Early Medication Abortion Noninferior to Standard Treatment: New Randomized Trial Finds

The study, published in the New England Journal of Medicine, revealed that initiating medication abortion before confirming an intrauterine pregnancy is noninferior to the standard delayed treatment in terms of achieving a complete abortion.

Medication abortion, which involves taking a combination of mifepristone and misoprostol, is a well-established method for terminating early pregnancies and is considered highly effective and safe. Traditionally, the treatment begins after the pregnancy is confirmed, typically around six weeks of gestation, using ultrasound or other methods to verify the presence of an intrauterine pregnancy.

Against the above background, Karin Brandell, Karolinska Institutet, Department of Women’s and Children’s Health, Division of Obstetrics and Gynecology, Stockholm, Sweden, and colleagues assessed the efficacy and safety of medication abortion at very early gestations, before the pregnancy can be visualized through ultrasonography.

For this purpose, the researchers conducted a multicenter, noninferiority, randomized controlled trial involving women seeking medication abortion up to 42 days of gestation with an unconfirmed intrauterine pregnancy on ultrasound (visualized as an empty cavity or a sac-like structure without a yolk sac or embryonic pole). Participants were randomly assigned to either the immediate abortion initiation group (early-start group) or the standard-care group, where treatment was delayed until intrauterine pregnancy confirmation.

The primary outcome was complete abortion, with a noninferiority margin set at 3.0 percentage points for the absolute difference between the groups.

The following were the key findings of the study:

• Study Overview: 1,504 women were included in the study, conducted across 26 sites in nine countries. Participants were randomly assigned to either the early-start group (754 participants) or the standard group (750 participants).
• Primary Outcome (Complete Abortion):
  • In the early-start group, 95.2% of participants had a complete abortion.
  • In the standard group, 95.3% of participants had a complete abortion.
  • The absolute difference between groups was −0.1 percentage points, indicating noninferiority of the early-start group.
• Ectopic Pregnancies:
  • Ectopic pregnancies occurred in 1.3% of participants in the early-start group.
  • Ectopic pregnancies occurred in 0.8% of participants in the standard group.
  • One ectopic pregnancy in the early-start group ruptured before diagnosis.
• Serious Adverse Events:
  • Serious adverse events occurred in 1.6% of participants in the early-start group.
  • Serious adverse events occurred in 0.7% of participants in the standard group.
  • The majority of serious adverse events were uncomplicated hospitalizations for treatment of ectopic pregnancy or incomplete abortion.

"The study offers compelling evidence that very early medication abortion is noninferior to the standard delayed approach, with comparable outcomes and safety profiles. These results could lead to expanded access to abortion services, providing women with more options and greater flexibility in managing their reproductive health," the researchers concluded.

Reference:

Brandell K, Jar-Allah T, Reynolds-Wright J, Kopp Kallner H, Hognert H, Gyllenberg F, Kaislasuo J, Tamang A, Tuladhar H, Boerma C, Schimanski K, Gibson G, Løkeland M, Teleman P, Bixo M, Mandrup Kjaer M, Kallfa E, Bring J, Heikinheimo O, Cameron S, Gemzell-Danielsson K; VEMA (Very Early Medication Abortion) Study Group. Randomized Trial of Very Early Medication Abortion. N Engl J Med. 2024 Nov 7;391(18):1685-1695. doi: 10.1056/NEJMoa2401646. PMID: 39504520.