Expected Side Effects of Medical Abortion

This page contains the following sections:

Pain and Cramping
Gastrointestinal Side Effects
Thermoregulatory Changes
Headache and Dizziness
Follow-up After Medical Abortion


After reading this section, you should be able to answer the following question:

What are some general characteristics of side effects and complications associated with medical abortion?

Many of the side effects of medical abortion are expected and generally minor. During the course of a medical abortion, nearly all women experience pain resulting from uterine cramping, and bleeding, often with passage of clots. Nausea, vomiting, and diarrhea are frequent side effects of misoprostol, although these gastrointestinal symptoms have also been reported after mifepristone or methotrexate.

Thermoregulatory effects, such as warmth, hot flushes, fever, and chills, can occur following misoprostol administration, although vasomotor changes relating to hormonal fluctuations may also cause some of these symptoms.

In specific cases, it is often difficult to determine if side effects occurring during the process of medical abortion are caused by the medications or by the process of aborting itself.

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After reading this section, you should be able to answer the following question:

Which technique is NOT suitable for the treatment of pain associated with medical abortion?

Pain and Cramping
Pain resulting from uterine cramping is an expected part of the abortion process. Studies employing the methotrexate/misoprostol regimen for medical abortion have reported cramping in more than 75% of women.10-13

Spitz and colleagues3 conducted the largest clinical trial of mifepristone 600 mg plus oral misoprostol 400 µg in women with pregnancies of ≤ 63 days' gestation and reported that nearly all the women (≥ 96%) experienced abdominal pain. In this study, women remained in the clinic for 4 hours of observation after taking the misoprostol. Sixty-eight percent of women received at least one pain medication (usually acetaminophen), and 29% also received opiates. Women whose gestation was ≥ 50 days received analgesics significantly more often than those whose gestation was ≤ 49 days (p < .001).

The severity of cramping pain associated with medical abortion ranges from mild to severe. The amount of discomfort a woman reports will be affected by both individual and cultural factors. In the U.S. trial using the FDA-approved regimen of mifepristone and misoprostol, Spitz and colleagues3 found no association between the incidence of pain and gestational age; however, women who were at 50 to 63 days' gestation were more likely to report the pain as severe than were women at ≤ 49 days' gestation.

Pain generally peaks after administration of misoprostol and resolves soon after completion of the abortion. In one study involving a regimen of mifepristone and oral misoprostol that tracked this side effect, Peyron and colleagues14 found that pain began less than 1 hour after the administration of misoprostol and lasted 1 hour or less.

Another study using two different mifepristone/oral misoprostol regimens found that the mean onset of cramping was 1.4 to 2.9 hours after the initial dose of misoprostol, depending on the regimen.15 In studies using methotrexate and misoprostol, pain began an average of approximately 3 hours after misoprostol administration.10,11

Pain is rarely a sign of an impending complication. However, providers should instruct patients to contact the office whenever pain is accompanied by other signs or symptoms, such as fever, anxiety, or heavy bleeding. Persistent pain warrants an evaluation to rule out underlying pathology, such as infection.

While analgesics play a role in medical abortion, one of the primary means of managing pain is through adequate counseling before the procedure and reassurance during the process. During the preparatory phase, counselors should inform patients that they may experience cramping comparable to an early miscarriage. This will allow women to prepare for the experience mentally, emotionally, and logistically (i.e., by having comfort measures ready). Whenever a provider manages a complaint of pain over the phone, recontacting the patient within a few hours is prudent to ensure that the pain has resolved.

Both non-narcotic and narcotic analgesics have been used for pain control in medical abortion. Providers should consider giving the patient either the actual medication or a prescription for analgesics at the visit when mifepristone (or methotrexate) is administered.

Suitable non-narcotic medications include acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and naproxen. NSAIDs do not interfere with the action of misoprostol. Although NSAIDs inhibit prostaglandin synthetase, an enzyme involved in prostaglandin synthesis, they do not block the effect of exogenous prostaglandin analogues such as misoprostol.16

Click here to read Case Presentation 1.

Narcotic analgesics, such as codeine or oxycodone, may be used in combination with non-narcotic drugs. In the United States, approximately 25% of women undergoing medical abortion in a clinic setting will request narcotic analgesics.3 In addition, many women find that placing a heating pad or hot water bottle on the lower abdomen can help relieve cramping.

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After reading this section, you should be able to answer the following questions:

Which approaches are appropriate if the woman is experiencing what she describes as "heavy bleeding" but denies faintness, dizziness, or other symptoms?

What were the general findings in relation to bleeding in the U.S. clinical trials of the FDA-approved mifepristone/ misoprostol regimen?

Bleeding associated with medical abortion is typically the greatest single source of concern for both patients and providers.2 The amount of bleeding considered normal during a medical abortion usually exceeds menstrual blood loss.17 The quality of bleeding may differ from menstrual bleeding as well. Women often pass blood clots during expulsion of the pregnancy, an event that may alarm women if they are not adequately apprised of this possibility.

