Can I take citalopram while on birth control pills?

Patient: I am considering taking citalopram (generic celexa) but I also take birth control pills, specifically Zenchent 0.4 35(norethindrone and ethinyl estradiol tablets) Will the citalopram in any way affect the effectiveness of the birth control? Any risk, however small, I need to know about so I can make a decision about taking the citalopram. Thank you.