JHPIEGO TrainerNews™ |
Clinical Update: Contraceptive Pearl
(April 2002)
Improved Vasectomy?
Question: I have heard there is a new more effective technique for vasectomy that has something to do with fascia. What is the technique and what is "fascia" anyway?
Answer: Fascia is fibrous connective tissue found in many parts of the body, whose basic function is to give structural support. (Some runners develop an inflammation of the fascia at the flat part of the foot called "plantar fasciitis.")
Vasectomy is highly effective, but has some failures related to "recanalization" or new connections formed between the severed/tied ends of the vas. To try to improve vasectomy effectiveness, "fascial interposition" has been developed in which the fascia normally covering the vas is pulled over one severed vas end and sewn shut, thus increasing the barrier for any sperm to traverse. In a study sponsored by Family Health International and EngenderHealth, about 93% of men with the procedure reached a low sperm count at 22 weeks post-procedure compared to 81% of men without the fascial interposition. Whether pregnancy would be reduced remains to be seen.
Reference: Best K. Contraceptive update: Technique modification may improve vasectomy effectiveness. Network 2002; 21:26-27.
OCs and Cervical Cancer
Question: Is there some new evidence linking cervical cancer with OCs? What are the implications?
Answer: Yes there is new evidence, but the World Health Organization (WHO) is not currently recommending change in OC use. A new analysis from 8 studies conducted by IARC (the International Agency for Research on Cancer) recently found an increased risk of cervical cancer, but only for women who were both:
- Currently positive for Human Papilloma Virus (approximately 13% of
women) and;- Long-term OC users (use 5 years or more).
WHO Review
The issue of whether OCs might increase cervical cancer risk is a longstanding one. Earlier studies have found a modest association with long term OC use (1.3-to 1.8-fold) but it was unclear if this was a biological relationship or due to lifestyle differences of OC users. The IARC study and other studies were reviewed by a WHO expert group in March 2002.
Increased risk likely with long term use
The WHO concluded: "Although alternative explanations for these findings remain possible, it appears increasingly likely that long-term use of combined oral contraceptives by women with persistent HPV infection is a contributing factor in the development of cervical cancer. This increased risk is currently thought to be up to 2-fold after long-term use (five years or more)."
No change in practice now
Taking this information into account, however, and weighing the various risks and benefits, WHO does not currently recommend any change in OC practice or use. "Pending the results of new studies in progress, the experts present at the 11 March 2002 meeting recommended no changes in oral contraceptive prescribing practice or use.... All methods of contraception, including oral contraceptives, carry risks
and benefits. For young, healthy, non-smoking women, the health benefits of oral contraceptive use (including a reduced risk of endometrial and ovarian cancers) far exceed the health risks."
The full text of the statement can be found at the WHO website:
http://www.who.int/reproductive-health/cancers/cacx-ocs.en.html
Births and Cervical Cancer
Question: I heard recently that the more children a woman has, the greater her risk of cervical cancer. Is that true?
Answer: Yes. A number of studies over the years have found a strong relationship of parity with squamous-cell cervical cancer, but a large new study from IARC (the International Agency for Research on Cancer) among women who were HPV (Human Papilloma Virus)-positive, found fairly definitive evidence. Compared to nulliparous women, those with 3 or 4 full-term pregnancies had 2.55 times the risk, and those with 7 or more births had 3.82 times the risk.
The mechanism appears to be related to the mechanics and stress of childbirth such as stretching and tearing of the cervix. Neither delivery by C-section nor abortions were associated with increased risk.Reference: Munoz et al. Role of parity and human papillomavirus in cervical cancer: the IARC multicentric case-control study. Lancet 2002; 359:1093-1101.
These "Pearls" were prepared by Dr. James D. Shelton, Senior Medical Scientist, Office of Population, United States Agency for International Development (USAID).