Forget the bean bags, the muted lighting and the CDs playing in the background: when you're having twins, birth is a high-tech experience. "It was very different from my previous delivery when I was having just one baby," says Mary Walton. "Then, there was just me, my husband and - from time to time - the midwife. With the twins I was induced at 37 weeks and the room was full of doctors, paediatricians and nurses. I had an epidural, I was strapped to a monitor the whole time, I couldn't move around, and I had to give birth lying on my back on the bed."
She was, though, able to deliver her babies - Matilda and Edward - vaginally. But now a new study, published in the current issue of the British Medical Journal, is threatening to consign normal twin deliveries to history. Doctors who have studied twin births in Scotland over a five-year stretch say there is evidence that the second twin is more likely to die if born naturally rather than surgically. They admit their study size, at 4,500 twin births, is small, but nevertheless suggest that all women having twins at term (which, with twins, means 36-plus weeks) should be offered a caesarean.
At least one obstetrician, Professor Nick Fisk of Queen Charlotte's Hospital in London believes this study "may well be enough to tip the balance for most obstetricians towards recommending and offering caesarean sections to women pregnant with twins". It's a similar story to that of mothers carrying breech babies since the publication, in October 2000, of a much larger study which concluded that bottom-first babies were less likely to die if they were delivered surgically, rather than vaginally.
While everyone agrees that safety is paramount, this latest research is ringing alarm bells among many midwives and childbirth campaigners. No one wants to suggest a vaginal delivery if there is a clear risk to the baby: but is this, some ask, a clear risk? "I don't want babies to die, but I do think we should look at this very carefully before we make changes which are very difficult to undo," says Louise Silverton, deputy general secretary of the Royal College of Midwives.
"I fear that some obstetricians will leap in here and change their policy on twins as a result of it. But that's just taking the risk from the baby and transferring it to the woman, because a caesarean is major surgery for her and it does carry some risks. And no one is asking about what it's going to mean to a woman who's already gone through a twin pregnancy to then have major surgery - what about the effect on her future fertility? What about her chances of breastfeeding, which we already know is harder to do if you've had a caesarean section? We also know it's particularly good for twins, who are often smaller than singleton babies, to be breastfed."
Silverton is urging obstetricians to carry out further studies before changing their practice on twin delivery. With the caesarean rate currently at 21% and climbing, she argues, any wholesale change in policy will push the figures still higher at a time when most childbirth professionals, obstetricians included, believe they should be reduced.
How strong, though, is the obstetricians' commitment to reducing the figures? Could this study be part of what is widely seen among midwives as a slippery slope towards a situation in which caesarean section becomes the "norm" for childbirth - even, in the dim and distant future, the "safest" option?
"It's a terrible idea, but you can see where it's coming from," agrees Silverton. "After all, lots of interventions were originally introduced for high-risk women, and then transferred to all women - foetal monitoring, for example. It's not beyond the realms of possibility that someone will one day say caesareans are safer and preferable [than natural births] - and by that time, of course, most midwives and obstetricians will never have seen a completely normal birth to know what it looked like anyway."
Mary Newburn of the National Childbirth Trust says retrospective studies like this "are the weakest form of evidence and there definitely shouldn't be a knee-jerk reaction. We know that many women having twins can have a straightforward and happy outcome with a vaginal delivery. New motherhood in any circumstances can be difficult. But if you've got two babies and you're dealing with the aftermath of major surgery, it's really a very tough start indeed."
Professor Lesley Page, head of midwifery at London's Royal Free, says she would urge every obstetrician to read the study very carefully before using it to change existing practice. "We've always known that the second twin was at more risk and that we've got to pay particular attention to it, but this study doesn't give us any conclusions to draw on. I'd advise anyone expecting twins to find a consultant with a lot of experience in delivering twins naturally as well as surgically.
"Of course some women expecting twins will need to have a caesarean section, but there's nothing here to suggest that all women would, and I think it would be very misguided to move to a state of affairs where all mothers of twins were recommended surgical deliveries."