CHAPTER 3 Richard Lyus1 and Patricia A. Lohr2 1bpas (British Pregnancy Advisory Service) Richmond, East Twickenham, UK 2bpas (British Pregnancy Advisory Service), Stratford Upon Avon, UK Induced abortion is one option for managing unintended or unwanted pregnancy. An estimated 43 million abortions are undertaken each year worldwide making it the most commonly performed gynecological procedure [1]. While some intended pregnancies become unwanted, most women who have abortions did not intend to become pregnant. Data on pregnancy intention are not collected in every country, but those from the United States illustrate its relationship with the incidence of abortion. Exclusive of miscarriages, 22% of pregnancies in the US end in abortion. However, of the nearly one half that are unintended, 40% end in abortion [2, 3]. Unintended pregnancy is the result of contraceptive method failures in some cases, but most occur either because no contraception was used or because the method was used inconsistently or incorrectly [4–6]. Ambivalence about contraception or pregnancy and a perceived low risk of pregnancy have also been associated with non‐use or inconsistent use of contraception, and use of less effective methods [7]. That a pregnancy is unintended is only a first level explanation of the decision to terminate a pregnancy however [8]. Underlying that decision is typically a complex set of reasons such as interference with education, economic resources, health concerns, or relationship difficulties [9, 10]. Induced abortion using modern methods is very safe. When performed by trained clinicians with the appropriate resources, the chance of a woman dying from an induced abortion is considerably lower than chance of dying from childbirth [11, 12]. In the most recent Confidential Enquiry into Maternal Deaths in the United Kingdom, only two direct deaths related to induced abortion were recorded in the period 2006–2008 [13]. During this time, approximately 600 000 abortions would have been performed in England and Wales [14]. In contrast, when abortion is performed in unsafe conditions it is the cause of almost 70 000 deaths per year worldwide [15]. This chapter focuses on elective, induced abortion to 24 weeks gestation; termination of pregnancy for fetal or maternal indications is not considered in detail. Abortion at these gestations may be performed surgically or with medications. The choice of method is determined by multiple factors including patient preference, medical eligibility, and service availability. 1. What counseling is needed for a woman who is considering ending a pregnancy by abortion? A woman with an unwanted pregnancy may choose to have an abortion, continue the pregnancy and arrange for adoption, or continue the pregnancy and undertake parenting. Most women requesting abortion will have decided to have a termination of pregnancy before coming to a healthcare provider for assistance. While the decision may not be easy and some women may find the experience stressful, most will not require further counseling [16, 17]. Requirements for counseling may also be viewed as intrusive when a woman is certain of her decision and can result in unnecessary delays to treatment [18, 19]. An explanation of treatment options and their associated risks provided in an a supportive non‐judgmental manner and prompt referral for treatment summarizes the expectations and needs of most women once the decision to have an abortion has been made [18]. For some women, the decision to end or continue a pregnancy may not be straightforward. Feelings about whether a pregnancy is wanted are not always clear or may change over time, affected by factors such as a change in personal circumstances or antenatal screening results. Healthcare providers can help a woman consider her pregnancy options with non‐directive decision‐making support. A small proportion of women may anticipate that they will not cope well after an abortion [20]. Thus the option of supportive counseling before and after an abortion should be available if needed [21]. Importantly, whether a woman continues an unintended pregnancy or chooses to have an abortion, the mental health outcomes will be the same [22, 23]. Adverse mental health outcomes after an abortion or birth are most reliably predicted by a history of mental health problems. Referral pathways to therapeutic counseling should be in place [21]. Women who continue unintended pregnancies or are denied an abortion may also need additional support during and after their pregnancy [24–27]. For women considering abortion due to fetal abnormality or a maternal medical condition, discussion with an obstetrician, fetal medicine specialist, or pediatrician may be necessary to facilitate informed decision‐making. 