Health News: NIH Study Finds Women Spend More Time in Labor Than 50 Years Ago

Women take longer to give birth today than women 50 years ago, according to an analysis of nearly 140,000 deliveries conducted by researches at the National Institutes of Health. The researchers could not identify all the factors accounted for in the increase, but concluded that the change is likely due to changes in delivery room practice.

The researchers compared data on deliveries in the early 1960s to data gathered in the early 2000s. They found that the first stage of labor had increased by 2.6 hours for first-time mothers. For women who had previously given birth, this early stage of labor took two hours longer than it did for women in the 1960s. The first stage of labor is the stage during which the cervix dilates.

Infants born in the contemporary group were born five days earlier on average, yet tended to weigh more. The women in the contemporary group tended to weigh more (with a BMI of 24.9) than did those who delivered in the 1960s (with a BMI of 23).

“Older mothers tend to take longer to give birth than younger mothers,” said S. Katherine Laughon, MD, the study’s lead author. More older women give birth today than women in the 1960s.

The changes in delivery practice include an increase in epidural anesthesia, which were used in more than half of recent deliveries, compared to four percent in the 1960s. The study authors believe that epidural anesthesia increases delivery time, but doesn’t account for all of the increase.

Doctors in the early 2000s also administered the hormone oxytocin more frequently (in 31 percent of deliveries, compared with 12 percent in the 1960s), the researchers found. Oxytocin is given to speed up labor, often when contractions seem to have slowed.