In large-scale clinical trials, vaginal bleeding occurred in virtually all women whose pregnancy was successfully terminated with mifepristone and misoprostol.3,14 While bleeding is an expected side effect of medical abortion, excessive bleeding causing a clinically significant change in hemoglobin concentration is uncommon,17,18 as is the need for transfusion or surgical aspiration to achieve hemostasis.

In a large multicenter trial involving 2,000 women who received mifepristone 200 mg followed by 800 µg of misoprostol intravaginally, 0.4% of patients required surgical aspiration to control bleeding.19 (Note: This regimen differs from the FDA-approved regimen.) In the U.S. multicenter trial involving 2,121 women reported by Spitz and colleagues,3 which employed the current FDA-approved regimen, 2.6% of women required suction curettage to treat excessive bleeding.

The percentage of women requiring transfusion has been 0.2% in multiple large trials.3,19,20 Therefore, clinically significant bleeding is a real, albeit infrequent, problem. In one study, Creinin and colleagues reported that heavier episodes of bleeding (requiring ≥3 pads in one hour) occurred less frequently in women who used misoprostol 6-8 hours after mifepristone as compared to those who used it 24 hours after mifepristone (13% vs. 19%).There were no differences between groups in the incidence of transfusion (one in each group) or in perceived bleeding on a visual analog scale.21 The risks of this complication may also be lower in women ≤ 49 days' gestation compared to women at > 49 days' gestation.3 There have been no reports of the need for hysterectomy to control bleeding after a medical abortion.2

The duration of vaginal bleeding following medical abortion with mifepristone and misoprostol varies among studies. Clinical research conducted in the United States indicates a mean duration of bleeding of 14 to 17 days, with a range of 1 to 69 days.3,4,22-24

In the classic study by Spitz and colleagues,3 the proportion of women who reported heavy bleeding was highest on the day of misoprostol administration, and then decreased steadily over the subsequent days. Thirteen days after misoprostol administration, 77% of women described their bleeding as "spotting," and at treatment day 30, only 9% of women reported some type of bleeding. This percentage dropped to 1% by 58 days.

A comparative study of surgical abortion and medical abortion with mifepristone/misoprostol found that women generally experienced bleeding for a longer period of time following medical abortion, although post-treatment changes in hemoglobin values were comparable with the two methods.18

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Anticipatory guidance about normal and abnormal patterns of bleeding decreases the likelihood that bleeding will be anxiety-provoking.10 Adequate counseling also ensures that women will report excessive bleeding in a timely manner. A recommended guideline instructs women to contact their provider if they soak through 2 thick full-sized sanitary pads per hour for 2 consecutive hours.25

Since women may be understandably anxious about viewing the products of conception, counselors should inform medical abortion patients that fetal tissue would not be identifiable until after 8 weeks' gestation. They may see a gestational sac that looks somewhat like a grape, or they may see only blood clots.

All providers must have clear, documented procedures for evaluation and triage of potentially abnormal bleeding, including emergency assistance. Click here to view Figure 2.

If a patient complains of heavy or persistent bleeding, the clinician should detail the extent and duration of bleeding. When the patient's answers indicate a normal amount of bleeding (i.e., saturating less than 2 sanitary pads per hour), the provider can reassure the patient and follow her progress by phone. If the patient reports somewhat heavier bleeding (e.g., saturating 2 or 3 pads per hour for 2 hours) following misoprostol administration, close monitoring by phone may also be appropriate if she otherwise feels well.

Click here to read Case Presentation 2.

Acute hemorrhage, prolonged heavy bleeding, or reported symptoms of orthostasis warrant prompt evaluation. These situations might require suction curettage to control bleeding or, rarely, a transfusion.

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After reading this section, you should be able to answer the following question:

What is true about GI symptoms after medical abortion?

Gastrointestinal Side Effects
Gastrointestinal side effects, although typically thought to be related to the prostaglandin analogue (misoprostol), can also result from mifepristone4,22 or methotrexate.10,11,26 Nausea, vomiting, and diarrhea also can be associated with both early pregnancy and the abortion process itself.

In many medical abortion studies, nausea is the most commonly reported gastrointestinal side effect.3,6,14 Rates of gastrointestinal side effects are roughly the same for mifepristone/misoprostol and methotrexate/misoprostol regimens.2,3,10,11,14,22,26,27

Typically, nausea, vomiting, and diarrhea are self-limited and of mild severity. Gastrointestinal side effects are primarily managed with reassurance but also may be treated with antiemetics or antidiarrheals. However, no definitive studies prove the benefit of these interventions in medical abortion patients.

Click here to read Case Presentation 3.

