The use of caesarean sections to deliver babies has reached epidemic proportions, say experts, with the procedure growing in use at an “alarming” rate.

While caesarean sections can be a crucial intervention for the safety of the mother and child, for example if the baby is showing distress or if the mother is bleeding before birth, experts say the procedure would account for about 10-15% of births if only used when medically necessary.

But in a new series of studies and commentaries published in the Lancet, a team of researchers have revealed that in many countries caesarean sections are rising rapidly, accounting for more than 21% of births globally in 2015, up from just over 12% at the turn of the millennium.

In the UK the figure stands at just over 26%, but in some countries more than half of births involve the procedure: in the Dominican Republic over 58% of babies are delivered this way, while in Egypt the figure is 63% when looking just at births in institutional settings.

Experts say more needs to done to raise awareness among women, their families and medical professionals of the potential risks of caesarean sections when not needed for medical reasons.

“For the mother, for her future pregnancy there is an increased risk of preterm birth, ruptured uterus and the placenta embedding in the wrong part of the uterus, which means she is at risk of postpartum haemorrhage and needing a hysterectomy,” said Jane Sandall, professor of social science and women’s health at King’s College London and a co-author of one of the studies.

Some of the risks increase the more caesarean sections a woman has: according to one study referred to by the team, the need for a hysterectomy increased from one in 25,000 pregnancies in women who had not previously had a caesarean section to one in 20 for women who have had three or more.

The authors add there is also a risk of blood clots in the mother’s legs, problems from the anaesthetic, and infection among those opting for a caesarean section, while in the baby there is a greater risk of problems around the development of the immune system and autoimmune disorders. The procedure also affects the makeup of the baby’s gut microbiome, and increases their risk of obesity and asthma.

The authors note that the risks are generally small and depend on where in the world the operation is taking place. They also admit there has been little research into the psychological effects of opting to have a caesarean section compared with vaginal delivery.

While Sandall said there is not one rate or target to aim for, she said it is important to listen to why women elect to have the procedure.

“For many women it is about fear of birth, or something has happened to her in her previous care where she was treated in a way that she wasn’t happy with and she is using [a caesarean] as a way of getting control back,” she said.

Sandall said time constraints and staffing problems mean women do not always receive the support they need, but that medics should provide information and offer possible ways to mitigate fears around vaginal birth.

“It is our job to provide as accurate information as we can … it is not our job to tell women what to do,” she added.

The new research suggests the global rise in caesarean sections is down to more women giving birth in medical institutions such as hospitals, combined with increased use of the procedures there.

More specifically, the reports suggest factors that may play a role include women’s fear of labour pain, concerns about their future sex life and the idea that a caesarean is safer. For obstetricians, fear of being sued – which is more likely for vaginal deliveries – greater financial reward and even juggling work schedules might mean they are more likely to agree to a request for the procedure, or suggest it.

“In many settings, young obstetricians have become experts in [caesarean sections], but are losing confidence in undertaking vaginal-assisted deliveries and breech deliveries,” the experts warn.

While research is lacking on the best way to tackle overuse of caesarean sections, experts recommend improved support for women and audits of caesarean use, and stress the importance of midwives.

The team add that while globally the proportion of caesarean sections is excessive, use of the procedure varies from country to country, with greater use in wealthier regions. By contrast, 47 of the 169 countries studied by the researchers have levels of caesarean section use below what is considered medically necessary: in west and central Africa the figure is just over 4%, suggesting some women and babies are missing out on life-saving care.

Caesareans are also more common in some countries for wealthier women and in the private sector.

Mandy Forrester of the Royal College of Midwives said it was “crucial that women are aware of the potential complications of having a caesarean section in the short and long term. To ensure this happens we need to give midwives the time to sit and discuss a woman’s options for the birth of her baby. It is very important that women make their decisions based on the best available evidence.”

“In Brazil, there’s a belief that normal childbirth is something the poor do”

More than half of all births in Brazil are via caesarean section, according to the latest data from the Lancet. Although natural births are more common in public hospitals than in private clinics, about 55% of women in Brazil give birth via caesarean section.

“It’s quite worrying,” said Silvana Granada, one of the lead childbirth researchers at Brazil’s Oswaldo Cruz Foundation (Fiocruz). According to Granada, as many as 70% of women first say they want a natural birth. But this “reverses” as they reach the end of their pregnancies, with the majority voicing preference for caesarean sections.

Granada said a nationwide study by Fiocruz in 2012 found that women often made this choice out of fear of pain or because they believed caesarean births were safer. Until very recently, medical labour practices in Brazil have done little to change this belief.

Up until a decade ago episiotomies – surgical cuts made at the opening of the vagina during childbirth – were used for every single natural birth. The procedure is much less common now.

Other practices known to increase pain are still common among births, however, such as use of the drug oxytocin, which can speed up labour but is also known to increase discomfort. The study also found that doctors still often bind women to their beds and forbid them from walking around, or leave them without food or drink during labour.

Another factor is the divide between public and private maternity units, where practices may differ substantially. Women of a lower social class were more likely to give birth in a public unit, and health insurance plans used for private maternity hospitals often only cover caesarean births. Granada said women who want a natural birth in a private clinic “are charged an extra cost, or have to pay the whole cost of the birth”.

César Eduardo Fernandes, president of the Brazilian Federation of Gynecology and Obstetrics Associations, said social and cultural factors also influence women’s choices when it comes to vaginal birth versus caesarean sections.

“In Brazil, there’s a belief that normal childbirth is something the poor do,” he said. “Those who have the economic capacity choose caesareans.”

In private clinics, which often assign each patient a doctor to accompany their entire pregnancy, the convenience of a one-hour caesarean birth compared to a long natural labour could also influence practices. Granada said the majority of caesarean sections in Brazil are scheduled in advance rather than when a woman goes into labour, and are normally set to take place during working hours during the week.

Legal risks for obstetricians are also a factor, according to Fernandes. “Obstetricians are the most sued doctors in our country, after plastic surgeons,” he said.

Brazil is taking steps to tackle its high caesarean rate. In July 2016, the federal government passed a resolution that advised caesarean sections should only be planned for high-risk pregnancies, and only after the 39th week. Data has yet to be collected to show the effect of this on caesarean rates in Brazil, but researchers and practitioners believe they are decreasing.

Fiocruz’s most recent studies, the results of which were collected in 2016 and are still being analysed, show an improvement from past childbirth practices. Granada said the number of caesarean births has reduced.

“It’s getting better,” she said. “But we still have a lot to improve to have more adequate deliveries, where the woman is the protagonist rather than the healthcare professional.”