More than one in four babies born in Canada enter the world via caesarean section, a trend that increases risks in childbirth and burdens the health-care system, according to the Society of Obstetricians and Gynecologists of Canada.

In a news bulletin issued Wednesday, the society says that C-sections, in addition to increasing the risk of bleeding, scarring, infection and chronic pelvic pain, can also make subsequent pregnancies riskier and more prone to complications. Many women who have had one C-section also choose or require a second one, it says.

The society cites 2007 research by the Canadian Perinatal Surveillance System that finds elective C-sections also carry with them risks such as complications from anesthesia, obstetrical wounds and cardiac arrest.

It calls on medical professionals to perform the procedures only when medically necessary.

"While the individual risk for a woman having a C-section is very small, the rising rate is certainly a concern," society president Dr. Guylaine Lefebvre said in a release.

"We fear that there may be an emerging trend towards more scheduled childbirth and routine intervention. We need to be sure that C-sections are not driven by convenience, that interventions are medically indicated and that the safety of a woman and her baby are the driving factors in these decisions."

Andre Lalonde, the society's vice-president, said that C-sections are burdening the health-care system, which already has a shortage of obstetricians and other doctors.

Between 1993 and 2006, Canada's C-section rate grew to 26.3 per cent of all deliveries from 17.6 per cent. The increase is attributed an increase in the number of obese mothers, in which more pregnancy complications necessitating a C-section can arise, and older maternal ages.