Can you switch to edibles? The only thing that might be bad for the baby is smoke. With edibles, there is no smoke. I do know that smoking marijuana is detrimental to the lungs. I also do know for sure that tobacco smoke is VERY detrimental to babies and can lead to asthma and even SIDS. So may be marijuana smoke can, too? Find out. If you cannot switch to edibles, can you smoke outside?

Your wife should be trying to problem solve with you to protect the health of the baby. That is fair and constructive. If she is using the arrival of the baby to exert influence on you and control your behavior, that is unfair.

I hope you can sort it out. To get rid of your babys father over occasional pot use is ridiculous. Could it be that it is her excuse and she has other motivation to want to get rid of you?