Authors pointed out that while the procedure is generally over-used in many middle- and high-income settings, women in low-income situations often lack necessarily access to what can be a life-saving procedure.
Over the past 15 years, this surgical intervention has nearly doubled surging from 12% to 21%, between 2000 and 2015, even exceeding 40% in some countries, as revealed in the recent study's report, issued today in the Lancet journal.
More and more women in the world have children, not naturally, but resorting to surgery.
The worldwide study, which involved several United Kingdom universities, is being presented at the global Federation of Gynaecology and Obstetrics (FIGO) World Congress in Brazil, where the authors are calling on healthcare professionals, hospitals, women and their families to only intervene with a C-section when it is medically required. The South Asia region has seen the most rapid increase in use (6.1 per cent per year), with C-section being underused in 2000 but overused by 2015 (increasing from 7.2 per cent of births to 18.1 per cent).
While C-section is a life-saving intervention for women and newborns, it is not without risk for mother and child, and is also associated with complications in future births.
In 15 countries, including the Dominican Republic, Brazil, Egypt, Turkey, Venezuela, Chile, Colombia and Iran, more than 40% of births occur by caesarean section.
"The sharp increase in cesarean sections, mostly in affluent environments without medical reasons, is problematic because of the risks for mother and child associated with C-sections", says Marleen Temmermann from the Aga Khan University of Kenya and Ghent University, in Belgium.
There is an urgent need for intervention in the medical field to reduce the use of cesarean sections, the researchers said.
In other words, the surgery should be used sparingly.
It is estimated that the operation - a vital surgical procedure when complications occur during birth - is necessary 10-15 per cent of the time.
Anything beyond that does not appear to reduce maternal and newborn mortality rates.
Improvements have been slow across sub-Saharan Africa (around 2 per cent per year), where C-section use has remained low, increasing from 3 per cent to 4.1 per cent of births in West and Central Africa, and from 4.6 per cent to 6.2 per cent in Eastern and Southern Africa.
"In some cases the trend is system-driven".
However, the Series authors estimate that more than one in four countries in 2015 had lower levels (28 per cent), while most countries used C-section above the recommended level (63 per cent).
Earlier this week, the World Health Organization published guidance highlighting the need to reduce unnecessary procedures that "cannot be medically justified".
The researchers also warned that in many settings young physicians are becoming experts in C-section, while losing confidence in their abilities to assist in vaginal birth. "Joint actions with governmental bodies, the health care insurance industry, and women's groups are urgently needed to stop unnecessary C-sections and enable women and families to be confident of receiving the most appropriate obstetric care for their individual circumstances".
The World Congress of Gynecology and Obstetrics (FIGO) advocates several measures to limit the abuse of caesareans: to apply a single rate for births, by caesarean section or not, to force hospitals to publish their statistics, to better inform women of the risks and improve training in natural birth.