Laboratory : Testing for Pregnancy
The possibility of pregnancy must be considered when evaluating a patient who could become pregnant, such as a pubertal or post-pubertal female. When there is a history of unprotected intercourse, pregnancy prevention, along with appropriate counseling, can be offered.
Emergency contraception may take the form of an intrauterine device (IUD) or an oral medication. IUDs (both copper and levonorgestrel based) have the benefit of being more effective than medications because the effectiveness is not impacted by body mass index (BMI). In addition, IUDs provide ongoing contraception. However, insertion of an IUD post-assault (within 5 days) is often not acceptable to patients and may not be feasible in the emergency setting. For placement of an IUD, a pregnancy test is required, and insertion needs to be performed by a clinician.
Emergency contraceptive medications, often called morning-after pills, contain either levonorgestrel (Plan B One-Step, Fallback Solo, and others) or ulipristal acetate (ella, Logilia). Note, these medications are not considered to be abortifacients; they prevent ovulation and do not prevent implantation. A pregnancy test is generally not required prior to starting emergency contraceptive medications but is usually offered.
For maximum effectiveness, hormone medications for pregnancy prevention should be taken as soon as possible after the sexual assault, optimally within 12 hours. Ulipristal is generally most effective prior to 120 hours (5 days) post unprotected intercourse and is available only with a prescription. For lovonorgestrel, 72 hours post incident is recommended for maximum effectiveness. Lovonorgestrel is sold without a prescription, depending on local availability.
A follow-up pregnancy test should be obtained at approximately one to two weeks post incident.
