Smoking and IVF

Does anyone have a husband who smokes the ‘green stuff’ “occasionally” (approximately once a week) and continued to do so during <a href="">IVF</a> cycles? Currently having an argument as I believe he should abstain until we are successful... I figure every little bit matters. Doctor had originally told him no on the smoking. Also, he has low morphology but all other numbers normal. Testing on me didn’t find any issues but our doctor suspects maybe non functioning tubes or endometriosis