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Clinical research / standards
Given the available data and other considerations, both surgical and induction methods are safe and effective options for later abortion. The choice depends mainly upon patient preference and the availability of a clinician with the skills and experience to provide one or both approaches. Surgical abortion is recommended for those who prefer a procedure with greater control over timing and less experience of the procedure and who are willing to accept a higher risk of additional surgical intervention for complications. Induction (medication) abortion is recommended for women who place a high value on avoiding surgery or have a reason to prefer an intact fetus and who are willing to accept more discomfort and awareness during the procedure and a higher blood loss. Later surgical abortion is typically performed in an outpatient setting, either a specialty women’s health clinic, physician’s office equipped with a procedure room, or an ambulatory surgery center. Medical induction most commonly occurs in hospitals on a labor and delivery unit or a family planning unit within the hospital. Induction procedures can be performed in outpatient settings, with the appropriate medical staff and equipment to provide ongoing administration of induction agents, analgesia and anesthesia, monitoring of patient status, delivery of the fetus and placenta (timing is often unpredictable), and, if needed, emergency surgical management (in case of a need for immediate evacuation of either fetus or placenta) or emergency transport to an inpatient facility. An overview of clinical research and recommendations on both procedures is provided below.
Surgical abortion, referred to as dilation and evacuation (D&E), accounts for the majority of later abortions in the United States [1-15]. The United States Centers for Disease Control and Prevention (CDC) reported that, in 2009, uterine curettage was used in 96 to 98 percent of abortions at 14 to 17 weeks of gestation, 95 percent at 18 to 20 weeks, and 91 percent at ≥21 weeks . Both surgical and induction abortion in the second trimester are safe and effective, but surgical abortion is preferred by most women and access to induction abortion is limited due to a lack of skilled clinicians and facilities [16-18]. In addition, approximately 8% of women who undergo induction abortion require a surgical procedure for retained placenta. The typical protocol for surgical termination is outlined below:
- Cervical preparation. Dilation of the cervix is required prior to D&E to allow insertion of instruments and evacuation of the uterus. Cervical dilation is typically achieved in two phases: preprocedure cervical preparation with osmotic dilators and/orprostaglandins followed by mechanical dilation with surgical dilators on the day of the procedure. Cervical preparation and dilation is started up to two days prior to the procedure using an osmotic (eg, Dilapan) or pharmacologic (eg, misoprostol) dilator to dilate and soften the cervix. If further cervical dilation is needed, this is performed with mechanical dilators (eg, Pratt, Hegar) just prior to the procedure. Osmotic dilators appear to be more effective than pharmacologic methods [24-32]. The disadvantage of osmotic dilators is that they must be placed at least a day prior to the procedure, and often are placed over two days prior to the procedure, although same day options are available . In contrast, misoprostol can be given the same day as the procedure, allowing for the procedure to be completed in one day. This decreases the expense of second trimester abortion and increases access for many patients.
- Injection to induce fetal demise. Injection of a substance to cause fetal demise prior to second trimester surgical abortion is controversial [33-36]. The advantages of this practice are that feticidal injection precludes the possibility of live birth, thereby potentially reducing emotional stress on the patient, and also allowing the surgeon to comply with legislation that penalizes uterine evacuation in which portions of the fetus are extracted prior to demise . In addition, it has been proposed that fetal demise makes the procedure technically easier by inducing fetal maceration and cervical priming. Many clinicians use such injections before all second trimester surgical abortions, while others use them only in those cases in which they consider this to have a benefit for the patient.
- Cervical dilation. Based upon the diameter of most forceps used for D&E, the minimum dilation requires ranges from 14 to 19 mm . Sufficient cervical dilation decreases the risk of morbidity, including cervical injury and uterine perforation [9, 13, 39]. Cervical preparation with osmotic dilators and/or prostaglandins accomplishes some of this dilation. Further dilation with surgical dilators is typically required. Additional dilation may also be required to remove the products of conception in advanced gestations.
- Uterine evacuation. The D&E procedure for evacuation of the fetus and placenta is performed using a combination of suction, extraction with forceps, and curettage [40-43]. After adequate cervical dilation is achieved, suction curettage is performed. Both the fetus and placenta must be entirely removed. A variant of D&E is intact D&E, also referred to as D&X. With this technique, the fetus is removed intact or nearly intact through the cervix [44-46]. The potential advantages of D&X compared with standard D&E include : (1) The likelihood of uterine perforation and cervical abrasion may be decreased because the technique minimizes the number of instrumental passes and permits direct visualization within the vagina; (2) Because the fetus is removed intact, it might also permit superior morphologic evaluation to further clarify prenatal diagnosis, although pathologic evaluation can also be performed on non-intact specimens . In the United States, the Partial-Birth Abortion Act of 2003 criminalizes some variants of D&E and provides no legal exception for cases performed to protect maternal health. Physicians should consult the provisions of the law if they intend to perform an intact extraction, and some experts advise use of preoperative feticidal injection.
