Table 1.
Maternal Characteristics by Urban–Rural Classification Scheme for Counties: U.S. Birth Certificate Data, 2010–2018
| Maternal characteristics at delivery | Total | 6-Level Urban-Rural Classification Scheme % of total |
|||||
|---|---|---|---|---|---|---|---|
| Large central metro | Large fringe metro | Medium metro | Small metro | Micropolitan | Non-core | ||
| All births in the U.S., n | 35,397,658 | 33.0 | 23.4 | 21.0 | 9.0 | 8.2 | 5.4 |
| Births in reporting states,a n | 32,555,153 | 33.8 | 22.9 | 20.8 | 8.9 | 8.3 | 5.3 |
| Among reporting states | |||||||
| Maternal age at birth, years | 32,555,153 | ||||||
| <20 | 2,147,632 | 6.0 | 4.9 | 7.3 | 7.7 | 9.0 | 9.3 |
| 20–24 | 7,083,520 | 19.2 | 17.5 | 23.9 | 26.0 | 28.7 | 30.0 |
| 25–29 | 9,383,286 | 26.9 | 28.0 | 30.2 | 31.4 | 31.0 | 31.3 |
| 30–34 | 8,721,104 | 28.7 | 30.6 | 25.1 | 23.5 | 21.0 | 20.0 |
| 35–39 | 4,229,385 | 15.4 | 15.4 | 11.1 | 9.5 | 8.5 | 7.8 |
| ≥40 | 990,226 | 3.8 | 3.6 | 2.4 | 2.0 | 1.8 | 1.7 |
| Maternal race/ethnicity | |||||||
| Hispanic | 7,696,290 | 32.7 | 19.1 | 24.7 | 15.9 | 14.3 | 9.6 |
| Non-Hispanic White | 17,174,129 | 35.3 | 57.9 | 55.9 | 66.7 | 72.0 | 75.9 |
| Non-Hispanic Black | 4,683,992 | 19.0 | 14.1 | 12.6 | 11.6 | 8.0 | 8.3 |
| Otherb | 2,992,797 | 13.1 | 8.9 | 6.8 | 5.9 | 5.6 | 6.2 |
| Marital status | |||||||
| Not married, no paternity acknowledgement | 3,891,990 | 12.4 | 9.3 | 12.5 | 13.3 | 13.4 | 14.1 |
| Not married, paternity acknowledgement | 8,889,338 | 27.6 | 24.4 | 28.1 | 28.0 | 30.2 | 29.2 |
| Married | 18,847,431 | 54.8 | 64.7 | 56.7 | 57.7 | 56.0 | 56.4 |
| Maternal educational attainment | |||||||
| No high school diploma or GED | 4,970,573 | 16.7 | 11.4 | 16.1 | 14.8 | 17.1 | 17.6 |
| High school diploma or GED | 8,122,282 | 23.7 | 21.6 | 25.7 | 27.7 | 30.0 | 31.9 |
| Some college | 9,284,067 | 25.0 | 27.7 | 30.8 | 32.1 | 32.5 | 32.9 |
| Bachelor’s degree or higher | 9,720,068 | 32.6 | 37.7 | 26.4 | 24.6 | 19.7 | 16.8 |
| Expected source of payment for delivery | |||||||
| Medicaid | 13,997,365 | 44.6 | 34.2 | 44.7 | 45.1 | 49.0 | 51.2 |
| Private | 15,413,565 | 46.2 | 57.8 | 44.1 | 44.3 | 40.3 | 38.4 |
| Self-pay | 1,333,698 | 4.6 | 3.3 | 3.8 | 3.7 | 4.9 | 5.3 |
| Other | 1,410,035 | 3.7 | 3.1 | 6.2 | 5.6 | 4.7 | 3.8 |
| WIC use during pregnancy | |||||||
| Yes | 13,659,406 | 43.3 | 31.8 | 44.7 | 45.0 | 48.8 | 50.3 |
| No | 18,265,233 | 55.2 | 65.3 | 53.6 | 52.9 | 49.5 | 47.6 |
| Pre-pregnancy BMI | |||||||
| Underweight | 1,146,154 | 3.8 | 3.2 | 3.5 | 3.4 | 3.6 | 3.5 |
| Normal | 14,213,097 | 46.0 | 44.5 | 42.6 | 41.4 | 40.3 | 38.8 |
| Overweight | 8,091,559 | 24.5 | 25.1 | 25.3 | 25.0 | 24.9 | 24.8 |
| Obese | 7,917,842 | 21.8 | 22.8 | 25.7 | 27.3 | 28.7 | 30.1 |
| Pregnancy smoking statusc | |||||||
| No | 28,788,307 | 93.6 | 88.2 | 88.1 | 83.6 | 80.5 | 78.5 |
| Yes | 2,477,793 | 3.5 | 6.2 | 8.5 | 11.7 | 15.5 | 17.3 |
| Unknown/not stated | 1,289,053 | 3.0 | 5.6 | 3.4 | 4.7 | 4.0 | 4.2 |
