Table 1.
Characteristics of 46,610 mother-child dyads
| Characteristics | Mean (SD) | n (%) |
|---|---|---|
| Maternal age | 30.2 (4.7) | |
| < 35 years old | 39,019 (83.7) | |
| Primiparous | 19,534 (41.9) | |
| Hypertensive disorders of pregnancy | 1493 (3.2) | |
| Gestational diabetes | 6787 (14.6) | |
| Maternal carrier of HBVa | 2189 (7.5) | |
| Sex of newborns (Male) | 24,927 (53.5) | |
| Gestational age at birth, weeks | 39.0 (1.5) | |
| Preterm birth | 2590 (5.6) | |
| Birth weight of newborns, kg | 3.2 (0.4) | |
| Birth weight for gestational age of newborns, Z-scoreb | 0.0 (0.9) | |
| Small for gestational agec | 3265 (7.0) | |
| Head circumference of newborns, cm | 33.3 (1.3) | |
| Head circumference of newborns, Z-scoreb | −0.3 (1.0) | |
| < −3.0 | 154 (0.3) | |
| ≥ −3.0 & < −2.0 | 1777 (3.8) | |
| BWHC Z-score differenced | −0.3 (0.8) | |
| < −3.0 | 58 (0.1) | |
| ≥ −3.0 & < −2.0 | 987 (2.1) |
HBV Hepatitis B Virus, SD Standard deviation, BWHC Birth weight and head circumference of newborns
aAnalyzed among the births born in two campuses of Guangzhou Women and Children’s Medical Center (n = 29,493)
bCalculated according to the INTERGROWTH-21st standards
cDefined as gestational age and sex-adjusted birth weight < 10th percentile based on the INTERGROWTH-21st newborn size standard
dDefined as the difference between head circumference Z-score and birth weight Z-score of newborns