2. What medical assessments are necessary before an abortion? If a woman has presented to her clinician without having performed a home pregnancy test, urine beta‐hCG testing should be undertaken [17]. Once pregnancy has been confirmed, determination of gestational age is important because the methods used for medical and surgical abortion are gestational age dependent. In addition, gestational age limits are integral to abortion law in most countries. Gestational age may be determined by ultrasound or by clinical assessment (bimanual pelvic examination and/or last menstrual period). Where ultrasound is readily available, it is often used to verify gestational age and exclude ectopic or non‐viable pregnancies or uterine anomalies. One systematic review has highlighted the lack of comparative data justifying the routine use of ultrasound prior to abortion with regard to safety and effectiveness [28]. Therefore ultrasound should not be considered a requirement. The pre‐abortion medical evaluation is not intended to assess whether a woman may safely have an abortion or not. Rather, it is focused on determining if any contraindications to choice of method or anesthesia exist, and whether the abortion needs to be performed in a hospital setting. A brief, targeted physical examination is usually sufficient and can be tailored to the anticipated treatment and the woman’s medical history. This may include height and weight (to determine body mass index), observations, cardiac, pulmonary, abdominal, and pelvic examinations. Blood testing is typically limited to determination of Rhesus (D) antigen status [21]. Administration of anti‐D immunoglobulin is recommended for Rh negative women, unless the father of the pregnancy is known to be Rh negative [29]. Hemoglobin determination is often undertaken where there is a concern for anemia or if significant blood loss anticipated although data to support this practice are limited [30]. Opportunistic screening for sexually transmitted infections or abnormal cervical cytology is also a frequent recommendation [21, 31]. 3. What are the methods of abortion in the first trimester of pregnancy and which is optimal? In both the first and second trimesters, abortion may be performed surgically or achieved by the administration of abortifacient medications. In the first trimester, the main surgical techniques are vacuum aspiration and dilation and sharp curettage (D&C). Cochrane meta‐analyses have found few statistically significant differences between these methods. However, vacuum aspiration was shown to be faster than D&C when used for abortion and to be faster and associated with less pain and bleeding when used for miscarriage management [32, 33]. An additional advantage of vacuum aspiration is that it may be undertaken in an office setting under local anesthetic. Dilation and curettage is conducted in an operating theater with general anesthetic requiring greater resources [21, 34]. Vacuum aspiration may be performed using a manual or electrical suction device. Randomized comparisons have found no differences between electric and manual vacuum aspiration in terms of complications or patient preference, but more clinicians report difficulty with manual vacuum aspiration after nine weeks gestation [35]. One study found that significantly more women are bothered by the noise associated with electric vacuum aspiration [36]. Medical abortion allows a woman to have a safe, effective termination of pregnancy without a surgical procedure. Early medical abortion refers to the use of abortifacient medications up to 63 days gestation, although some regimens are effective beyond 63 days. In the past, medical abortions were performed only in the second trimester using intra‐amniotic instillation of hyper‐osmolar agents or prostaglandins [35]. The development of prostaglandin analogues that could be administered vaginally or by injection made medical abortion possible earlier in pregnancy [37]. However the need to administer the medication in a hospital setting and a high incidence of gastrointestinal side effects and pain limited their use. The introduction of the anti‐progestogerone mifepristone in the late 1980s led to a transformation in early medical abortion care. Mifepristone causes cervical softening, decidual necrosis, and increased myometrial sensitivity to prostaglandins [38]. Initially studied for use alone in very early pregnancy, mifepristone was found to be only 60–80% effective [38]. When administered 36–48 hours before a prostaglandin analogue, however, the efficacy increased to nearly 100%. Multiple randomized trials have since demonstrated that the combination of mifepristone and a prostaglandin analogue is the most effective regimen for early medical abortion [39]. Defined as a complete abortion without resort to surgical intervention, success is upwards of 95% in most studies [39]. The most widely used and recommended prostaglandin analogue for medical abortion is misoprostol [21, 40]. Gemeprost (16, 16‐dimethyl‐trans‐delta2 PGE1 methyl ester) is a vaginally administered prostaglandin