Table 1.
Characteristics of the 410 mother–newborn pairs in present study
| Variables | Mean ± SD/ Median (IQR)/ Number (%) |
|---|---|
| Infant sex | |
| Male | 206 (50.2) |
| Female | 204 (49.8) |
| Gestational age (weeks) | 39.4 ± 1.2 |
| Maternal age at delivery(years) | 29.2 ± 3.4 |
| Education | |
| Junior school or below | 28 (6.8) |
| High school | 69 (16.8) |
| College or above | 313 (76.4) |
| Passive smoking during pregnancy | |
| Yes | 133 (32.4) |
| No | 277 (67.6) |
| Prepregnancy BMI (kg/m2) | 21.2 ± 3.0 |
| Parity | |
| Primiparous | 339 (82.7) |
| Multiparous | 71 (17.3) |
| Hypertensive disorders in pregnancy | |
| Yes | 12 (2.9) |
| No | 398 (97.1) |
| Gestational diabetes mellitus | |
| Yes | 41 (10.0) |
| No | 369 (90.0) |
| Relative cord blood TL | 0.74 (0.56–0.92) |
Data presented as mean ± SD for normally distributed data, or median (IQR) for skewed distributed data, or numbers (percentage) for categorical data