First Trimester Termination: procedure selection

Determine the methods of early abortion for which a woman is eligible based on medical and other factors. Then after the options, with pros and cons, have been objectively and thoroughly explained, help the patient select a method.

If the woman has had sufficient counselling to make an informed choice, either surgical or medical abortion can be offered.

A. MEDICAL ABORTION (≤ 8Weeks)

Research from Canada, United Kingdom, and France indicates that more than one half of eligible women opt for medical methods if given the choice. There is no medication indicated for pregnancy termination in Canada, so this method is managed with the off-label use of methotrexate followed by misoprostol or with misoprostol alone. The reported success of methotrexate in the treatment of ectopic pregnancies led Creinin and Darney, in 1993, to use methotrexate (50 mg/m2) and misoprostol (800 ìg) to induce abortion in early intrauterine gestation.

Numerous trials have demonstrated the safety and efficacy of this method, although it is less efficacious than surgical means. Unconditional follow-up is required to ensure success, and an alternative method must be available in the event of failure. The complete abortion rate is approximately 90% or more in gestations up to 49 days. For gestations of greater duration, the success rate appears to decline. (II-1A) Within 24 hours of the first or second dose of misoprostol, 78 percent of patients pass the products of conception (POC). (IA) The remainder of patients who ultimately have a successful medical termination have a delayed termination that may extend over several days.

When medical termination fails, it is mainly due to the incomplete expulsion of POC. Approximately 1% of patients will have an ongoing viable gestation that will require surgical evacuation because of the potentially teratogenic effects of misoprostol. (II-2A) There is no clear evidence that non-chemotherapeutic doses of methotrexate cause congenital anomalies.

Misoprostol alone can induce abortion in the early first trimester, although repeated doses may be required. In one study, misoprostol 800 ìg placed vaginally every 48 hours up to three doses, had a complete abortion rate of 93%.

Patient Selection

Candidates for the medical termination of pregnancy need a comprehensive screening to ensure a commitment to follow-up. The patient must be able to participate in the process, tolerate a potential delay in the termination, comprehend the instructions, and be emotionally stable. In addition, the patient must be willing to have a surgical procedure if the medical termination fails. Evidence suggests that the efficacy of medical abortion decreases with increasing gestational age; however, this method may be offered up to 56 days of gestation.