Once the amniotic sac has been breached, the rest of the fetuses are left high and dry . ( So to speak . ) I'm guessing, but the sequence might be : woman goes into premature labour, rushed to hospital, one baby is already in the birth canal, it comes out and is handed over to neonatologist, contraction-inhibiting drugs are immediately administered to the woman, bed rest in hospital, lots of monitoring, try to give the other bun ( s ) as much more time in the oven as possible.