This topic is somewhat controversial; there is no “standard” or official recommendations that can be made here. Although it is thought that the use of estrogens (or the natural higher concentration of estrogen seen during later pregnancy) may lead to a greater incidence of thromboembolic events (clot formation and lower extremities and/or lungs), there is no "standard of practice”. Some of the studies I have looked at demonstrate a 9 time greater risk of admission to a hospital for treatment of thromboembolic events (1:2000) for women who use oral contraceptives, compared to women who do not use oral contraceptives (1:20,000). These studies do not involve surgical patients. Some studies Involving surgical patients report that for those women taking an estrogen containing oral contraceptive and undergoing elective major surgery there is a doubling of the risk of deep venous thrombosis, relative to the general population.
The risk seems to be somewhat dependent on the type of oral contraceptive, and the quantity of estrogen involved. Other risk factors include obesity, inherited blood clotting disorders, a previous history of deep venous thrombosis, cancer patients, certain auto immune diseases, inflammatory bowel disease, hypothyroidism, renal disease, long-distance air travel…
The stopping of oral contraceptives prior to surgery may be of concern to patients/physicians at the risk of pregnancy is high, due to improper technique or low success rate. There are papers published recommending the continued use of oral contraceptives for this reason. These authors recommend careful attention to the use of venus thromboembolic prophylaxis during the time around surgery. The alternative strategy is to switch women to progestin only pills, as this does not have a high association with thromboembolic events.
On the other hand, there are many authors, based on their studies, who recommend stopping the use of oral contraceptives prior to surgery. The recommendations for the length of time, prior to surgery, that these medications should be stopped vary; the optimal time for cessation is not known. The most common recommendations I have seen is to stop the use of estrogen related containing oral contraceptives 4 weeks prior to surgery.
Ultimately, you will need to check with your own plastic surgeon ( and possibly OB/GYN physician) for their recommendations. As I mentioned above, these recommendations will vary from one practice to another. In my practice, given that we know the risk of venous thromboembolic events are cumulative ( and we want to do everything we can to decrease risk), I recommend stopping oral contraceptive pills four weeks prior to major elective surgery and the use of an alternative method of birth control. Of course, the use of other measures such as early ambulation and the use of pneumatic compression stockings are routine.
I hope this helps.