Table 1.

Baseline characteristics of enrolled infants (N = 1255)

Characteristics	Results
At birth
Male infant, n (%)
Male	683 (54.4)
Female	572 (45.6)
Gestational period (week)	39.3 ± 1.4
Birth weight (g)	3396.1 ± 462.6
Birth length (cm)	50.1 ± 1.2
Apgar score (1 min)	8.7 ± 0.7
Delivery mode, n (%)
Vaginal	636 (50.7)
Cesarean section	619 (49.3)
At 7–14 months follow-up
Feeding pattern, n (%)
Breast milk/ Mix feeding	754 (60.1)
Formula feeding	501 (39.9)
PVST interval (month), n (%)
1–	191 (15.2)
2–	278 (22.2)
3–	220 (17.5)
4–	141 (11.2)
5–	95 (7.6)
6–	136 (10.8)
7–8	194 (15.5)