A growing number of pregnant women are opting to have induced labor, according to a 12-year study of women in Illinois.

“Almost 25 or 30 percent of women are choosing to have their labor timed and started as opposed to starting spontaneously,” said lead study author Karna Murthy, M.D. He added, however, that “the consequences are not clear.”

Murthy and colleagues at the Feinberg School of Medicine at Northwestern University analyzed state data from the National Center for Health Statistics spanning 1991 to 2003 in an attempt to understand where increases in induction rates are occurring.

The study appears in the September issue of the journal Medical Care.

The data included 2.3 million women in Illinois delivering a single child during the 12-year period. In raw numbers, researchers found that induction rates nearly tripled from 106 per to 308 per 1,000 white women. The rates more than tripled for African-American women — from 63 to 223 per 1,000. For women in other ethnic groups, induction rates more than doubled, from 77 to 186 per 1,000 women.

Looking at the numbers from a different angle — and taking medical reasons for inducing labor into account — the trend toward higher induction rates was more pronounced in women who are not African-American.

Increases in a county’s population of pregnant white women raised the average induction rate in that county, as it did increases in women in other ethnic groups, except African-American.

William Rayburn, chair of the department of obstetrics and gynecology at University of New Mexico, has also researched induced labor rates. Although he hasn’t studied the difference between induction rates among women of different races, he suggested, “It is likely less of a racial issue and perhaps more of an issue as to where patients deliver and maybe the payer source.”

While the majority of inductions are done for medical reasons, Rayburn said that frequently, elective inductions “will be done for convenience reasons and it adds to the cost. When you are dealing with a group of patients who don’t have, let’s say, private insurance or private pay, there might be more of an effort by physicians to minimize cost.”

Economics aside, a low induction rate is better, according to Rayburn: “With induction there is greater risk of Caesarian [section delivery].”

Murthy K, et al. Racial disparities in term induction of labor rates in Illinois. Medical Care 46(9), 2008.

Source: Health Behavior News Service