Effect of sugammadex on the serum plasma levels of circulating oestrogens and progesterones in healthy females who take hormone contraception in the perioperative setting

Pre-menopausal women between 18-50 years old who are undergoing a planned operative procedure, are on a hormone contraceptive, and receiving 1 dose of IV sugammadex (dose variable based as determined by treating anaesthetist) will have 3 serum samples (time = 0min, 15min, 240min post-sugammadex) taken to assess the change in serum oestrogen and progesterone. Note: time for sugammadex = 0 minutes can be anytime prior to administration of sugammadex. Timing of sugammadex administration is at end of the procedure though timing will vary depending on each case and treating anaesthetist. The eligibility of participants will be based on a questionnaire if they are likely to receive sugammadex in their procedure. There are no changes to a patient's anaesthetic regimen as determined by their treating anaesthetist (i.e. they would receive sugammadex regardless if participants were enrolled in the study).