Research indicates that the incidence of gastrointestinal side effects tends to increase with higher doses of misoprostol, routes of more rapid absorption, and advancing gestational age. Nausea and vomiting are significantly more frequent in women with gestations 50 to 63 days than in women with gestations ≤ 49 days (p < 0.001).3 (Note: The FDA-approved regimen is for pregnancies ≤ 49 days.)

El-Refaey and colleagues27 reported that the incidence of vomiting (31% vs. 44%; p = 0.04) and diarrhea (18% vs. 36%; p = 0.002) was significantly lower in women receiving vaginal misoprostol than among those given oral misoprostol. The typical initial dose of vaginal misoprostol in both mifepristone and methotrexate regimens is 800 µg.

The side effect profile of buccal administration, when compared to vaginal administration, has been reported to be similar, although in one study rates of diarrhea were significantly higher.62 More recently, however, Winikoff et al. reported that women's experiences of side effects following buccal use were quite similar to those following oral use, with the exception of higher rates of thermoregulatory effects in the buccal group.63

Sublingual misoprostol, with its rapid absorption and high peak serum levels, appears to be associated with higher rates of fever, chills, and gastrointestinal symptoms compared to other routes of administration.64-66

The length of the interval between mifepristone and misoprostol may also be a factor; Creinin and colleagues reported that nausea and vomiting were lower in women who used misoprostol vaginally 6-8 hours after mifepristone as compared to those who used it by the same route 24 hours after mifepristone.21

In the case reports of rare Clostridium-related sepsis following medical abortion, symptoms of severe nausea and vomiting have begun more than 24 hours after the administration of misoprostol.59-61 By contrast, normal side-effects of the medications can be expected to occur within the first several hours, tend to be short-lived, and resolve spontaneously.

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Thermoregulatory Changes
The term "thermoregulatory changes" refers to fever, chills, or a sensation of warmth that may occur during the medical abortion process. Short-term temperature elevations or chills can result from any of the medications used in medical abortion or from hormonal fluctuations.2 The reported incidence of thermoregulatory changes varies considerably across studies and depends on the parameter being measured (fever, warmth, chills).

Spitz and colleagues3 reported fever in 4% of women using the FDA-approved mifepristone/misoprostol regimen. With the regimen of methotrexate followed by vaginal misoprostol, Creinin and colleagues11 reported subjective fever or chills in 15% of subjects after methotrexate and 31% of subjects after misoprostol. Another study by Creinin and colleagues28 using oral methotrexate and intravaginal misoprostol reported fever, warmth, or chills in 30% to 44% of women. Almost all studies of mifepristone-misoprostol abortion describe side effects of fever and chills, commonly associated with misoprostol use, regardless of route of administration.

Thermoregulatory changes do not usually require treatment, as they are commonly brief in duration. When necessary, providers can treat fever with acetaminophen or NSAIDs.16 A fever of 100.4 degrees Fahrenheit or higher that persists for several hours despite the use of antipyretics, or develops days after misoprostol use, may indicate infection. Infection is a rare complication that can occur days after a medical abortion. Acute infection during the expulsion process has not been reported to date.2

Headache and Dizziness

Headache and dizziness are side effects reported by approximately 20% of medical abortion patients.2 When a patient who is bleeding heavily reports dizziness, the clinician should consider the possibility of significant blood loss causing hypovolemia. The clinician should query the patient further about the quantity of bleeding and associated symptoms such as weakness, diaphoresis, and presyncope. Patients experiencing these types of symptoms with heavy bleeding require prompt medical evaluation.

Click here to read Case Presentation 4.

Most commonly, dizziness is a mild symptom that resolves spontaneously. It can be managed with rest, hydration, gradual position changes, and assistance with ambulation. Headache can be managed with analgesics. There have been no reports of cerebrovascular accidents associated with the use of mifepristone, methotrexate, or misoprostol.2

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Follow-up After Medical Abortion
Follow-up of all medical abortion patients is critical to determine if the abortion is complete and to check for complications. During counseling for medical abortion, the clinician should confirm the date and time of the follow-up appointment and provide the patient with written instructions. The schedule for this visit will vary depending on which medical abortion protocol is employed; in most cases, it should be within 2 weeks of administration of mifepristone or methotrexate.29 Click here to view Figure 3.

The choice of medical abortion does not rule out the possible need to undergo a surgical abortion. Misoprostol, a standard component of medical abortion regimens used in the United States, is associated with teratogenic risks. Therefore, surgical abortion is required whenever the medical treatment does not successfully terminate the pregnancy.

The follow-up visit also provides an opportunity for the patient to decide on contraceptive options and for the health care provider to offer other related health services as needed. Furthermore, this meeting enables the provider to enhance his or her clinical acumen and sensitivity by learning about the patient's experience, and also can help the patient achieve a sense of closure.

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Proceed to Complications of Medical Abortion.

References for this module