| First trimester prenatal care initiation | |||||||
| No | 7,609,420 | 23.2 | 21.1 | 24.2 | 24.4 | 25.6 | 26.2 |
| Yes | 23,809,149 | 73.0 | 74.4 | 73.0 | 72.6 | 72.3 | 70.9 |
| Unknown/not stated | 1,081,024 | 3.7 | 4.2 | 2.7 | 2.9 | 1.9 | 2.5 |
| County-level characteristics | |||||||
| County of residence, percentage below poverty thresholdd | |||||||
| <10% | 5,443,385 | 4.7 | 49.4 | 10.1 | 8.4 | 7.5 | 6.4 |
| 10%–19% | 22,041,463 | 80.4 | 48.0 | 70.3 | 72.2 | 65.2 | 58.3 |
| 20%–29% | 4,507,466 | 13.7 | 2.6 | 16.5 | 18.5 | 23.4 | 30.0 |
| ≥30% | 562,822 | 1.2 | 0.0 | 3.1 | 0.9 | 3.9 | 5.2 |
| County overdose death rate per 100,000 population,e mean | 32,555,153 | 15.8 | 16.7 | 17.4 | 15.8 | 16.9 | 17.3 |
Notes: Births in reporting states per year: 2010=3,055,884; 2011=3,267,934; 2012=3,412,436; 2013=3,548,525; 2014=3,837,663; 2015=3,839,624; 2016=3,945,875; 2017=3,855,500; 2018=3,791,712. Missing and unknown values (all <4%) were excluded from display in the table for the following characteristics: race/ethnicity (<0.1%, n=7,945), marital status (2.8%, n=926,394, with nearly all missing values from California starting in 2017), educational attainment (1.4%, n=458,163), source of payment for delivery (1.3%, n=400,490), Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) use during pregnancy (1.9%, n=630,514), pre-pregnancy BMI (3.7%, n=1,186,501), first trimester of prenatal care (0.2%, n=55,560), and county of residence percentage poverty level (<0.1%, n=17).
States and Washington, District of Columbia, reporting maternal hepatitis C virus infection used the 2003 revised birth certificate for the entire reporting year (U.S. territories excluded). The number of areas using the revised birth certificate increased over time: 34 areas in 2010, 37 areas in 2011, 38 areas in 2012, 41 areas in 2013, 48 areas in 2014, 49 areas in 2015, and all 51 areas in 2016–2018. Overall, there were 55,568 births with missing information on maternal hepatitis C virus infection (decreased from 14,096 in 2010 to 3,121 in 2017); the remaining births had either N, Y, or U documentation. U documentation (n=117,032) indicated the individual hospital did not report maternal HCV infection status.
Includes Asian or Pacific Islander, American Indian or Alaska Native, Other, and Hispanic origin unknown or not stated; and unknown.
Smoking during any trimester of pregnancy.
Generated by merging restricted-use data files with Census Bureau data on percentage of families below the poverty threshold by county Federal Information Processing Standard Publication (FIPS) for mother’s county of residence at the time of birth.
Generated by merging restricted-use data files with vital records published data on overdose death rates by county Federal Information Processing Standard Publication (FIPS) for mother’s county of residence at the time of birth.
GED, general education diploma; WIC, Special Supplemental Nutrition Program for Women, Infants, and Children.