Table 1.

Baseline demographic characteristics of the study population.

Characteristic	Incidence (n=149)
Maternal age, years (mean ± standard deviation)	28.7 ± 6.0
Maternal age >35 years old (%)	33.5
Body mass index (mean ± standard deviation)	33.4 ± 8.8
Black race (%)	51.2
Preeclampsia or gestational hypertension (%)	26.7
Prior preterm delivery (%)	19.7
Preterm delivery <37 weeks (%)	29.5
Preterm delivery <34 weeks (%)	16.1
Preterm delivery <28 weeks (%)	6.0
Preterm premature rupture of membranes(%)	14.9
Vaginal delivery (%)	55.0