Drospirenone and ethinyl estradiol is a commonly prescribed combination oral contraceptive. It contains two synthetic hormones: drospirenone (a progestin) and ethinyl estradiol (an estrogen). This combination works to regulate the reproductive cycle and prevent pregnancy.
How Drospirenone and Ethinyl Estradiol Work
Drospirenone and ethinyl estradiol prevent pregnancy through a multi-pronged approach. The synthetic progestin (drospirenone) and estrogen (ethinyl estradiol) suppress the release of hormones from the brain, specifically follicle-stimulating hormone (FSH) and luteinizing hormone (LH). This suppression prevents the ovaries from releasing an egg, which is the primary mechanism.
Beyond inhibiting ovulation, these hormones also induce changes in the reproductive system that further reduce the likelihood of pregnancy. Drospirenone and ethinyl estradiol cause the cervical mucus to thicken, making it more difficult for sperm to travel through the cervix and reach an egg. The medication also thins the lining of the uterus, known as the endometrium, which makes it less receptive for a fertilized egg to implant. These combined effects create an unfavorable environment for conception.
Understanding Pregnancy Rates
The effectiveness of drospirenone and ethinyl estradiol is discussed in terms of “perfect use” and “typical use” pregnancy rates. Perfect use refers to effectiveness when the pill is taken exactly as prescribed. Under these conditions, combination oral contraceptives are highly effective, with a pregnancy rate of less than 1% per year, often cited as around 0.3%.
Typical use, however, accounts for real-world scenarios where adherence to the regimen may not always be perfect. This includes factors like occasional missed pills or inconsistent timing of doses. When considering typical use, the pregnancy rate for combination oral contraceptives rises to approximately 9% per year. This difference highlights the impact of human behavior and practical challenges on the overall effectiveness of the medication.
Factors Affecting Effectiveness
Several factors can reduce the effectiveness of drospirenone and ethinyl estradiol, increasing the risk of unintended pregnancy. Consistently taking pills at the same time each day is important, as missed or delayed doses can significantly lower the medication’s effectiveness.
Gastrointestinal issues like vomiting or severe diarrhea can prevent the proper absorption of the hormones, rendering the pill less effective. If these symptoms occur, it is often advised to use a backup contraceptive method. Certain medications can also interfere with the effectiveness of drospirenone and ethinyl estradiol, including some antibiotics like rifampin, specific anticonvulsants, and the herbal supplement St. John’s Wort. Individuals should always inform their healthcare provider about all medications, vitamins, and herbal products they are taking to identify potential interactions.
What to Expect After Stopping Use
When an individual discontinues drospirenone and ethinyl estradiol, fertility returns relatively quickly. For most people, ovulation can resume within a few weeks after stopping the pill. This means pregnancy can become possible shortly after cessation of the medication.
Many individuals may experience their first natural menstrual period about a month after stopping. Research suggests that many people conceive within the first few months of discontinuing the pill, with between 72% and 94% becoming pregnant within 12 months. Regular menstrual cycles are also re-established within a few cycles after stopping the medication.