TABLE 3.

Weighted Parental and Infant Characteristics and Birth Outcomes for Births to White Women, by Paternal Race/Ethnicity: National Center for Health Statistics Linked Birth and Infant Death File, 2001

	Black (Ref)	White	Mexican	American Indian	Puerto Rican	Central/South Americana	Unreported
Effective sample size,b No.	42 839	662 700	28 249	8 088	8 769	4 506	42 719
Maternal characteristics
Married, %	44.5	44.4	45.2	46.2	45.9	47.4	44.2
Maternal age, y, %
< 20 y	13.9	13.9	14.4	15.3	14.0	14.8	14.1
20–34 y	78.0	77.6	77.2	76.2	77.0	76.2	77.7
> 34 y	8.2	8.6	8.4	8.5	9.0	9.0	8.2
Maternal education, y, %
≤ 9 y	5.3	5.4	5.7	6.0	5.8	5.9	5.8
10–12 y	55.3	55.0	55.8	56.0	55.6	53.2	56.1
> 12 y	39.4	39.6	38.5	38.0	38.7	40.9	38.1
US born, %	95.6	95.6	95.5	96.4	95.4	95.2	95.4
No. of prenatal care visits, mean	11.6	11.2	11.2	11.2	11.2	11.2	11.2
Adequacy of care,c %
Adequate	71.9	72.2	72.0	71.3	71.4	71.9	71.6
Intermediate	19.1	19.0	19.5	20.0	19.3	19.2	23.4
Inadequate	4.8	4.8	4.8	4.7	4.6	4.8	5.1
Tobacco use, %	23.1	22.9	22.6	24.6	22.6	20.1	20.3
Alcohol use, %	0.9	0.9	0.9	1.1	1.1	1.1	1.0
Paternal characteristic
Paternal age, y, %
< 20 y	5.5	5.6	6.0	6.3	6.0	5.7	…
20–34 y	72.6	72.7	73.4	73.3	73.4	74.1	…
> 34 y	21.9	21.7	20.6	20.4	20.6	20.2	…
Infant characteristics
Gestational age, weeks, mean	38.9	38.8	38.8	38.8	38.9	38.9	38.8
Male, %	50.7	51.3	51.1	50.6	51.6	51.7	51.0
Live-birth order, %
First live birth	40.0	40.6	40.4	41.7	42.1	42.9	40.0
Second live birth	32.2	32.0	31.5	31.3	31.2	31.5	31.8
Third live birth or beyond	27.8	27.5	28.1	27.0	26.7	25.6	28.2
Infant outcome, mean
Birthweight, g	3343	3351	3319	3359	3323	3343	3316*
LBW rate (per 100)	6.26	6.07	6.10	5.46	5.88	6.09	6.85*
5-minute Apgar score	8.92	8.93	8.91	8.93	8.94	8.93	8.90
Infant mortality (per 1000)	7.07	6.44	5.41	6.12	4.33	6.25	7.81

Note. LBW = low birthweight. California data were excluded. For each infant in each comparison group (e.g., White mother–White father) propensity scores were estimated with a nonparametric regression technique and then were weighted based on the estimated propensity score to match the reference group (i.e., White–Black). In this approach, an individual more similar to those in the reference group receives a higher propensity score and, thus, higher weight. The propensity score estimation and weighting process were performed for each comparison group independently. Ellipses indicate that data are not applicable.

^aCentral or South American may include a couple of ethnicities depending on the definition of ethnicity. However, on October 30, 1997, the Office of Management and Budget published Standards for Maintaining, Collecting, and Presenting Federal Data on Race and Ethnicity,¹⁶ which allows federal agencies to collect information that reflects the increasing diversity of our nation's population stemming from growth in interracial marriages and immigration. With respect to ethnicity, the “Hispanic or Latino” category is defined as, “A person of Cuban, Mexican, Puerto Rican, South or Central American, or other Spanish culture or origin, regardless of race.”¹⁶ This subcategory of South or Central American has since been widely used in data collection and publications.

^bThe effective sample size is approximately the number of observations from a simple random sample needed to obtain an estimate with sampling variation equal to the sampling variation obtained with the weighted comparison observations. Therefore, the effective sample size gives an estimate of the number of comparison participants that are comparable to the target group.

^cAdequacy of prenatal care was coded according to standard methods to include the month prenatal care began, number of prenatal visits, and gestation period.

^*P < .01 (2-tailed t test).