Birth control in methadone?

I'm sorry if it offends anyone but I agree with this, the suggestion of Scottish M.P. Duncan McNeil, that birth control drugs be added to methadone.

I'm sure there will be those out there that start making noises about civil liberties and freedoms but what about the rights of the child.... and of the mother for that matter? The effects of methadone, or it's street equivalent, on a foetus, both long and short term are all too obvious but the mother herself is likely to encounter a difficult pregnancy when she is least able to cope and subsequently be unable to take proper care or responsibility for any child. I'm far from unsympathetic toward those fighting any addiction, quite the contrary but this is obviously not a permanent method of contraception, just a sensible one....albeit probably unpopular!