The service is presently run at enjoyleisure's sports centres in Musselburgh, Tranent, Haddingtion, North Berwick and Dunbar. It is expected to be withdrawn from these centres throughout 2019.
Mr Beattie remarked:
'There is no doubt this decision is highly disappointing.
'Constituents have been in touch with me to say how angered they are that this service will no longer be available, and I strongly agree with them.
'This past week the First Minister announced £50m of funding to help new mothers with their mental health. We know that exercise is highly beneficial for mental health, not to mention physical health, and yet new mothers in East Lothian are going to find it more difficult than ever to properly exercise.
'I note a campaign has been set up urging enjoyleisure to reconsider its decision and I implore the board to take note of this.
'We should be doing everything we can to promote exercise to new parents. Closing the creche services flies in the face of sound common sense and reason.'