But one in three women with retained products after a medical abortion still needed surgery, a US study found.
Misoprostol was no better than monitoring for women who had retained products after a medical abortion, according to US research.
Surgery was avoided by most women in both groups, reducing the risk of scarring or trauma that could affect fertility, the authors said. However, a significant minority still needed curettage or hysteroscopy after the eight-week period.
The randomised controlled trial of 141 women with retained products found no difference in the rates of surgery among those who were given misoprostol, compared to those who underwent expectant management.
The US researchers found that rates of adverse events, pain and use of over-the-counter pain relief were also the same between the groups, over the eight-week period after termination.
“There was no clinically meaningful advantage for medical treatment with misoprostol compared with expectant management after first-trimester medical termination of pregnancy in women with suspected retained products of conception,” the authors wrote in The American Journal of Obstetrics and Gynecology.
“Surgical intervention can be avoided in up to 60% of women who are managed expectantly for eight weeks of follow-up.”
Among more than 800 women who underwent a medical abortion, 155 had retained products of conception afterwards.
This aligns with previous research that puts efficacy rates of medical abortion between 77%-92%.
The results also showed that across both groups, the only predictor of treatment outcome was the size of the retained products of conception. Product length was 20mm on average in both groups. Each 1mm increase in length carried with it a 12% increased risk the abortion would not resolve.
The findings come as medical abortions grow increasingly popular globally.
In New South Wales alone, Family Planning NSW provided 860 medical abortions between April 2020 and September last year.
“Although there is no evidence-based guideline, it is advised to remove retained products of conception in symptomatic women (ie, women with prolonged irregular bleeding) and to prevent long-term complications, such as intrauterine adhesions,” the authors wrote.
“Surgical management includes either suction curettage or operative hysteroscopy: it is the mainstay treatment of retained products of conception; however, potential complications of these interventions include uterine perforation, infection, and intrauterine adhesions.”
Determining the right time frame for follow up and surgical intervention was important, the authors said.
“Although an extension of the follow-up period from diagnosis to treatment does not seem to influence the reproductive outcome, the presence of persistent prolonged irregular bleeding together with emotional stress attributed to the presence of retained products of conception highlights the need for establishing a reasonable time frame to avoid unnecessary distress to the patients.”
American Journal of Obstetrics and Gynecology 2022, online 22 June
