Nadine Peacock, an associate professor of community health sciences at the University of Illinois at Chicago, said because more women report being sexually active long before they are ready to have children means women spend more of their reproductive lives in need of birth control than in generations past.
"The widening income gap in unintended pregnancies and births reflect underlying disparities in health care in general, which in turn reflect broad social inequities in our society," she said.
Doctors say whether a baby is planned or not has important consequences for the health of the mother and the child. Mothers who have unplanned pregnancies are more likely to get little to no prenatal care, smoke cigarettes during their pregnancy and to decline to breastfeed, a practice known to have health benefits for mother and baby. Unintended babies also tend to have lower birth weight.
The costs to the nation's health care system are also tremendous. Two recent studies both estimated that the cost of prenatal care, delivery and care of unintended babies in the first year of life comes to about $11 billion each year.
"It will be interesting to see whether providing more access to health care [through the Affordable Care Act] changes these numbers for the next time this study result is released," Kingsberg said.