Table 1.
Maternal and pregnancy characteristics of the 4265 women enrolled in the Fetal Growth Longitudinal Study of the INTERGROWTH-21st Project who had crown–rump length measured between 9 + 0 and 13 + 6 weeks' gestation according to last menstrual period and a live singleton birth, in the absence of severe maternal conditions or congenital abnormalities detected by ultrasound or at birth
| Parameter | Value |
|---|---|
| Maternal age (years) | 28.3 ± 3.9 |
| Maternal height (cm) | 162.2 ± 5.8 |
| Paternal height (cm) | 174.4 ± 7.3 |
| Maternal weight (kg) | 61.2 ± 9.1 |
| Maternal body mass index (kg/m2) | 23.2 ± 3.0 |
| Gestational age at first visit (weeks) | 11.8 ± 1.4 |
| Formal education (years) | 15.0 ± 2.8 |
| Hemoglobin level before 15 weeks' gestation (g/dL) | 12.5 ± 1.1 |
| Married/cohabiting | 4150 (97.3) |
| Nulliparous | 2922 (68.5) |
| Spontaneous initiation of labor | 2826 (66.3) |
| Cesarean section | 1522 (35.7) |
| Preterm delivery (< 37 + 0 weeks' gestation) | 192 (4.5) |
| NICU admission > 1 day | 239 (5.6) |
| Neonatal mortality | 7 (0.2) |
| Newborn sex male | 2126 (49.8) |
| Birth weight (kg)* | 3.3 ± 0.4 |
| Newborn length (cm)* | 49.4 ± 1.9 |
| Newborn head circumference (cm)* | 33.9 ± 1.3 |
Data are given as mean ± SD or n (%).
* ≥ 37 + 0 weeks of gestation only. NICU, neonatal intensive care unit.