Table I.

Clinical and demographic descriptors of cohort, stratified by couple race

	Female white/Male white n=129	Female white/Male black n=35	Female black/Male white n=12	Female black/Male black n=149	p
Maternal age, yrs Median (range)	25 (18–41)	23 (18–34)	23 (18–34)	25 (17–42)	0.23*
Gestational age at enrollment, wks Median (range)	8.5 (5–13)	10 (4–13)	8.5 (5–13)	8.5 (4–13)	0.52*
Less than high school education, n(%)	28 (21.7)	8 (22.1)	3 (25.0)	35 (23.5)	0.55#
Number of sexual partners in year prior to pregnancy Median (range)	1 (1–20)	1 (1–5)	1 (1–3)	1 (1–22)	0.80*
Number of sexual partners in 3 months prior to pregnancy Median (range)	1 (1–20)	1 (1–2)	1	1 (1–20)	0.80*
Times per week of vaginal intercourse in year prior to pregnancy Median (range)	2.5 (0–21)	3 (0–14)	4 (1–14)	3 (0–21)	0.65*
Times per week of vaginal intercourse in 3 months prior to pregnancy Median (range)	2.5 (0–21)	4 (0–14)	5 (1–14)	3 (0–20)	0.11*
Times per week of vaginal intercourse since pregnancy Median (range)	1 (0–21)	2 (0–7)	1.5 (0–7)	1 (0–7)	0.70*
Parity Median (range)	2 (1–7)	4 (1–8)	2 (1–6)	4 (1–13)	0.001*
Married N (%)	35 (27.3)	4 (11.8)	2 (16.7)	14 (9.4)	0.001#
Unemployed N(%)	60 (46.9)	17 (50.0)	6 (50.0)	82 (55.0)	0.58#
Smoker N(%)	78 (60.9)	20 (58.8)	4 (33.3)	69 (46.6)	0.05#

^*Kruskal-Wallis test

^#χ² test