Follow up. Many clinicians schedule a follow-up visit at two weeks, although most complications present before this time period. In settings where patients live a long distance from abortion facilities, it is appropriate to schedule follow-up with another clinician, to offer routine phone follow-up 24 to 48 hours afterwards, or to offer patient follow-up on an as-needed basis . The patient should be given detailed instructions regarding signs and symptoms of complications.
Medication (Induction) termination
Current protocols for later abortion typically include a prostaglandin (PG), usually misoprostol, and may utilize mifepristone or oxytocin [48-50]. A preoperative evaluation must first be performed prior to a later abortion to determine gestational age, general medical status, and any health factors that may impact the choice of medical versus surgical abortion. This involves: (1) Cervical preparation — Clinicians typically began induction termination by placing osmotic dilators in the cervix to facilitate induction through cervical ripening. This assures sufficient cervical dilation for surgical abortion if medical abortion fails or becomes excessively prolonged. This is especially true in patients with comorbidities whose medical condition may worsen and thus necessitate an expedited procedure; (2) Induced fetal demise — Clinicians induce demise prior to abortion either to facilitate the abortion procedure or to prevent live birth. Induction of demise prior to medical abortion might shorten induction to abortion interval, particularly if potassium chloride is utilized ; (3) Anesthesia — Women undergoing medical induction can receive anesthesia similar to that used for obstetric labor induction. Intermittent narcotic administration suffices for some patients, while others desire epidural anesthesia since this completely eliminates pain during more prolonged inductions.
Patients desiring medical abortion in later gestational age have safer, effective options, utilizing PG agents either alone or in combination with progesterone antagonists. The most common medications currently used for induction abortion are gemeprost and misoprostol. Studies find that both misoprostol and gemeprost induce labor more effectively and with fewer side effects than other PGs and than single-agent oxytocin or oxytocin in combination with other types of prostaglandins [49-53]. Misoprostol and gemeprost induce labor at a variety of gestational ages [54-55]. Misoprostol is typically the preferred agent due to lower rates of certain adverse effects and complications and based on practical considerations. Gemeprost and misoprostol have been found to have similar efficacy in randomized trials [54-62].
Mifepristone may be used in combination with misoprostol to decrease the induction-to-abortion interval and minimize pain [63-67]. Mifepristone elicits a variety of effects that make the uterus more susceptible to abortion. These effects include cervical dilation, decidual necrosis, increased endogenous prostaglandin production, and increasing uterine sensitivity to prostaglandin . The World Health Organization (WHO), American College of Obstetricians and Gynecologists (ACOG), Society of Family Planning, and the United Kingdom Royal College of Obstetricians and Gynaecologists (RCOG) recommend regimens in which mifepristone precedes use of either misoprostol or gemeprost [66,68-70].
Advantages and disadvantages of surgical versus medical termination
Advantages of later surgical abortion include: (1) decreased procedure duration and predictable timing – Although patients usually undergo one to two days of cervical preparation, experienced surgeons can perform uterine evacuation in less than 30 minutes once the cervix is dilated. Labor induction, by contrast, may take as long as 24 hours or longer; (2) decreased cost – D&E usually occurs in an outpatient facility. Medical induction often requires admission to a higher cost labor and delivery unit . (3) Medical conditions that required controlled timing of the procedure – The controlled timing of D&E permits planned procedures for patients whose medical conditions may worsen peripartum. Patients with bleeding diatheses, cardiac, and other maternal conditions often benefit from scheduled surgical procedures rather than less predictable induction procedures. Patients with multiple prior uterine surgeries and placenta previa can also undergo safe D&E, avoiding risks of uterine rupture or hemorrhage. Surgical abortion, however, has an elevated risk of uterine perforation compared with medical abortion – uterine perforation is a potential risk of surgical abortion and requires further surgical intervention.
Advantages of later medical abortion include an intact fetus – some patients choose labor induction to avoid fetal dismemberment associated with D&E. This may be due to a desire to hold the fetus or to provide an intact fetus for morphologic evaluation (this may be important when congenital anomalies are present). Disadvantages of later medical abortion include: (1) increased experience of the procedure – In induction abortion, the patient experiences uncomfortable effects (bleeding, cramping, nausea, vomiting) and these occur over a longer period of time during and after the procedure than with surgical abortion . The patient also has a greater awareness of the process of terminating the pregnancy. Many patients find that the predictability of surgical abortion and avoiding the memory of prolonged labor make D&E less emotionally burdensome than induction abortion [19-21]; (2) unpredictability of the timing of delivery; (3) risk of hemorrhage or infection – Second trimester induction abortion is associated with higher blood loss than surgical abortion.
[Adapted from Hammond, C. Second trimester pregnancy termination. In: UpToDate, Steinauer, J (Ed), UpToDate, Waltham, MA. (Accessed on August 26, 2015.)]
For additional clinical research and standards for later abortion provision, see the Related Research in our archive.
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