1. How do octuplets happen?
Not easily. Human females are designed to release one egg per month - even a release of two eggs, which could lead to twins, is unusual (that, after all, is why women have just the two nipples - in species where multiple births are common, the females are better endowed with feeding equipment). For a woman to conceive eight babies naturally, she would need to release maybe four or five eggs (extremely unlikely), and all or most of the eggs, once fertilised, would have to go on to split to form twins or triplets (again, this would be mind-bogglingly rare).
What's more likely is for octuplets to be conceived as a result of fertility treatment, if a number of fertilised eggs were returned to the womb and these went on to split into two or three babies. (This couldn't happen in the UK, because a maximum of two fertilised eggs only can be returned to the womb - but that rule doesn't apply in the US.) Yet another possibility would be if a woman who was taking fertility drugs to stimulate egg production had unprotected sex - which is how Mandy Allwood, who got pregnant with octuplets in 1996 but then miscarried, conceived hers.
As far as the unidentified new mother from Los Angeles who gave birth to octuplets this week is concerned, we are none the wiser - the hospital where she gave birth, Bellflower medical centre, is refusing to say whether fertility treatments were involved in this conception or not.
2. What are the risks - and how likely are the babies to survive?
An octuplet pregnancy isn't eight times as dangerous as a singleton pregnancy, says Professor James Walker, obstetrician at St James's Hospital in Leeds and a spokesman for the Royal College of Obstetricians and Gynaecologists - but there are greatly increased dangers of gestational diabetes and hypertension. "Another big risk is of a postnatal haemorrhage in the hours after delivery - eight babies means eight placentas, which means eight different sites in the uterus that can become a site for major bleeding."
Mothers found to be carrying so many babies are usually offered the chance of a partial abortion, to reduce the number of foetuses and so increase the chances of getting to term (Allwood famously refused this option). Now they're safely born, the main issues for the LA babies will be respiratory and feeding problems. The babies in this case are comparatively good weights - between 1lb 8oz (820g) and 3lb 4oz (1.47g) - but the next few days will be critical.
3. What has happened to other octuplets?
Other octuplets have been born before - but in no recorded case has every baby survived. A set was born in Texas in 1998 to Nkem Chukwu, but the smallest, named Odera, died after a week. The surviving seven - five girls and two boys - celebrated their 10th birthdays last December. They live with their parents and six-year-old-sister in a six-bedroom house in the Houston suburbs that was donated to the family, and travel in a 16-passenger van. Their grandmother set up assembly lines to feed them when they were small; their mother has described raising them as "more than a full-time job".
A woman in Turkey lost all eight of her octuplets in 1985, as did Allwood in the UK in 1996, when hers were born at 22 weeks; two of a set born in Italy in 2000 died, and all of a set born in Mexico City in 1967 died within 14 hours.
The largest multiple birth ever recorded was nonuplets in Australia in 1971 - all nine died within a week.
4. Can the mother breastfeed them all?
Almost certainly not. However much we may admire the LA mother's desire to feed all these babies herself, the logistics are against her. New mothers often spend six hours or more in 24 feeding even a single baby. Assuming the Californian mother manages to feed two babies at a time (not as easy as it sounds), she could easily be feeding round-the-clock.
But Anna Burbidge of the breastfeeding-championing organisation La Leche League says it's possible that the new mother will be able to express enough milk in the next few days to ensure each of her eight tiny infants gets a small amount - and, given that the breastmilk of a mother who has had premature babies is packed with precisely the nutrition they need, that could be the most important breastmilk they ever get. "At that stage, the babies only need minute amounts of milk to fill their tiny tummies," she says. "They'll probably be being tube-fed at this stage."
Beyond that, she's loth to say it will be out of the question for the Californian mother. "After last year's earthquake in China there were reports of a 29-year-old policewoman, who had not long ago given birth herself, breastfeeding eight babies who had been orphaned," says Burbidge. "It sounds impossible, but maybe it's not. Feeding them any way is going to be difficult ... perhaps she'll be able to have a rota so they alternate breastfeeds with bottle feeds."
However, a word of warning from Janet Walton from Merseyside, who gave birth to the world's first all-female sextuplets in 1983: "It was a madhouse, with feeding and changing nappies throughout the day and night. It was like painting the Forth bridge, we never really stopped."
5. How much will it cost to raise them?
The US department of agriculture reckons it costs around $200,000 (£140,000) to raise one child to the age of 17 (and that's not taking into account the amount the LA family will have to spend on extra help and expensive baby equipment). So even a conservative estimate would put the cost of eight, to adulthood, at around a staggering $1.6m.
Parents with multiples are often approached by companies offering sponsorship but, says Sarah Newell of the Twin and Multiple Birth Association, these aren't without their drawbacks. "What we hear from families who've been in this situation is that nothing comes for free - you have to work for these deals, and what sponsors usually want is press appearances and photoshoots. It's not always conducive to family life."
6. Can they all go for a walk together?
Astonishingly, yes. What they need, says Newell, is a quad-buggy, which comes in an impressive four-square formation: in the UK, these retail at around £600. "They're not cheap, but they do make it doable for one parent to push four babies, and the other parent to push the other four," she says. An alternative would be to buy two triple-buggies and for each parent to carry a baby in a sling - but that wouldn't be practical in the longterm, so the quad buggies are the best option.
7. How many nappies will they get through?
A newborn baby needs an average of eight nappies in a 24-hour period: so we can expect the octuplets to use around 64 in a day, 448 in a week, and 23,296 a year. Given that they are likely to be in nappies for the first two to two-and-a-half years, that's going to be an awful lot of nappies - the bill for the octuplets will be around $16,000. And as for the green option - let's not go there. This new mother has quite enough on her plate without taking on more washing.
8. And, finally, what about the sibling rivalry?
"It's very common with multiples," says Newell. "The problem is that you can't give as much attention to several babies as you can to one, and it's that lack of parental attention that can go on to cause problems later on. Even raising my twins, I felt guilty that I couldn't give them enough time - you think, how long is it since I gave that one a cuddle?"
So what's it going to be like for the parents of eight? "Very, very difficult. But the most important thing will be seeing them as individuals. We'd strongly advise against dressing them identically - they do look cute, but it causes lots of problems. If you want your children to think of themselves as individuals, which is the best way to reduce the risk of sibling rivalry, then don't dress them all the same."
Walton says of her sextuplets: "Amazingly, they are all close. They have their moments when there are arguments and with eight adults living in the house there is bound to be a bit of friction but we have great fun and a lot of laughs. Overall, it was hardest physically when they were toddlers and all over the place".
• Additional reporting by Helen Carter
