Ok I'll do it for you - Shortly after conception and for the next 18 years Boom-tish
I wrote recently about a new study which disproved the idea that inducing labour increases the liklihood of a women ending up with a Caesarean section. Hot on it's heels came another publication which called into question more of the perceived wisdom about childbirth. Namely the idea that it's best to wait until labour is well advanced before having an epidural.
The Science bit:
Like the previous study this was a large systematic review looking at lots of previous work so it's pretty reliable and avoids or at least accounts for the many issues that can plague individual studies. It included 15,752 first time mums and compared those who had an epidural "early" in labour, which was defined as less than 4-5cm dilated (the exact cut off varied a little between studies), and those who had epidruals "late" (ie. they were more than 4-5cm dilated).
The conclusions of the study are pretty clear. Having the epidural early or late in labour made no difference to the babies' Apgar scores or to the likelihood that a woman would go on to have a c-section or an instrumental delivery. It also had no effect on the length of the second (pushing) stage of labour. One area where the individual studies did vary a lot was on the overall length of labour, so the review wasn't able to make any firm conclusion about the effect of an early epidural on this. Interestingly though it seems it's not just unclear if an early epidural increases labour time, it's not impossible that it has the opposite effect. Lead researcher Dr Ban Leong Sng said:
"We can't rule out the possibility that starting epidural pain relief earlier may lead to shorter labour, ...This is because there was a lot of variation in the results of the studies we looked at in terms of the length of the first stage of labour."
Asking around there seems to be a great deal of variability in when a woman is "allowed" an epidural. Personally, my midwife agreed as soon as I asked for one, but I had already been in labour for 24 hours at this point and, frankly, I think she needed a rest too. However, other women are told they must wait until their labour is more progressed. For some this doesn't only mean that they are left in pain for longer than they want (which is bad enough when it's so avoidable). Some end up not getting the epidural at all. I had a long wait for one as all the anesthetists were busy, but I wasn't too concerned as I still had a long way to go and starting the gas and air took the edge of. But others have told me that, having been refused an epidural, their labours then progressed rapidly and and it became impossible to find an anesthetist, and get the epidural in and working before the baby arrived. For women who had decided they wanted pain relief this can be very traumatic.
There are of course plenty of pros and cons to having an epidural at all and this study makes no comment on that. In reality most women find childbirth to be extremely painful and many will want to take that pain away. An epidural is probably the most effective way to do this. In my opinion it is neither stupid to want to experience the pain of birth nor weak to want that pain removed. It is a personal choice for each woman and one that can't be finalised in advance. What this review tells us is that, if a women has decided she definitely wants an epidural, she shouldn't feel she needs to hold out for as long as possible and she certainly shouldn't be forced or coerced into waiting because of some idea that it will be better for the baby or the birth process.
So when is the best time for a woman in labour to have an epidural? -
Whenever she decides she wants one.
SBxPS. Here is a link to the full Cochrane review in case anyone needs to wave it in someone else's face!