Many tasks can be tackled more quickly now than 50 years ago, but delivering a baby naturally is not one of them, a study has shown.
Compared with the 1960s, US women have in recent years spent two to three hours longer in labour, say researchers at the US National Institutes of Health, who said the findings suggested doctors might need to rethink the definition of “normal” labour.
The extra time is spent in the first stage of labour – the longest part, before the “pushing” stage of the process, according to findings published in the American Journal of Obstetrics & Gynaecology.
Mothers are different as well; on average, they’re older and heavier, and their newborns are bigger too.
“Even when we consider these changing demographics, labour is still longer,” said Katherine Laughon, lead researcher at the National Institute of Child Health and Human Development.
She said one partial explanation may be epidural pain relief, which was far more common now and slowed labour down.
The findings were based on two US government studies done decades apart.
One, between 1959 and 1966, included about 39,500 women who delivered a full-term baby, while the other tracked more than 98,000 women who had a full-term baby between 2002 and 2008.
All of the women had a spontaneous labour - that is, not induced.
When it came to length of labour, first-time mothers in recent years typically spent 2.6 hours longer in the first stage, compared with their counterparts in the 1960s. The difference dropped to two hours with women who had given birth before.
Contemporary women were far more likely to have an epidural - 55 percent, compared to just four percent of counterparts 50 years ago. Twelve percent had a C-section compared with three percent in the 1960s, while 31 percent were given oxytocin, which stimulates contractions, against 12 percent 50 years ago.
Laughon noted that many more women now have labour inductions or planned caesarean sections versus decades ago, so women who actually go into spontaneous labour these days may differ somehow from their counterparts of 50 years ago.
But, Whatever the underlying reasons, doctors may need to redefine “normal” labour, a concept that's based on what was the norm for women a half-century ago.
For example, labour is considered to be abnormal if there’s no change in the cervix after two hours in the “active” part of the first stage. At that point, doctors may intervene by doing a Caesarean.
“We need to revisit the definitions of ‘abnormal’ labour, and the timing of the interventions we use,” said Laughon. – Reuters