Table 4

a – Odds ratios (OR) and 95% confidence intervals (CI) for association of inadequate/no prenatal care with preterm birth (< 37 completed weeks gestation)*b – Odds ratios (OR) and 95% confidence intervals (CI) for association of inadequate/no prenatal care with low birth weight (<2500 grams)*c – Odds ratios (OR) and 95% confidence intervals (CI) for association of inadequate/no prenatal care with small-for-gestational age (birth weight < 10th percentile for gestational age)*
a – Odds ratios (OR) and 95% confidence intervals (CI) for association of inadequate/no prenatal care with preterm birth (< 37 completed weeks gestation)*
Index
 Unadjusted OR
 95% CI
 Adjusted OR**
 95% CI
APNCU Index
 1.3
 1.2 – 1.5
 1.2
 1.1 – 1.3
R-GINDEX
 1.1
 1.0 – 1.2
 1.0
 0.9 – 1.1
b – Odds ratios (OR) and 95% confidence intervals (CI) for association of inadequate/no prenatal care with low birth weight (<2500 grams)*
Index
 Unadjusted OR
 95% CI
 Adjusted OR**
 95% CI
APNCU Index
 1.4
 1.3 – 1.6
 1.3
 1.2 – 1.5
R-GINDEX
 1.2
 1.1 – 1.4
 1.1
 1.0 – 1.3
c – Odds ratios (OR) and 95% confidence intervals (CI) for association of inadequate/no prenatal care with small-for-gestational age (birth weight < 10th percentile for gestational age)*
Index
 Unadjusted OR
 95% CI
 Adjusted OR**
 95% CI
APNCU Index
 1.5
 1.4 – 1.6
 1.4
 1.3 – 1.5
R-GINDEX
 1.4
 1.3 – 1.5
 1.4
 1.3 – 1.5

* Inadequate/no prenatal care was compared to the reference group of all other types of care (intermediate, adequate and intensive).

**Controlling for maternal age and parity, and adjusting for within-mother dependency. Maternal age was studied using categories of <20 years, 20–24 years, 25–29 years, 30–34 years, and 35+ years, with 35+ years as the reference group. Parity was studied using categories of first birth, 2nd-3rd birth and 4 or more births, with first birth as the reference group.

Heaman et al. BMC Pregnancy and Childbirth 2008 8:15   doi:10.1186/1471-2393-8-15