Epidemiology of maternal injuries during pregnancy in a population-based study, 1997-2005

Maternal injuries during pregnancy are common and can cause adverse pregnancy outcomes. We sought to describe factors related to injury during pregnancy.

We analyzed data from the National Birth Defects Prevention Study (NBDPS), a population-based, case-control study of birth defects in 10 U.S. states. We estimated the proportion of control mothers, a random sample of mothers delivering infants without major birth defects in the study regions, who reported an injury during pregnancy. We assessed associations with maternal and paternal characteristics using logistic regression to estimate adjusted odds ratios (aOR) and 95% confidence intervals (CI).

Between October 1997 and December 2005, 490 (7.4%) of 6609 mothers reported 527 injuries during pregnancy. Falls caused over half of reported injuries during pregnancy (51.6%), and 9.5% of reported injuries were intentionally inflicted. Mothers who reported an injury during pregnancy were more likely to be aged <18 years vs. 18-29 years (aOR 2.84, 95% CI 1.54-5.23) and less likely to be aged ≥30 years (aOR 0.67, 95% CI 0.51-0.89). They were more likely to use alcohol during pregnancy (aOR for nonbinge drinking 1.38, 95% CI 1.05-1.81), to smoke during pregnancy (aOR 1.37, 95% CI 1.02-1.85), to have epilepsy (aOR 3.31, 95% CI 1.48-7.38), and to be employed (aOR 1.44, 95% CI 1.08-1.93) than mothers who did not report an injury.

We identified several factors associated with maternal injury during pregnancy, an important step in identifying women who may be at higher risk and in designing interventions to prevent injuries during pregnancy.