Complications and intervention
Major complications are rare with medical management of first-trimester abortion and early pregnancy loss, but can include ongoing pregnancy, which is infrequent but possible; incomplete abortion, which is easily managed; and allergic reactions, which are “extremely rare,” Dr. Prager said.
Hemorrhage can occur, but isn’t common and usually is at a level that doesn’t require blood transfusion. “But it does require somebody to come in, potentially needing uterine aspiration or sometimes just a second dose of misoprostol,” she said.
Serious infections are “extraordinarily uncommon,” with an actual risk of infectious death of 0.5 per 100,000, and therefore antibiotic prophylaxis is not recommended.
“This is not to say that there can’t be serious infectious problems with medication abortion, and actually also with spontaneous abortion ... but it’s extremely rare,” Dr. Prager said, adding that “there are also consequences to giving everybody antibiotics if they are not necessary. I, personally, am way more afraid of antibiotic resistance these days than I am about preventing an infection from an medication abortion.”
Intervention is necessary in certain situations, including when the gestational sac remains and when the patient continues to have clinical symptoms or has developed clinical symptoms, she said.
“Does she now show signs of infection? Is she bleeding very heavily or [is she] extremely uncomfortable with cramping? Those are all really great reasons to intervene,” she said.
Sometimes patients just prefer to switch to an alternative method of management, particularly in cases of early pregnancy loss when medical management has “not been successful after some period of time,” Dr. Prager added.
Outcomes
Studies have shown that the success rates with a single dose of 400-800 mcg of misoprostol range from 25% to 88%, and with repeat dosing for incomplete abortion at 24 hours, the success rate improves to between 80% and 88%. The success rate with placebo is 16%-60%; this indicates that “some miscarriages just happen expectantly,” Dr. Prager explained.
“We already knew that ... and that’s why expectant management is an option with early pregnancy loss,” she said, adding that expectant management works about 50% of the time – “if you wait long enough.”
However, success rates with medical management depend on the type of miscarriage; the rate is close to 100% with incomplete abortion, but for other types, such as anembryonic pregnancy or fetal demise, it is slightly less effective at about 87%, Dr. Prager noted.
When mifepristone and misoprostol are both used, success rates for early pregnancy loss range from 52% to 84% in observational trials and using nonstandard doses, and between 90% and 93% with standard dosing.
Other recent data, which led to a 2016 “reaffirmation” of an ACOG practice bulletin on medical management of first-trimester abortion, show an 83% success rate with the combination therapy in anembryonic pregnancies, and a 25% reduction in the need for further intervention (N Engl J Med. 2018;378:2161-70).
“So it really was significantly more effective to be using that addition of the mifepristone,” she said. “My take-home message about this is that, if mifepristone is something that you have easily available to you at your clinical site, absolutely use it, because it creates better outcomes for your patients. However, if it’s not available to you ... it is still perfectly reasonable for patients to choose medication management of their early pregnancy loss and use misoprostol only.
“It is effective enough, and that is just part of your informed consent.”