Table 1. Characteristics of stillbirth and live birth pregnancies.

Category	Characteristica	Stillbirth	Live Birth	p-Valueb
	Weighted sample size, number c	528	1,382
Mother	Maternal age at delivery, years			0.50
	Median	26	26
	Interquartile range	21 to 32	22 to 31
	Paternal age at delivery, years			0.02
	Median	28	29
	Interquartile range	23 to 34	24 to 34
	Maternal race/ethnicity, percent			<0.001
	Non-Hispanic white	34	46
	Non-Hispanic black	23	11
	Hispanic	38	36
	Other	6	8
	BMI, percent			0.003
	<18.5	4	3
	18.5–24.9	40	50
	25–29.9	26	23
	30–34	15	12
	≥35	16	11
	Maternal education, grade, percent			<0.001
	0–11	24	19
	12	31	26
	≥13	45	55
	Marital status, percent			<0.001
	Not married	26	15
	Cohabiting	26	24
	Married	48	60
	Insurance, percent			0.02
	No insurance	5	4
	Any public/private assistance	55	49
	VA/commercial health insurance/HMO	40	47
	Family income last 12 mo, percent			0.13
	Only public/private assistance	9	6
	Assistance and personal income	38	38
	Only personal income	53	56
	Blood type, percent			0.31
	A	31	34
	B	14	11
	O	51	51
	AB	4	3
	Rh negative, percent	9	11	0.20
	Smoking status, percent d			0.003
	Did not smoke	79	86
	<10 cigarettes/day	11	7
	≥10 cigarettes/day	10	7
	Alcohol consumption, percent d			0.60
	Did not drink	58	58
	Drank, no bingeing	21	23
	Binged	21	19
	Lifetime drug use, percent			0.03
	Never	66	69
	Ever, without addiction	29	28
	Ever, with addiction	5	2
	Medical history, percent
	Hypertension	11	5	<0.001
	Diabetes	5	2	<0.001
	Seizure disorder	3	2	0.23
	Pregnancy history, percent			<0.001
	Nulliparous; never pregnant or only elective terminations	36	30
	Nulliparous with previous losses	11	5
	Multiparous with no previous losses at <20 wk or stillbirths	31	46
	Multiparous with no stillbirth but previous losses at <20 wk	14	17
	Multiparous with stillbirth	7	2
Infant	GA, weeks e			<0.001
	Median	28	39
	Interquartile range	23 to 36	38 to 40
	GA category, percent			<0.001
	20–23 wk	33	<1
	24–27 wk	17	<1
	28–31 wk	11	1
	32–36 wk	21	9
	37+ wk	18	89
	Birth weight, grams			<0.001
	Median	992	3,317
	Interquartile range	454 to 2,468	2,978 to 3,628
	Male sex, percent	52	50	0.55
	Congenital anomaly, percent	13	3	<0.001

^aInformation was missing as follows (unweighted missing n for stillbirths and live births, respectively): paternal age (44 and 98), maternal race/ethnicity (1 stillbirth), BMI (21 and 42), maternal education (36 and 82), marital status (34 and 76), insurance (3 and 4), family income (40 and 90), blood type (5 and 6), Rh factor (2 and 6), cigarette smoking (34 and 78), alcohol consumption (37 and 81), drug use (38 and 91), hypertension (2 and 5), diabetes (1 and 5), seizure disorder (2 and 6), male sex (5 and 2).

Percentages may not sum to 100 because of rounding.

^b p-Value for a difference between stillbirths and live births by the median test (continuous variables) or the Wald chi-square test (categorical variables).

^cAnalysis weights that accounted for the basic study design plus other aspects of the sampling were used.

Unweighted sample sizes were 527 stillbirths and 1,821 live births.

^dAverage number of cigarettes smoked per day during the 3 mo prior to pregnancy or alcohol consumption during the 3 mo prior to pregnancy.

Drank without bingeing was defined as 0–6 drinks in a typical week and no occasion where four or more drinks were consumed in a single time period (“binge”). Bingeing was defined as at least one binge and/or seven or more drinks in a typical week.

^eGA at death (stillbirths) or delivery (live births) by the SCRN algorithm [17].

HMO, health maintenance organization; VA, Veterans Affairs.