Washington, Apr 1 (IANS): Women take longer to deliver babies today than they did 50 years ago, according to an analysis of nearly 140,000 deliveries, conducted by researchers at the National Institutes of Health (NIH).
Researchers compared data on deliveries in the early 1960s to data gathered in the early 2000s. They found that the first stage of labour had increased by 2.6 hours for first-time mothers.
For women who had previously given birth, this early stage of labour took two hours longer in recent years than for women in the 1960s. The first stage of labour is the stage during which the cervix dilates, before active pushing begins, the American Journal of Obstetrics and Gynaecology reports.
Infants born in the contemporary group also were born five days earlier, on average, than were those born in the 1960s, and tended to weigh more, according to an NIH statement.
The women in the contemporary group tended to weigh more than did those who delivered in the 1960s. For the contemporary group, the average body mass index before pregnancy was 24.9, compared with 23 for the earlier generation.
Body mass index is a measure of body fat based on height and weight. At the time they gave birth, the mothers in the contemporary group were about four years older, on average, than those in the group who gave birth in the 1960s.
"Older mothers tend to take longer to give birth than do younger mothers," said the study's lead author, S. Katherine Laughon, epidemiologist at the Eunice Kennedy Shriver National Institute of Child Health and Human Development, Rockville, Madison.
"But when we take maternal age into account, it doesn't completely explain the difference in labour times," added Laughon.
Among the change in delivery practice the researchers found was an increase in the use of epidural anesthesia, the injection of pain killers into the spinal fluid, to decrease the pain of labour.
For the contemporary group, epidural injections were used in more than half of recent deliveries, compared with four percent of deliveries in the 1960s.