First- and Second-Trimester Termination of Pregnancy
Anitra Beasley
Ambica Sastry
GENERAL PRINCIPLES
Definition
Termination of pregnancy, also commonly referred to as abortion or induced abortion, is an intervention used to disrupt a pregnancy so that it does not result in live birth.
Pregnancy termination may be completed with medication or vacuum aspiration in the first trimester and dilation and evacuation (D&E) or, rarely, hysterotomy during the second trimester.
Vacuum aspiration, commonly termed dilation and curettage (D&C), includes manual vacuum or uterine aspiration (MVA/MUA) and aspiration with electric suction (EVA). By strict definition, D&C involves cervical dilation followed only by metallic sharp curettage. Uterine evacuation using sharp curettage alone is no longer routinely performed for pregnancy termination in most settings and should not be used as a standalone abortion procedure (1).
Nonoperative Management
Medication abortion and medical induction are nonoperative options for pregnancy termination in the first and second trimesters, respectively.
Medication abortion refers to the use of medications for pregnancy termination, normally, through 70 days’ gestation. The combination of oral mifepristone and vaginal, buccal, or sublingual misoprostol is most effective (2) and should be used when legal and accessible (1). Follow-up evaluation is usually scheduled within 14 days of mifepristone administration to verify abortion completion and may be required by law.
Induction abortion refers to the termination of pregnancy by provoking uterine contractions with medications and subsequent delivery of the fetus and placenta. The combination of mifepristone and misoprostol is the most effective and the regimen of choice for pregnancy termination. Misoprostol alone may be used when mifepristone is unavailable (1,3).
The method of pregnancy termination is determined mainly by patient preference and clinician ability to provide one or both methods. In certain circumstances, such as very early pregnancy, conditions that limit visualization of the cervix, uterine anomalies that make access to the pregnancy infeasible, and/or poor surgical candidacy, medication or induction abortion may be the preferred option. In the second trimester, induction abortion also may be preferred when there is a desire to hold the fetus or in cases where physical evaluation or autopsy would be helpful.
IMAGING AND OTHER DIAGNOSTICS
Routine imaging for the determination of gestational age is not required for safe early abortion care (1). Gestational age can be estimated with menstrual history and bimanual examination or through ultrasonography. Although sonography is not mandatory, use is recommended with uncertain menstrual dates, discrepancy between the uterine size and menstrual dates, and in situations concerning for ectopic pregnancy (4).
Ultrasound confirmation of gestational age is recommended before pregnancy termination in the second trimester.
PREOPERATIVE PLANNING
Institutional policies, state, and federal laws regulate and may place limitations on abortion care. Clinicians should be
knowledgeable about regulations governing the termination of pregnancy in their practice area.
Counseling and informed consent
Before termination, the patient should have an opportunity to discuss and consider all pregnancy options including continuing pregnancy and parenting, adoption, and abortion.
The patient should be provided with information about available methods at and beyond the current gestational age and the risks and benefits of each method.
The desire to have an abortion should be confirmed as well as voluntary and informed consent.
Laboratory evaluation typically includes pregnancy confirmation with urine pregnancy testing or ultrasound, determination of Rh(D) antigen status, and hemoglobin and/or hematocrit. Patients with acute or chronic illnesses may require a more extensive assessment.
Cervical preparation with pharmacologic agents or osmotic dilators (Table 3.2.1) is usually necessary before second-trimester procedures to allow passage of instruments, prevent injury, and facilitate removal of tissue (5). Similar preparation is not routinely used in the first trimester as the risk of uterine perforation or cervical laceration is small. Additionally, routine first-trimester use unnecessarily delays the procedure, is associated with uncomfortable side effects, and does not confer proven benefits. There are some instances, however, where cervical preparation in the first trimester should be considered: Gestational age ≥12 weeks, adolescents, and when cervical dilation is expected to be challenging (6). Cervical preparation is a consideration in patient scheduling and procedure timing as medications and dilators may need to be given or placed hours to days before the actual procedure.
Table 3.2.1 Cervical Preparation | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ||||||||||||||
SURGICAL MANAGEMENT
Patients terminate pregnancies for many reasons, but the indication for termination of pregnancy is the voluntary desire to do.
Although some women may have an increased risk of complications owing to medical comorbidities, contraindications to uterine evacuation are rare and include the inability to give informed consent. Ongoing pregnancy and delivery are usually associated with similar complications and risk, which increases as pregnancy progresses.
Infection prevention: Prophylactic antibiotics are recommended to prevent infection in patients undergoing operative abortion, but adherence to aseptic technique should not be overlooked. Sterility of instruments that pass through the cervix must be maintained, but sterile gloves are not required if a no-touch technique is used. Antibiotics should be given as a single dose within 1 hour before the procedure, with doxycycline 200 mg as the preferred antibiotic regimen. Metronidazole 1 g or azithromycin 500 mg are appropriate alternatives (7,8).
Pain management: Safety and patient preference should direct the choice of anesthetic medications and techniques. A combination of modalities, including preoperative nonsteroidal anti-inflammatory drugs (NSAIDs), local anesthesia, and nonpharmacologic interventions such as verbal reassurance, can be used to reduce pain and improve patient satisfaction (1,9). Moderate or deep sedation or general anesthesia may offer enhanced pain control (1) and improve operative conditions for the surgeon by facilitating muscle relaxation and visualization (10).
Rh(D) immune globulin: Rh(D) immune globulin should be given to unsensitized women who are Rh(D)-negative to prevent alloimmunization (11).
Positioning
Uterine aspiration and D&E procedures are performed with the patient in the dorsal lithotomy position.
Approach
The choice of procedure depends on gestational age, patient preferences, medical comorbidities, and clinician experience.
Uterine aspiration is typically used to evacuate pregnancies up to 14 weeks gestation; however, some providers offer vacuum aspiration further into the second trimester. Evacuation of more advanced gestations requires the use of forceps, especially after 15 to 16 weeks of gestational age.
MVA versus EVA: Manual vacuum aspirators are small, quiet, and easy to transport handheld syringe-like devices that create up to 60 mm Hg of suction. The MVA is more portable and less expensive than the EVA and does not require electricity, making it useful in resource-limited settings. There is no clear gestational age at which MVAs are no longer appropriate for uterine evacuation, but as gestational age increases, the MVA may need to be repeatedly emptied. For this reason, some providers prefer to switch to using electric suction at 8 or 9 weeks gestation (4).
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
