Table 1 Demographic data

 Maternal age, years (mean ± SD)

32.2 ± 5.5

 Parity, n (median [range])

1 [0–9]

 Gestational age at admission, weeks (mean ± SD)

26.8 ± 2.4

 Gestational age at delivery, weeks (mean ± SD)

28.2 ± 2.6

 Sonogram to delivery interval, days (median [range])

3 [0–14]

 Birth weight, grams (mean ± SD)

1154 ± 418

 Oligohydramnios (MVP < 2 cm), n(%)

279 (49.4)

 Male neonates, n(%)

317 (56.1)