[Natural Family Planning methods and Barrier: CNGOF Contraception Guidelines].

Objective: To develop clinical practice recommendations for the use of natural contraception and female and male barrier methods.

Materials And Methods: A systematic review of English and French literatures related to the safety and effectiveness of natural contraceptive methods based on PubMed, Cochrane Library, practice recommendations issued by international scientific societies and guidelines provided by the World Health Organization (WHO) as well as updates from the Center for Disease Control and Prevention (CDC).

Results: Natural contraceptives methods include fertility awareness-based methods, lactational amenorrhea method (LAM) and withdrawal method. The prevalence is low (4.6% of users) and remains stable over the years. Identification of the fertile period can be symptom-based cervical mucus (Billings), two-day method, basal body temperature, symptom-thermal method or based on calendar calculation (Ogino-Knauss, standard day method). Pregnancy rate after one-year utilization varies from 0.4% to 5% in perfect use but 8% in common practice. Effectiveness increases with absence of vaginal sex and decreases when combined to barriers method inadequately implemented. Data is scarce on reliability and effectiveness of ovulation predictor kits readily available on internet. Lactational amenorrhea method (LAM) can be very effective (98%) provided three conditions are fulfilled: within 6 months after birth, amenorrhea is effective, and breastfeeding is exclusive or quasi exclusive (day/night). Withdrawal method is constraining and of limited effectiveness. Male and female condom, diaphragm, cervical cap and spermicides are mechanical and chemical barrier methods, preventing spermatozoids from passing through the cervix into the uterus and therefore preventing fecundation. Female and male condoms offer a double protection to avoid pregnancy and prevent STD's. They are effective provided strict conditions of use are fulfilled. Male condom is favored by teenagers (45.6% among 15 to 19 years old), sometimes in combination with contraceptive pill (16% of cases). Women on the pill decreases according to their age. Pregnancy rates within the first year of consistent and correct use of these methods vary between 5 to 26% and reach 20 to 32% in practical use. Diaphragm and cervical cap need to be used in combination with spermicides. Spermicides have limited effectiveness when used alone.

Conclusion: In common practice, natural and barrier contraceptive methods are more constraining and less effective than modern contraceptive method. They can be an alternative at given time and/or in situations where the women or the couple accept the possibility of an unexpected pregnancy which might be terminated or not. Women/couples need to be properly informed on how to use such methods, on their disadvantages and possible failures in common practice. Reminders are to be given on emergency contraceptive methods (IUD, hormonal) after unprotected sex.