Menstrual regulation in the United States: a preliminary report.

The efficacy and safety of vacuum aspiration on an outpatient basis without anesthesia or cervical dilatation within 14 days of a missed menstrual period was evaluated in 1,009 women. Among those patients in whom pregnancy could be documented (54.8%), 4.2% were still pregnant after the procedure. Potentially serious complications were pelvic infection (0.4%), bleeding requiring a repeat curettage (0.3%), and prolonged bleeding (0.7%). For comfort, 26.7% received local anesthesia or analgesia. To allow selection of a higher proportion of pregnant patients, the probability of pregnancy was derived for patients with either a positive or negative pregnancy test at each length of amenorrhea. To determine the best vacuum pressure and source, and the cannula size and type at each duration of pregnancy, a more extensive (large, controlled, comparative) study is required.