Federal funding in the form of Medicaid is used to pay for 45 percent of all births in the US, according to new research published in the journal Women's Health Issues, which analyzed the 4 million births that took place in the nation in 2010.

According to the researchers, who gathered data from all 50 states, the Medicaid information will allow health professionals and researches to gauge the impact of health care reform on maternal and child health.

Lead author of the study Anne Markus, an associate professor of health policy at the George Washington University School of Public Health and Health Services, said that as some states expand their Medicaid programs under the Obama administration's Affordable Care Act it may lead to improved women's and maternity heath care practices and perhaps result in better health outcomes.

"As states expand coverage, low-income women of childbearing age will be able to obtain more continuous coverage before and between pregnancies," said Markus. "Now, for the first time, researchers will have a comprehensive baseline that will help them determine how increased access to services might change pregnancies and ultimately birth outcomes."

Prior to Markus and her colleagues' research, a comprehensive assessment of Medicaid data was unavailable. By collecting and analyzing data between 2008 and 2010, the research team found that was a four percent increase the proportion of Medicaid-assisted births in the two year span.

The researchers hope their work will enable a future assessment of the number of Medicaid-assisted births and health coverage associated with Medicaid. For instance, states that expand their Medicaid coverage to before and after birth could find that the expansion leads to fewer complicated pregnancies and more healthy, full-term babies.

"About half a million babies are born prematurely in the United States every year," said March of Dimes President Dr. Jennifer L. Howse. "Some of these preterm births could be prevented with the appropriate care provided at the right time. Babies born premature are at risk for lifelong health problems and often require care in a hospital's neonatal intensive care unit. This study gives us a critical baseline to help chart the progress of health reform as it affects maternal and child health."

The study also found:

  • The percentage of births paid for by Medicaid varied substantially among states. For example, just one quarter of births in Hawaii were financed by Medicaid compared to nearly 70 percent in Louisiana.
  • States in the northeastern and northwestern United States have the lowest proportion of births financed by Medicaid. For example, Massachusetts and New Hampshire reported fewer than 30 percent of births funded by Medicaid, and Washington State reported 39 percent.
  • Southern states tend to have the highest Medicaid coverage: For example, Arkansas, Louisiana, Mississippi, the District of Columbia and Puerto Rico each reported 60 percent or more of all births financed by Medicaid in 2010.