Births by Caesarean section in the United States reached an all-time high in 2007 when some 1.4 million babies, or 32 percent of births, were delivered by C-section, a study showed Tuesday.
The rate of Caesarean sections jumped by 53 percent between 1996 and 2007, and the number of births by C-section soared by 71 percent during the same period, the study released by the National Center for Health Statistics shows.
In one year during the study period, 2006, Caesarean delivery was the most frequently performed surgical procedure in US hospitals.
The rate of Caesarean births -- a major surgical procedure in which the infant, placenta and membranes are extracted from the womb through an incision made in the mother's abdominal and uterine walls -- rose for women in all age groups and across all ethnic groups.
Women under the age of 25 saw the steepest rise, with C-sections rising by 57 percent, from 17 percent of births to 27 percent between 1996 and 2007.
But older women were still the most likely to have babies by Caesarean section: 48 percent of mothers aged 40-54 years delivered their babies by C-section in 2007, compared to 23 percent of mothers under 20.
The World Health Organization says the optimal Caesarean birth rate is 15 percent.
Older maternal age was one reason Caesarean births are on the rise, according to the study.
That was partly because women in their 30s and 40s who interrupt their careers to have a baby, want the birth to fit around their work schedule, said Dr Judith Rossiter, head of obstetrics and gynecology at St Joseph's Medical Center near Baltimore.
"They basically want to put their delivery date on their Blackberry," Rossiter told AFP.
"They say: 'I want to have my baby on March 24th at 8:00 am because I have a big meeting the day before and I have to be back at work six weeks later.'"
The study also cited "legal pressures" on US obstetricians as a reason for the rise in C-sections.
"There are many obstetricians who are running scared and doing more Caesarean sections, not because they are medically indicated but because they don't want to be sued for having not done a C-section," Rossiter said, adding that the statute of limitations for obstetricians in the United States is 21 years.
"Although studies have not shown Caesarean section births to be safer than vaginal births, what the attorneys say when you go to court is: what if you had done a C-section? Would this child or baby have this problem?" said Rossiter.
"If you have done a Caesarean section, you don't tend to wind up in court as often, not because the baby's normal but because the attorney can't use that line of argument," she said.