Timing of incarceration during pregnancy and birth outcomes: exploring racial differences

To examine whether there are racial differences in the relation between the timing of incarceration during pregnancy and birth outcomes among incarcerated pregnant women.

We examined the medical records associated with 360 infants born to pregnant inmates in Texas state prisons between January 1, 2002 and December 31, 2004. Weighted linear regression was used, within racial strata, to model gestational age at delivery, and infant birth weight, respectively, as functions of gestational age at maternal admission to prison. Models were adjusted for maternal age; gravidity; educational attainment; history of tobacco, substance, and alcohol use and the presence of any maternal chronic disease.

Among Whites there was a 360.8 g lower mean birth weight for infants born to women incarcerated during weeks 14-20 relative to infants born to women incarcerated during weeks 1-13 (p < 0.10). Among Blacks and Hispanics, incarceration after the first trimester was not associated with a significant decrease in infant birth weight relative to incarceration during the first trimester. White women entering prison during the first trimester delivered infants at higher gestational ages than White women entering in the second trimester but the opposite was the case for Hispanics.

The association between the quantity of exposure to prison during pregnancy and birth outcomes appears to be different for Blacks, Whites, and Hispanic women. Future studies of the effect of incarceration on pregnancy outcomes should attempt to uncover potential racial differences in trends by obtaining racially stratified results or by assessing interaction with race.