analogue that was initially approved for use with mifepristone in Europe. Although effective to 63 days gestation, it is expensive and requires refrigeration. Misoprostol, in contrast, is inexpensive, stable at room temperature, and can be administered by a variety of routes including oral, vaginal, sublingual, and buccal. Compared to Gemeprost, misoprostol administered vaginally has a similar side effect profile and is more effective to 63 days gestation [41]. Initial studies of medical abortion with 600 mg mifepristone and 400 mcg oral misoprostol were limited to gestations up to and including 49 days. When evaluated beyond 49 days gestation, oral misoprostol was shown to be associated with an unacceptably high failure rate [42]. A dose of 800 mcg misoprostol administered vaginally was, however, shown to be as effective at all gestations up to and including 63 days with a faster onset of action and fewer side effects [43, 44]. Vaginal administration was also shown to allow for a flexible dosing interval between mifepristone and misoprostol of anywhere from 6 to 72 hours without a decrement in effectiveness [45]. More recent studies have investigated misoprostol administered sublingually and buccally, which are also effective and acceptable routes of administration [42]. Reducing the dose of mifepristone from 600 to 200 mg is as effective in inducing a complete abortion [42]. Most early medical abortions are undertaken outside of a medical facility. Women are given tablets of misoprostol to take home and use within a specified interval, followed by abortion at home. A large body of evidence demonstrates that this is safe, effective, and acceptable to women [46]. Where mifepristone is not available, misoprostol may be used alone for early medical abortion. However multiple doses are often required and the success rate is lower, ranging from 85% to 90% in most studies [42]. The anti‐dihydrofolate reductase agent methotrexate can also be used in combination with misoprostol up to 56 days gestation. Rather than acting as an abortifacient, the main effect of methotrexate is to cause embryonic demise. Methotrexate‐based regimens have a less reassuring safety profile than those with mifepristone, require a longer interval before administration of the prostaglandin, and are about as effective as misoprostol alone [42]. A Cochrane review of six studies comparing medical and surgical methods in the first trimester found the rate of abortions not completed with the intended method to be significantly higher in the medical abortion group (OR 2.7, 95% CI 1.1, 6.8) [47]. There was no difference between the groups for ongoing pregnancies or pelvic infections, but one major complication, a uterine perforation, was reported in the surgical group. Duration of bleeding was longer with medical as compared to surgical abortion, but only rarely does this result in anemia requiring transfusion. In one large retrospective review of approximately 80 000 women undergoing early medical abortion, only 13 patients required blood transfusions [48]. Data on acceptability, side effects, or women’s satisfaction with the procedure were not available for inclusion in the Cochrane review. One randomized trial comparing early medical abortion with mifepristone and misoprostol to vacuum aspiration under general anesthetic up to 14 weeks gestation was published following the Cochrane review [49]. This study validated the finding of a longer duration of bleeding with early medical abortion. It also found while most women having an early medical abortion were satisfied with their care, acceptability was lower than with vacuum aspiration particularly as gestational age increased. Cohort studies have shown that acceptability and satisfaction with both medical and surgical abortion is greatest when women are able to receive the method of their choosing [50]. 4. What are the methods of abortion in the second trimester and which is optimal? Surgical abortion can be performed with electric vacuum aspiration up to 16 weeks gestation using large‐bore suction cannula and tubing [51]. However, the most commonly used method of surgical abortion in the second trimester is dilatation and evacuation (D&E). This procedure is characterized by the attainment of wide cervical dilation and the use of crushing forceps remove the fetus and placenta. Cervical dilation is usually achieved by inserting slowly expanding synthetic or natural cervical tents several hours before the procedure or with the use of medications such as mifepristone or misoprostol that soften the cervix making manual dilation easier. Following extraction of the fetus and placenta, a vacuum aspiration is performed to remove any remaining blood and tissue. Outdated surgical abortion methods include hysterotomy and hysterectomy. These are only used in modern abortion care when a transcervical approach is not possible [52]. Obstruction by a large, distorting