Giving birth takes hours longer today than it did 50 years ago in the USA, according to a report issued by the National Institutes of Health (NIH). The authors wrote that most likely, changes in delivery room practice, as well as some other factors have made labor longer today. They gathered data on almost 140,000 deliveries.

The authors stressed that additional studies are required to determine whether present delivery practices are impacting on longer childbirth periods, and by how much.

The scientists compared childbirth data in the early 1960s to information available from the beginning of this millennium. Over the last 50 years, first stage labor has increased in duration by 2.6 hours. For those who had already given birth, early stage labor took 2 hours longer 50 years later. First stage labor occurs before active pushing starts; when the cervix dilates.

Babies in the early 2000s were born, on average, five days earlier than their early 1960s counterparts – and also had higher birth weights. Mothers giving birth in the early 2000s weighed more than mothers fifty years earlier. In the early 1960s, the average BMI (body mass index) of a mother before pregnancy was 23, compared to 24.9 fifty years later. The early 2000 mothers were approximately four years older than those who had given birth fifty years earlier.

Lead author, S. Katherine Laughon, M.D., said:

“Older mothers tend to take longer to give birth than do younger mothers. But when we take maternal age into account, it doesn’t completely explain the difference in labor times.”

Only 4% of earlier mothers had painkilling injections into the spinal fluid (epidural anesthesia), compared to over 50% fifty years later. It is well known that epidural anesthesia increasing delivery time. However, the authors stressed this one difference in delivery practice does not account for all the increase in delivery times.

Oxytocin, a hormone, was delivered to 31% of early 2000 mothers during childbirth, compared to 12% five decades earlier. Oxytocin accelerates labor, and is used when contractions appear to have slowed. Oxytocin is thought to reduce childbirth times.

Dr. Laughon said:

“Without it (oxytocin), labor might even be longer in current obstetrics
than what we found.”

The following were more commonly used in the early 1960s compared to early 2000s:

  • Episiotomy – enlarging the vaginal opening with a surgical incision during childbirth

  • Forceps

  • Other surgical instruments to extract the baby from the birth canal

If labor fails to progress, doctors are more likely to intervene today. An example is if cervix dilation slows down, or when the active phase of labor stops for a prolonged period (doctors may perform a C-section or administer oxytocin).

The c-section rate today is four times higher than it was in the early 1960s.

Written by Christian Nordqvist