Currently PG with DC1 and am intending to use (and quite excited about ) cloth nappies. However, a few people have advised me to get some disposables in to get us through the first couple of days of meconium and having no idea what we're doing, but I have no idea how many to get or what size.
Our choices are Mini (3-6 kg) or Midi (4-9 kg) and they come in packs of 48 or 144. 48 would last us what, four days - is that enough to get our heads around things and get to proper poo? Is 144 too many if I get Mini?
I'd buy a small pack of newborn nappies to take to hosp and then see what size your baby is. I bought far too many teeny disposables when they were on a special offer whilst pg with ds2. then he was a big baby who grew fast and I was left with all these nappies - so switched to my washables quicker than expected. Your DH can buy the appropriate size while you are in hosp. No reason why you can't use washables as soon as you come out of hosp though.
Go for 48 in mini, that should see you through the worst of the meconium phase.
You might subsequently want another 48 in midi - I've had 3 dc in cloth & still use disposables for days out/weekends away. Midi should fit for ages, so they are unlikely to go to waste (& will fit your newborn after you run out of 'mini', unless you have a very tiny baby).
I think you will find that you use them all so they won't be wasted. I found that I didn't put DD into cloth until about 6 weeks old, because she was too small (she was 6lb 1oz and my nappies, MEOS, didn't fit properly until she was about 8lb), but even once she was in cloth all day I left her in disposables at night until she slept through (she ALWAYS pooed during feeds so I always had to change her) and somehow at 3am or whenever it was I just found I coped better with a disposable! I always keep a couple of disposables around in case of emergencies or days out too.