Table 1 Characteristics of singleton births in study sample compared with overall population of singleton births at 37-44 weeks of gestational age, California (1996-2006).
From: Ambient air pollution exposure and full-term birth weight in California
| Â | Total Eligible Singleton Births (n = 4,776,090) | Study Sample (n = 3,545,177) |
|---|---|---|
low birth weight (<2,500 grams) | 2.3% | 2.3% |
maternal age (years) | Â | Â |
9 to 14 | 0.1% | 0.2% |
15 to 19 | 9.9% | 10.2% |
20 to 34 | 74.2% | 74.3% |
35 to 49 | 15.8% | 15.4% |
educational attainment | Â | Â |
none to 11th grade | 30.2% | 31.5% |
12th grade | 27.6% | 27.6% |
1-3 years college | 19.8% | 19.4% |
4+ years college | 22.4% | 21.4% |
marital status | Â | Â |
married | 42.8% | 42.0% |
not married | 22.5% | 23.7% |
not on form | 27.9% | 27.4% |
missing | 6.8% | 6.9% |
maternal race/ethnicity | Â | Â |
Hispanic | 49.6% | 51.5% |
Black (non-Hispanic) | 5.8% | 6.3% |
American Indian/Alaska Native (non-Hispanic) | 0.4% | 0.3% |
Asian Pacific Islander (non-Hispanic) | 11.9% | 12.0% |
Other Race (non-Hispanic) | 0.0% | 0.0% |
White (non-Hispanic) | 32.2% | 29.6% |
missing | 0.1% | 0.1% |
maternal birthplace | Â | Â |
Mexico | 27.6% | 28.6% |
other or unknown foreign country | 18.5% | 19.2% |
US and her territories | 53.8% | 52.1% |
missing | 0.1% | 0.1% |
parity | Â | Â |
first live birth | 39.5% | 39.7% |
maternal risk factors | Â | Â |
anemia, diabetes, hypertension and/or herpes | 4.5% | 4.4% |
none of the above | 86.1% | 86.4% |
missing | 9.4% | 9.2% |
Kotelchuk index | Â | Â |
no prenatal care | 1.6% | 1.8% |
inadequate | 9.0% | 9.0% |
intermediate | 11.8% | 11.7% |
adequate | 44.1% | 43.8% |
more than adequate | 33.5% | 33.7% |
insufficient information | 0.1% | 0.1% |