Table 1 Characteristics of study population by GA at birth and selected maternal and neonatal variables
GA | total | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 |
|---|---|---|---|---|---|---|---|---|---|
n | 25312 | 276 | 457 | 801 | 1780 | 4189 | 6535 | 7218 | 4056 |
Maternal Characteristics | |||||||||
maternal age group, years <19 | 5.1 | 5.8 | 3.5 | 4.2 | 4.9 | 4.4 | 5.4 | 5.1 | 5.5 |
>34 | 12.9 | 13.8 | 15.3 | 17.7 | 16.1 | 15.1 | 12.4 | 11.4 | 11.2 |
primiparous, % | 38.1 | 44.2 | 39.6 | 36.6 | 35.7 | 32.5 | 35.1 | 39.4 | 46.8 |
caesarean section, % | 20.8 | 35.9 | 33.7 | 29.0 | 24.9 | 30.1 | 21.2 | 13.9 | 17.2 |
induced delivery, % | 26.8 | 26.8 | 35.2 | 35.0 | 33.7 | 34.8 | 22.1 | 16.4 | 39.1 |
multiple gestation, % | 2.2 | 23.6 | 21.9 | 11.7 | 8.0 | 2.7 | 0.3 | 0.2 | 0.0 |
maternal diabetes, % | 4.8 | 7.6 | 12.0 | 17.2 | 10.1 | 8.5 | 3.8 | 2.4 | 0.8 |
low SES, % | 32.4 | 35.9 | 37.2 | 39.3 | 36.8 | 33.6 | 31.8 | 31.2 | 30.4 |
breastfed, % | 81.6 | 68.8 | 69.4 | 73.9 | 79.2 | 80.5 | 81.3 | 83.2 | 85.3 |
rural, % | 44.2 | 34.8 | 42.2 | 41.3 | 39.6 | 43.3 | 42.9 | 47.8 | 44.3 |
Newborn Characteristics | |||||||||
male, % | 51.2 | 58.0 | 55.4 | 54.2 | 51.7 | 53.0 | 49.6 | 50.1 | 51.9 |
mean BW, grams (SD) | 2377 (460) | 2640 (534) | 2936 (530) | 3143 (480) | 3358 (479) | 3496 (459) | 3656 (463) | 3774 (469) | |
BW range, grams | 1184-3902 | 1216-4599 | 1420-5160 | 1172-5305 | 1610-6440 | 1703-6457 | 1349-5589 | 1438-5795 | |
Large for GA, % | 14.9 | 12.7 | 15.3 | 16.7 | 15.4 | 15.6 | 14.1 | 15.0 | 14.9 |
Small for GA, % | 7.5 | 7.3 | 8.5 | 8.9 | 7.5 | 7.3 | 8.0 | 7.0 | 7.2 |
resuscitation at birth, % | 7.6 | 31.2 | 20.1 | 12.2 | 9.2 | 7.3 | 5.5 | 6.7 | 7.9 |
median LOS, days (range) | 2 (1-168) | 13 (1-90) | 6 (1-66) | 3 (1-71) | 2 (1-103) | 2 (1-168) | 2 (1-93) | 2 (1-55) | 2 (1-42) |
major congenital anomaly, % | 2.5 | 10.1 | 5.7 | 5.6 | 3.2 | 3.1 | 2.1 | 1.7 | 2.1 |