cervical or uterine tumor is one example of when these methods might be employed. Medical abortion in the second trimester also necessitates the passage of a larger fetus through a more dilated cervix and usually requires repeated administration of medications. The process is sometimes referred to as medical “induction” abortion as it mimics induction of labor. Older methods include intra‐ and extra‐amniotic instillation of hypertonic solutions or prostaglandin, trans‐cervical insertion and insufflation of a Foley balloon, and intravenous or intramuscular prostaglandins or oxytocics. Randomized trial data support the use of modern prostaglandin analogues with mifepristone as the most efficacious with the shortest induction to abortion interval [53]. The induction to abortion interval is usually defined as the time between the administration of medications and the passage of the fetus. In some studies, the time is extended to include the passage of the placenta which can occur several hours later. As with early medical abortion, second trimester medical abortion involves the administration of mifepristone followed by a waiting period, typically of 24–48 hours. Women are then given repeated doses of a prostaglandin analogue to induce labor. Misoprostol is most commonly recommended but Gemeprost is an alternative [21, 54]. The median induction to abortion interval with a combined regimen is 6–8 hours in most studies. Prostaglandin analogues, like misoprostol, may also be used alone; however the median induction to abortion interval is increased significantly to 12–16 hours [53]. A Cochrane review comparing medical and surgical methods in the second trimester identified two randomized trials only one of which compared D&E to medical abortion with mifepristone and misoprostol [55]. Due to difficulties in recruitment, this study was underpowered to detect a difference in individual complications between the methods. Nevertheless, this study found a lower overall rate of adverse events in the D&E group (OR 0.06, 95% CI 0.01, 0.76). These adverse events were limited to presumed infection and retained placental tissue. Fewer subjects randomized to D&E required overnight hospitalization. Although women treated with mifepristone and misoprostol reported significantly more pain than those undergoing D&E, efficacy and acceptability were the same in both groups. A more recent trial randomized 122 women at 13–20 weeks gestation to medical induction with mifepristone and misoprostol or surgical evacuation [56]. In this study, vacuum aspiration was performed up to 15 weeks gestation and D&E beyond. There were several statistically significant findings favoring surgical abortion. Women found surgery more acceptable and compared with medical induction and more women would opt for the same procedure again (100% versus 53%). Fewer women in the surgical arm found the experience worse than expected (0% versus 53%). Women who had medical induction also experienced more bleeding and pain. Similar to previously published randomized trials of medical and surgical abortion in the second trimester, a large proportion of women eligible to participate declined enrolment because they had a strong preference for a surgical abortion method. A systematic review of the available cohort studies and case‐series concluded that, given trained providers and where otherwise feasible, D&E is preferable to medical abortion in the second trimester, based on an overall lower rate of complications and patient preference [57]. In addition, D&E is quicker and less costly than medical abortion in the second trimester [58]. Traditionally, abortion for fetal abnormality or death has been accomplished by medical induction, as this practice allows pathological examination of the intact fetus. However, retrospective studies have demonstrated that there is a role for D&E in this setting based on greater safety and effectiveness [59, 60]. Genetic abnormalities are able to be confirmed without an intact fetus as are most structural anomalies [60–62]. Importantly, where women are given a choice of methods, grief resolution is the same with either a medical or surgical abortion for fetal anomaly [63]. 5. What are the risks associated with surgical and medical abortion? What can be done to mitigate abortion‐related risks? Complications with surgical abortion are very low at any gestational age. Among 170 000 first trimester vacuum aspirations performed in low‐risk women, minor complications occurred in 8.5 per 1000 cases and complications requiring hospitalization in 0.7 per 1000 cases [64]. D&E has a similar low rate of complications although the risk of a major complication increases with gestational age [65, 66]. A history of two or more Cesarean deliveries has been shown to be the strongest predictor for having a major complication with D&E (OR 7.4, 95% CI 3.4, 15.8) [66]
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