A new literature review, conducted with support from USAID, suggests that the levonorgestrel (LNG) contraceptive implant has slightly less effect on a woman's menstrual cycle than the injectable contraceptive, DMPA. This study provides useful information for women who want to use a long-lasting family-planning method but are wary of the menstrual changes that hormonal contraceptives cause.

Scientists from Family Health International reviewed the literature and found 16 published studies in which the menstrual diaries of about 1,600 DMPA users and 2,300 implant users from around the world were analysed. The reviewers concluded that women who used the LNG implant were slightly more likely to have uninterrupted cycles than were women who used DMPA. After one year, 23 per cent of women using implants and 11 per cent of women using DMPA recorded normal menstrual patterns.

Without standardised reporting, providing evidence-based comparisons of contraceptive regimens is difficult. More studies comparing hormonal methods could help women make informed choices about which methods would suit their needs best.

Source: FHI/Hubacher D, Lopez L, Steiner MJ, Dorflinger L. Menstrual pattern changes from levonorgestrel subdermal implants and DMPA: systematic review and evidence-based comparisons. Contraception 2009;80(2):113-8.

Failure of some vasectomy techniques

A medical researcher at Family Health International is the lead author of a review - prepared with support from USAID - that emphasises the importance of generating more data about which vasectomy techniques are most effective. The conclusions are important for programmes seeking to promote this underused family-planning method.

The review of published data about commonly used techniques found surprisingly little high-quality evidence about the long-term success of the various methods. The most common method of vasectomy used in developing countries is simple ligation and excision, in which a surgeon closes off the vas deferens (the duct that transports sperm) with sutures and then removes about a centimetre of it.

However, some of these vasectomies become ineffective when new connections grow between the ends of the blocked vas, allowing for the passage of sperm. A study published in 2003-conducted in Nepal and led by FHI researchers with USAID support showed an annual pregnancy rate associated with this type of vasectomy of about one per cent.

In the United States and other high-resource settings, surgeons typically use a combination of vasectomy techniques. In addition to sutures, they may cauterise the vas, or create a tissue barrier between the severed ends. Vasectomies performed using at least two of these techniques, especially cautery plus the use of a tissue barrier, are most likely to succeed.

Source: FHI/Sokal DC, Labrecque M. Effectiveness of vasectomy techniques. Urology Clinic of North America 2009;36(3):317-29.