Summary of MVA Performance
Mechanism of Action. A cannula is attached to the vacuum aspirator and inserted through the cervix. The contents of the uterus are aspirated using vacuum equivalent to that produced by an electric vacuum aspiration pump. Indications for Use.
MVA is an appropriate technique for induced abortion, spontaneous abortion, men- strual regulation, treatment of incomplete abortion, and endometrial biopsy. Effectiveness. For uterine evacuation: Studies show that vacuum aspiration (including MVA) typically has more than a 98 percent rate of effectiveness. Safety .Complication rates for the four major complications most commonly associated with uterine evacuation (excessive blood loss, pelvic infection, cervical injury and uterin perforation) are lower for vacuum aspiration than for Ipas flexible cannulae used with MVA. MVA uses a handheld vacuum source with a plastic cannula to perform uterine evacuation. A vacuum equivalent to that produced by the electric pump used in electric vacuum aspiration (EVA) is transferred into the uterine cavity. MVA is as safe and effective as EVA, and has been used for decades (Greenslade et al., 1993b). MVA is Very Effective for Abortion Research over the past 30 years has studied vacuum aspiration in more than 400,000 cases, in more than two-dozen countries and over 50 studies. The findings are clear vacuum aspiration is safe and effective for first-trimester abortion. The body of literature reveals that vacuum aspiration’s effectiveness ranges from 87 to 100 percent. In most of these studies the method's effectiveness rates exceeded 98 percent. (Greenslade et al., 1993b; Hemlin and Möller, 2001; Freedman et al., 1986; Westfall et al., 1998; Creinin,
2000; Edwards and Creinin, 1997). More studies have examined the effectiveness of electric vacuum aspiration than manual aspiration. Because the mechanisms of action and level of vacuum for the two methods are the same (Balogh, 1983; Freedman et al., 1986; Roy, 1974), however, effectiveness data for EVA is applicable to MVA. In several studies where both MVA and EVA were used, the two methods had equivalent rates of effectiveness (Hemlin and Möller,2001; Balogh, 1983;Freedman et al., 1986). Twelve research reports over 25 years have specifically examined the effectiveness of MVA for induced abortion, gathering data on almost 20,000 women. In these studies, MVA’s effectiveness ranged from 95 to 100 percent. In the largest study, Laufe analyzed complication rates associated with 12,888 MVA procedures in 21 countries. The procedure’s effectiveness was greater than 98 percent (Laufe, 1977). (See Table 1 forresearch reports examining MVA’s effectiveness.)
MVA for Early Abortion
In countries such as Bangladesh and Vietnam, MVA has been used for several decades to provide early abortion and menstrual regulation before confirmation of pregnancy. Prior to the mid- 1990s, however, there were few documented studies on the use of MVA before the seventh week ofpregnancy, due in part to the difficulties in confirming pregnancy at this early stage. The advent of new, highly sensitive pregnancy-detection tech- niques has encouraged many providers to adopt MVA for early abortion. The procedure is being used in countries such as the United Kingdom, the United States and South Africa to offer women the option of having an abortion early in pregnancy. In the United States, MVA before the seventh week of pregnancy was first described in 1995 by Dr. Jerry Edwards, Medical Director of Planned Parenthood of Houston and Southeast Texas. Dr. Edwards’ method combines MVA with sensitive pregnancy tests, transvaginal ultrasound and on-site tissue
inspection to provide abortion as soon as the pregnancy is confirmed. Edwards’ research indicates that MVA for early abortion is 99.2 percent effective.—Benson et al., 2001; Edwards Ipas’s MVA instruments have been shown to be particularly effective in providing first-trimester abortions. A study compared the Ipas double-valve aspirator with other vacuum sources used at centers in Bangladesh, Southeast Asia and Yugoslavia. The Ipasaspirator proved as safe and effective as the other methods (Balogh, 1983). Where medical abortion is available, it is appropriate to offer women a choice betweenMVA and medical abortion. MVA is also very effective in serving as back-up when medical abortion fails. Between two and 10 percent of medical abortion patients require a surgical procedure either because of patient request or incomplete abortion (MacIsaac and Darney, 2000). In most instances, MVA offers a simple and inexpensive way to provide back-up on an outpatient basis and in the same clinical setting as the medical abortion. Medical abortion providers who are able to perform back-up surgical abortion services can offer patients another choice among first-trimester procedures. Studies in countries as diverse as India, the United States, Vietnam and the United Kingdom have all shown that vacuum aspiration is extremely effective in providing first-trimester induced abortion. Further, effectiveness rates remain high, regardless of the country’s medical system or level of development. Vacuum Aspiration is Very Safe for Induced Abortion Vacuum aspiration is one of the safest surgical procedures available, and the safest way to perform first-trimester abortion. Vacuum aspiration can be used for almost all patients.
Providers should always follow any prescribed precautions for medications and procedures. The conditions requiring precautions for MVA procedures are similar to those of other surgical first-trimester abortions and potential complications are the same. About 98 percent of vacuum aspiration procedures occur without complications (Cates and Grimes, 1981; Laufe, 1977; Freedman et al., 1986). Vacuum aspiration results in 4 significantly fewer complications than D&C, including incidences of excessive blood loss, pelvic infection, cervical injury and uterine perforation (Cates and Grimes, 1981; Laufe, 1977; Freedman et al., 1986). A major study of 50,000 vacuum aspirations performed in the U.S. found that “incidence of excessive blood loss was 50 [percent] lower with vacuum aspiration than with sharp curettage (0.5 compared to 1.0 complications per 100 procedures)” (Tietze and Lewit, 1972). WHO now recommends MVA as the preferred method of uterine evacuation, suggesting that sharp curettage be used only if MVA is not available (WHO, 2000). (See Table 2 for data on the safety of MVA compared with sharp curettage.) Studies on the safety of vacuum aspirations have found extremely low complication rates. For example, safety data from 170,000 first-trimester EVA procedures performed at three U.S. outpatient clinics over a 16-year period found a rate of nine complications per 1,000 procedures, with only 0.7 complications per 1,000 procedures requiring hospitalization and no deaths (Hakim-Elahi et al, 1990). Similarly, a report on 12,888 MVA procedures occurring in 21 countries found an immediate complication rate of 0.8 per 100 procedures, and no deaths (Laufe, 1977). Specific data on the safety of MVA find few complications associated with the method. In general, MVA demonstrates the same level of safety as EVA, and greater safety than sharp curettage (Laufe, 1977; Freedman et al., 1986). (See Table 3.) A recent Vietnamese
study examined 210 first-trimester MVA abortions and included extensive follow up. Patients completed a daily symptom diary for seven days after the MVA, and were inter- BLE 2:fety Data for Vacuum Aspiration (VA) and viewed by a health care provider weekly for five weeks. No serious complications such as infection or heavy bleeding occurred among the study group (Do et al., 1998). MVA remains a safe procedure when practiced in the primary care setting. One doctor in independent family practice examined the complication rates of 1,677 MVA abortions performed in this setting. MVA was 99.5 percent effective, with a minor complication rate of 1.25 per 100 procedures; minor complications included infection (12 cases), retained products of conception (8 cases) and other complications not requiring hospitalization (1 case). These minor complications were easily treated, and there were no major complications or deaths among the procedures reviewed. The authors con ABLE 3:afety of Manual Vacuum piration (per 100 procedur clude that MVA may be safely and effectively provided in the primary office setting (Westfall et al., 1998).