A US study has found that women are spending longer in labour than they did 50 years ago.
Scientists at the National Institute of Child Health and Human Development compared 39,491 births from 1959 to 1966 with 98,359 births from 2002 to 2008. All the women had gone into labour without complications.
The researchers found that the first stage of labour has increased by 2.6 hours for first-time mums, and by 2 hours for women who have already had children.
Babies of modern parents were born five days earlier, on average, than those in the 1960s, but also tended to weigh more.
So what caused the difference? The authors noted that on average, women in the modern group were 2.5 years older than those in the first. And women giving birth in the 2002-08 group had an average body mass index of 29.9, putting them close to the obese range, compared with 26.3 in the earlier group.
The first stage of labour has increased by 2.6 hours for first-time mums, and by 2 hours for women who have already had children
"Older mothers tend to take longer to give birth than do younger mothers," said the study's lead author, Dr S. Katherine Laughon. "But when we take maternal age into account, it doesn't completely explain the difference in labour times."
The researchers pointed to delivery room practices as a likely reason for the longer labours. Only 4 per cent of women in the earlier group received epidural analgesia, compared with 55 per cent in the recent group.
About 12 per cent of women in the '60s received oxytocin to induce labour, compared with 31 per cent in the modern group.
A team from the University of Sydney found that in Australia, epidural analgesia use increased from 17.2 per cent in 1992 to 26.5 per cent in 2003. In 1979, 75 per cent of births were to women under the age of 30; by 1999, births to women younger than 30 had dropped to 52 per cent. By 2009 this figure had dropped to 46 per cent, according to figures from the Australian Bureau of Statistics.
The New York Times