Drospirenone-only Pill as Emergency Contraception

Serum progesterone concentration,Dominant ovarian follicle ultrasound measurement

Emergency contraception (EC) provides an additional measure to help prevent pregnancy after
 unprotected intercourse or contraceptive failure. The two currently available oral emergency
 contraceptive methods, levonorgestrel (LNG) and ulipristal acetate (UPA), have differing
 availability and effectiveness. Overweight and obesity are strong risk factors for failure of
 EC containing LNG and UPA for body mass index (BMI) ≥ 26kg/m2 and ≥35kg/m2, respectively,
 resulting in limited EC options for much of the population. Drospirenone is a unique
 progestin that effectively inhibits ovulation when taken daily as progestin-only oral
 contraception and has pharmacokinetic properties that make it a good candidate for a novel
 effective emergency contraceptive method across BMI categories.
 
 The investigators propose a dose-finding, adaptive-design pilot study evaluating if a single
 dose of drospirenone can inhibit ovulation prior to the luteinizing hormone (LH) surge. The
 dose-finding study design will be conducted in a well-established 3+3 model with 2 planned
 study arms stratified by BMI. The investigators hypothesize that a single dose of
 drospirenone will effectively inhibit ovulation when administered prior to the LH surge. This
 pilot data will directly support the dose selection for future research further evaluating
 the efficacy of drospirenone-only EC aimed at ultimately increasing oral EC options,
 particularly for patients with overweight or obesity.