My information from my speciailst obstetrician before Connor was born is that the latest research has pretty much debunked the old wives tale of expressing inducing labour.....the most she said it might do is bring labour forward a few hours if you were already primed ready to go into labour. I pre expressed from 33 weeks with connor and was advised to freeze it every two days....so combine the two days worth and freeze as one lot........that worked welll for us....i just froze it in little specimen jars i got from the hospy. But definitely get your obs approval before pre expressing as every case is different.......