Drospirenone Only Pills and Cervical Mucus Changes: A Pre- and Post-Bariatric Surgery Study

Inclusion Criteria: * Thai women aged 18-45 years who are obese and had an appointment for Bariatric surgery at Chulalongkorn Hospital * Need contraception * Able to use non-hormonal contraception during the study * Giving consent Exclusion Criteria: * Pregnancy or history of giving birth within 3 months * Breastfeeding within the 6 months * History of using DMPA within 12 months * History of using other types of hormonal birth control pills within 4 weeks * History of bilateral oophorectomy or hysterectomy * Suspected ovarian tumor or pathological ovarian cyst * Regular cigarette smoking * Contraindications to Drospirenone