Pregnant women are spending more time in labour now than 50 years ago, a recent study has discovered.
The research by the National Institutes of Health analysed nearly 140,000 births and compared data on deliveries in the early 1960s up until the early 2000s.
Nearly 40,000 deliveries were investigated between 1959 and 1966, and a further 100,000 births between 2002 and 2008.
They discovered that the early stages of labour (from when the cervix begins to dilate) lasts 2.6 hours longer for modern, first-time mothers compared to their counterparts in the 1960s.
Women who had previously given birth had gone through the early stages of labour two hours longer than those in the 1960s.
Researchers claim that the labour time has changed because of differences in delivery room practices.
For example, the use of epidural anesthesia (the injection of pain killer into the spinal fluid) has increased from 4% in the 1960s to more than 50% of recent births. Anesthesia is known to increase labour times.
The study also focused on how often the hormone oxytocin is given to women in labour. Oxytocin is administered to induce contractions or to speed them up when they slow down and is given to 31% of modern day women compared to 12% of pregnant women in the 1960s.
Although oxytocin is effectively designed to speed up the labour process, research suggests that it makes little, or no, difference to the length of time women spend in labour.
Another difference in birth practices that the study noted included the faded popularity of episiotomy (where a surgical incision is made to enlarge the vaginal opening to make way for the baby if labour slows down). This was usually followed by the use of forceps (a clamp-type instrument that swiftly extracts the baby from the birth canal).
However, during modern births, medical intervention is more complicated and usually includes oxytocin administration or a caesarean delivery, which involves surgically removing the baby from the womb.
Practices aside, researchers also highlighted that pregnant women weigh more than those in the 1960s. Modern pregnant women have a body mass index (BMI) of 24.9 compared to 23 for the earlier generation. Obesity during pregnancy increases the risk of complication during the birth.
Researchers concluded that modern delivery practices needed to be re-evaluated.
These findings were published in the American Journal of Obstetrics and Gynecology.