An abortion is a medical procedure that ends a pregnancy by removing the embryo or fetus and the placenta from the uterus. Options are available very early, often as soon as a positive pregnancy test is confirmed. The choice between methods depends on the precise timing, which is measured from the first day of the last menstrual period, not the date of conception.
Calculating Gestational Age
The medical community uses a standardized measurement called gestational age to determine how far along a pregnancy is, a metric that dictates the available abortion options. Gestational age is calculated from the first day of the last menstrual period (LMP), which is typically about two weeks before conception occurs. Therefore, immediately after a missed period and a positive test, a pregnancy is already considered to be around four weeks of gestation.
While the LMP provides a quick estimate, an ultrasound examination is often used to confirm the gestational age, especially if menstrual cycles are irregular or the LMP is uncertain. During the first trimester, precise measurements of the embryo or gestational sac via ultrasound are the most accurate way to verify the number of weeks. This timing directly influences whether a medication or an in-clinic procedure is the most appropriate option.
The Earliest Option: Medication Abortion
Medication abortion, typically the earliest available option, is offered shortly after a positive pregnancy test, generally starting around four to six weeks of gestation. This method is approved for use up to 10 or 11 weeks of pregnancy, depending on the specific regimen and the provider’s protocol. It is a two-step process that uses a combination of two medications to end the pregnancy nonsurgically.
The first medication taken is mifepristone, which works by blocking progesterone, a hormone necessary to sustain the pregnancy. By blocking progesterone, the uterine lining begins to break down, and the pregnancy stops developing. Most individuals do not experience significant symptoms after taking this pill and can resume their normal activities.
The second medication, misoprostol, is usually taken 24 to 48 hours later, either orally or vaginally. Misoprostol causes the uterus to contract and the cervix to soften, resulting in cramping and bleeding to expel the pregnancy tissue. This process is similar to a heavy miscarriage and is typically completed within a few hours at home or another private location. The use of both medications is highly effective, with success rates of approximately 94–98% in pregnancies that are eight weeks or less.
In-Clinic Procedural Abortion at Early Stages
In-clinic procedural abortion, often called vacuum aspiration, is a safe and common method available in the first trimester, typically starting around five to six weeks of gestation. While medication abortion can be used earlier, this procedural option may be chosen once the pregnancy is clearly visible via ultrasound or due to personal preference. The procedure is a quick, same-day, in-office process that uses gentle suction to empty the uterus.
The earliest form of this procedure is often manual vacuum aspiration (MVA), which uses a handheld syringe to create the necessary suction. The procedure begins with the use of a speculum and a local anesthetic injection to numb the cervix. A thin, flexible tube called a cannula is then carefully inserted through the cervix into the uterus.
The actual suction portion of the procedure is very fast, usually taking only two to three minutes to complete. This method offers the advantage of being over quickly, with the patient under medical supervision throughout the entire time. For some, having the procedure completed rapidly in a clinical setting is preferable to managing the process and symptoms of a medication abortion at home over several hours.