°C) | 8.4 ± 1.6 | |
| Newborn | ||
| Gestational age (weeks) | 39.2 (39–40) | |
| Preterm delivery (< 37 weeks) | ||
| Yes | 7 (3.9) | |
| No | 171 (96.1) | |
| Sex | ||
| Male | 82 (46.1) | |
| Female | 96 (53.9) | |
| Ethnicity | ||
| European | 156 (87.6) | |
| Non-European | 22 (12.4) | |
| Season | ||
| Cold period | 104 (58.4) | |
| Warm period | 74 (41.6) | |
| Apgar score | ||
| 1 min | 8.4 (8–9) | |
| 5 min | 9.5 (9–10) | |
| Neonate birth weight (g) | 3,403 ± 386.7 | |
| Neonate length (cm) | 50 (49–51) | |
| Placental mtDNA contenta | 1.03 (0.6–1.63) | |
| Umbilical cord mtDNA contentb | 1.02 (0.75–1.30) | |
| White blood cells (× 10.e3/μL) | 15.3 ± 4.6 | |
| Neutrophils (%) | 52.3 ± 8.5 | |
| Platelets (× 10.e3/μL) | 289.4 ± 95.4 | |
| Not normally distributed values are presented as geometric means with 25–75th percentile. mtDNA content is determined as mtDNA copy number (mean of MTF3212/R3319 and MT-ND1) normalized to nDNA copy number (mean of RPLP0, ACTB and HBB). aData available for 174 subjects. bData available for 176 subjects. | ||