Taking birth control pills around the time of surgery may slightly increase the chance of blood clot formation.
The patient and doctor must decide whether the risk warrants going off the birth control pills, including the downside of bleeding for three months, face breaking out, mood changes, etc. etc. etc. that many women experience when they alter their birth control regimen.
While postmenopausal hormone supplements (including bioidentical in my opinion) would predispose to blood clot formation and we do strongly recommend patients discontinue them, we would consider birth control pills a softer factor.
We allow the patient to make that decision after giving the options to her. Like so many things in medicine, there are pros and cons to most issues.