Despite the startling technical advances that the field of medicine has made in the last few decades, women are taking longer to give birth now than they did 50 years ago.
A large study conducted in 2012 by the National Institutes of Health found that modern-day women spend an average of more than two and a half hours longer in the first stage of labor, the stage where the cervix gradually opens widely enough to allow the infant to pass through the birth canal.
Study authors analyzed figures from almost 40 thousand deliveries that took place between 1959 and 1966, and compared them to records from nearly 100 thousand deliveries that occurred between 2002 and 2008.
Researchers found that the first stage of labor had increased by 2.6 hours for first-time modern moms. And for women who had previously given birth, this early stage of labor lasted two hours longer in modern times than it did in the 1960s. The time differences remained, even after researchers took into account varying factors between the two groups, including weight, age, and race.
Additionally, infants born to modern-day moms were born an average of five days earlier than those born in the early 1960s. Modern babies also tended to weigh more.
Other differences between the two groups: modern moms weighed more than those who delivered in the 1960s. Present-day moms were also an average of four years older than moms who gave birth in the 1960s.
According to the study’s authors, the older age in modern moms may partly explain the longer delivery times, as older moms tend to take longer to give birth than younger moms. However, researchers stated that the age difference does not fully explain the longer labors.
Another factor that may contribute: changes in delivery practices, including the injection of epidural anesthesia into a mother’s spinal fluid, to lessen labor pain (epidurals can prolong labor by about 40 to 90 minutes). In the modern group, epidurals were used in more than half of the deliveries, compared to four percent in the 1960s group. The researchers noted that while epidurals can increase delivery time, they still do not account for all of the increase.
Ironically, doctors in the 2000s deliveries gave the mothers the hormone oxytocin in 31 percent of the cases, compared to 12 percent in the 1960s deliveries. Oxytocin is given to increase labor when contractions slow down. Technically, this should be making delivery times shorter, but that is not the case. Without oxytocin, modern deliveries might have taken even longer, study authors noted.
Other changes in modern-day delivery methods could also account for increased labor times. For instance, episiotomies and forceps were more commonly used in the 1960s than they are now. (An episiotomy is a surgical incision made to the opening of the vagina, to give baby more room to come out; forceps are surgical instruments used to pull the baby out of the birth canal.)
The study was published in the American Journal of Obstetrics and Gynecology.
By Jamell Andrews