Techniques for the interruption of tubal patency for female sterilization
Compared with tubal ring and other methods, electrocoagulation was associated with less morbidity. However, the risk of burns to the small bowel might be a serious criticism of the approach. Aspects such as training, costs and maintenance of the equipment may be important factors in deciding which method to choose.
RHL Commentary by Mittal S
1. EVIDENCE SUMMARY
The review compares various techniques of tubal interruption, such as tubal rings, clips, electrocoagulation and the modified Pomeroy method for female sterilization. Nine randomized controlled trials conducted between 1976 and 1991 have been included. Clips were compared with tubal rings (three trials) and with the Pomeroy method (one trial). Electrocoagulation was compared with the Pomeroy method (two trials) and with tubal rings (two trials). In one trial, Filshie clips was compared with Hulka-Clemens clips.
Ring versus clips
There were no reported cases of operation-related mortality in any of the included studies. Major morbidity and method failure are rare with all current method of female sterilization. Minor morbidity and technical failures (failure to accomplish tubal occlusion with the intended method) were more likely to occur with tubal ring rather than with clips (Peto odds ratio [OR]: 2.15; 95% confidence interval [CI] 1.22-3.78). However, there was no statistical or clinical difference in pregnancy rate between these two methods.
Pomeroy versus electrocoagulation
Major morbidity (two studies, 2127 women, Peto OR 2.87; 95% CI 1.13-7.25) and postoperative pain (two studies, 2127 women Peto OR 3.85; 95 % CI 2.91-5.10) were more frequent in the Pomeroy group compared with the electrocoagulation group. However, there was one case of bowel burn following electrocoagulation-an issue that cannot be overlooked in the case of electrocoagulation.
Ring versus electrocoagulation
Minor morbidity, technical failures and procedural difficulties were similar following tubal ring or electrocoagulation, though more women had postoperative pain following sterilization with tubal ring than electrocoagulation (Peto OR 3.28; 95% CI 2.31-4.66).
Pomeroy versus clips
The modified Pomeroy method did not differ from clips in terms of minor morbidities and menstrual irregularities. There were no discernible differences between the effectiveness of Filshie or Hulka-Clemens clips.
The authors searched the literature appropriately using the search strategy of the Cochrane Fertility Regulation Review Group to identify all randomized trials comparing various techniques of interruption of tubal patency for female sterilization. The inclusion criteria used in the review were appropriate.
Most of the trials included in the review were small and there were only one or two trials available for most comparisons, limiting the statistical strength of the findings. Over the years Filshie clip has evolved from mark I to mark VI with differing failure rates; the review does not specify the marks of the Filshie clip used in the trials.
The authors have rightly noted that in the trials that compared major morbidity, the number of subjects was too small to reach any reliable conclusions. The Cochrane review methodology required the inclusion of only randomized controlled trials. Nevertheless, the review discusses results from a prospective observational study of long-term pregnancy risk associated with female sterilization that provides useful information about failure rates of different methods (1).
2. RELEVANCE TO UNDER-RESOURCED SETTINGS
2.1. Magnitude of the problem
Tubal sterilization is one of the most popular contraceptive choices in the majority of developing countries (2). Through the years, the Indian National Family Welfare Programme has focused primarily on sterilization as a method of contraception, both in terms of programme targets and performance evaluation. The percentage of eligible couples protected by sterilization has steadily increased from 1.6% in 1965-1966 to 30.1% in 1989-1990 and has remained around that level for over a decade (29.1% in 1998-1999) (3). As a result of a steady rise in the total number of eligible couples, the total number of sterilizations performed in India is gradually increasing (3.87 million in 1996-1997 versus 4.67 million in 2000-2001) (4).
In 1992, WHO estimated that over 100 million women of childbearing age had been sterilized globally and that more than 100 million women in the developing world would seek sterilization in the next 20 years (5). Minilaparotomy with the Pomeroy method remains the main approach for tubal sterilization in many developing countries. Its ease of use and health-care workers wide familiarity with it have contributed to the popularity of this method. However, in big cities in India, large hospitals and camp settings, and wherever trained gynecologists are available the laparoscopic approach involving application of rings is frequently used because of its simplicity, safety, speed and shorter postoperative hospital stay. Electrocoagulation of tubes is not a popular method as it requires more sophisticated instruments, uninterrupted electricity supply and greater skill on the part of the operator to perform the operation safely.
2.2. Applicability of the results
The results of this review are completely applicable to under-resourced settings. In applying the findings of this review health care services will have to consider first the pros and cons of the method of abdominal entry for tubal occlusion. In many under-resourced settings minilaparotomy and the Pomeroy technique can be readily used. If facilities and trained personnel are available laparoscopy and bipolar electrocoagulation could be applied.
2.3. Implementation of intervention
Minilaparotomy and the Pomeroy technique can be implemented relatively easily if there are facilities for surgical procedures. The use of laparoscopy and electrocoagulation have more resource implications. There is also need for training before the technique can be effectively implemented.
3. RESEARCH
It will be useful to have a study that evaluates the safety, technical failures, subsequent pregnancies and morbidity associated with female sterilizations performed outside of hospitals (i.e. field settings). Research is also required to evaluate in large multicentre randomized trials the comparative advantages and disadvantages of newer techniques of tubal sterilization such as blockage of proximal end with chemicals, cauterization and plugs.
References
- Peterson HB, Xia Z, Hughes JM, Wilcox LS, Taylor LR, Trussell J. for the US clollaborative review of sterilization working group. The risk of pregnancy after tubal sterilization: Findings from the US collaborative review of sterilization. American journal of obstetrics and gynecology 1996;174:1161-1170.
- United Nations Population Division, Department of Economic and Social Affairs. Levels and trends of contraceptive use as assessed in 1998. Web site: http://www.un.org/esa/population/pubsarchive/wcu/fwcu.htm (accessed on 15 January 2004).
- Central Statistical Organization. Percentage of couples currently practicing family planning methods. New Delhi, Ministry of Statistics and Programme Implementation, India. p53:2000.
- Government of India. Annual report. New Delhi, Ministry of Health Family Welfare, 2002.
- Female sterilization: a guide to provision of services. Geneva, World Health Organization 1992.
This document should be cited as: Mittal S. Techniques for the interruption of tubal patency for female sterilization: RHL commentary (last revised: 21 June 2003). The WHO Reproductive Health Library; Geneva: World Health Organization.