The medication abortion process, often referred to as “the abortion pill,” involves a two-step regimen using two different medications. The first drug, mifepristone, is taken orally and blocks the hormone progesterone, which is necessary to maintain the pregnancy. Without progesterone, the pregnancy cannot continue, and the uterine lining begins to break down. The second medication, misoprostol, is typically taken 24 to 48 hours later. Misoprostol is a prostaglandin that causes the uterus to contract and the cervix to soften. These contractions lead to cramping and heavy bleeding, which expels the pregnancy tissue, completing the process.
Defining Success and the Likelihood of Failure
A medication abortion is highly effective, but it carries a small possibility of failure. The combination of mifepristone and misoprostol successfully ends the pregnancy for approximately 94% to 98% of individuals. Failure requires further medical intervention and falls into two main categories. The first is an ongoing viable pregnancy, where the embryo or fetus continues to develop despite the medications. The second, more common type of failure is an incomplete abortion, where the pregnancy has ended but not all tissue has been expelled from the uterus.
An incomplete abortion may lead to prolonged bleeding or infection and requires medical management to remove the retained tissue. The risk of an ongoing pregnancy is low, estimated to be between 1% and 2% when the treatment is used under nine weeks of gestation. The small chance of failure necessitates a follow-up appointment to confirm the complete termination of the pregnancy.
Factors That Influence Effectiveness
The primary variable affecting the success rate of the medication regimen is the gestational age of the pregnancy. Success rates are highest in the earliest weeks, often exceeding 98% for those eight weeks or less. As the pregnancy advances, the effectiveness gradually decreases. For example, at nine to ten weeks of gestation, the success rate typically drops to the range of 91% to 93%.
Beyond ten weeks, effectiveness continues to decline, and the chance of needing a secondary procedure increases. Another element is strict adherence to the prescribed dosage and timing of the medications. Failing to take the misoprostol dose within the recommended 24 to 48-hour window after mifepristone can lower the overall efficacy. Furthermore, the route of misoprostol administration, such as buccal or vaginal, can also influence the outcome.
Recognizing Signs That the Treatment Did Not Work
Recognizing signs that the medication abortion may not have fully worked is important. The first sign of failure is a complete lack of the expected heavy bleeding and strong cramping following the misoprostol dose. Misoprostol is designed to cause uterine contractions that lead to bleeding heavier than a regular menstrual period, often with the passing of clots. If the bleeding is significantly lighter than expected, or if there is no bleeding at all, the process may have failed to initiate.
In cases of an incomplete abortion, the individual may experience prolonged or excessive bleeding. This is defined as soaking more than two sanitary pads per hour for two consecutive hours. Other warning signs include severe abdominal or pelvic pain that does not resolve with pain medication or a persistent fever. Additionally, the continued presence of pregnancy symptoms, such as severe nausea or breast tenderness, weeks after taking the pills could indicate an ongoing viable pregnancy. The only way to confirm success is through a follow-up test, such as an ultrasound or blood work, arranged with a healthcare provider.
Medical Options When the Pill Fails
When a medication abortion fails, further medical steps are necessary, whether due to an ongoing pregnancy or an incomplete expulsion. For an incomplete abortion, a healthcare provider might first administer an additional dose of misoprostol to complete the expulsion of the remaining tissue. If this is unsuccessful, or if the failure is an ongoing viable pregnancy, the standard treatment is a surgical completion procedure. This is typically a gentle suction aspiration that quickly and definitively empties the uterus.
The surgical option is the most reliable method for resolving a failed medication abortion. If a pregnancy continues after exposure to mifepristone and misoprostol, there is a slightly increased risk of birth defects. Medical professionals advise against continuing the pregnancy, making surgical completion the safest course of action in confirmed cases of ongoing pregnancy. The follow-up appointment is a necessary part of the process to ensure the complete and safe resolution of the pregnancy.