Table 1:
Descriptive statistics
| Full sample | Sibling sample | |||
|---|---|---|---|---|
|
|
||||
| N | % | N | % | |
|
| ||||
| Outcomes | ||||
| NAS diagnosis (narrow) | 4,284 | 1.60% | 2,137 | 4.7%*** |
| Suspected NAS (broad) | 8,792 | 3.40% | 3,637 | 8.0%*** |
| Low birthweight | 22,872 | 8.80% | 5,139 | 11.3%*** |
| Preterm | 27,157 | 10.50% | 5,996 | 13.2%*** |
| Small for gestational age | 31,055 | 12.00% | 6,194 | 13.6%*** |
| Five-minute APGAR score <7 | 6,415 | 2.50% | 1,139 | 2.50% |
| CPS investigation in 7 days | 3,721 | 1.40% | 1,383 | 3.0%*** |
| NICU admission | 22,724 | 9.80% | 5,025 | 12.5%*** |
| Prenatal and Birth Characteristics | ||||
| Received prenatal care T1 | 176,489 | 70.70% | 30,547 | 70.2%** |
| Infant died within 12 months | 1,790 | 0.70% | 495 | 1.1%*** |
| Male | 132,967 | 51.20% | 23,229 | 51.10% |
| Birth order | ||||
| First | 82,949 | 32.0% | 7,805 | 17.2%*** |
| Second | 75,730 | 29.2% | 12,496 | 27.5%*** |
| Third | 50,596 | 19.5% | 10,893 | 24.0%*** |
| Fourth or higher | 50,024 | 19.3% | 14,211 | 31.3%*** |
| Plural birth | 7,431 | 2.90% | 1,882 | 4.1%*** |
| Quarter of birth | ||||
| Q1 (Jan – Mar) | 64,521 | 24.80% | 11,451 | 25.20% |
| Q2 (Apr – Jun) | 64,491 | 24.80% | 11,208 | 24.70% |
| Q3 (Jul – Sep) | 67,845 | 26.10% | 11,765 | 25.90% |
| Q4 (Oct – Dec) | 62,866 | 24.20% | 11,028 | 24.30% |
| Mother Demographic Characteristics | ||||
| Mother’s residence at birth | ||||
| Rural | 64,994 | 25.0% | 11,482 | 25.3% |
| Maternal age | ||||
| < 22 | 56,542 | 21.80% | 9,093 | 20.0%*** |
| 22-30 | 143,989 | 55.40% | 27,770 | 61.1%*** |
| 31+ | 59,192 | 22.80% | 8,589 | 18.9%*** |
| Mother’s race/ethnicity | ||||
| Non-Hispanic White | 139,882 | 54.40% | 24,898 | 55.2%*** |
| Non-Hispanic Black | 51,389 | 20.00% | 10,973 | 24.3%*** |
| Hispanic | 39,516 | 15.40% | 5,158 | 11.5%*** |
| Other | 25,688 | 10.00% | 3,957 | 8.8%*** |
| Graduated HS | 208,530 | 80.30% | 34,713 | 76.4%*** |
| Married | 83,176 | 32.00% | 11,957 | 26.3%*** |
| Maternal morbidities | ||||
| Chronic diabetes | 3,113 | 1.2% | 614 | 1.4%*** |
| Chronic hypertension | 6,243 | 2.4% | 1,366 | 3.0%*** |
| GDM | 16,835 | 6.5% | 2,659 | 5.9%*** |
| Gestational hypertension | 14,757 | 5.7% | 2,348 | 5.2%*** |
| Mother smoking | 83,722 | 35.1% | 18,578 | 44.2%*** |
|
| ||||
| N | 259,723 | 45,452 | ||
Note: Data are from the 2010 –2019 birth cohorts in Wisconsin’s BD4LK linked administrative data. The full sample includes all Medicaid-enrolled live births in Wisconsin matched to birth records and Medicaid claims for mothers and infants. The sibling sample includes only continuously enrolled mothers with more than one child born in the same period. NAS = neonatal abstinence syndrome, CPS = child protective services, NICU = neonatal intensive care unit, T = trimester, HS = high school, and GDM = Gestational diabetes mellitus.