Babies born by elective caesarean are almost 2½ times more likely to die within their first month than babies born vaginally, researchers have found, adding weight to the argument that caesareans should only be carried out in emergencies. The study, which involved more than 8 million births in the US over four years, is the first of its kind to focus on full-term babies born to women with no medical reason for choosing a caesarean over a vaginal delivery, an increasingly common phenomenon in Australia. One in three babies is now born by caesarean section, up from about one in five 10 years ago, but those born before the onset of labour are often unresponsive and unable to breathe without help.