@TostadaEnPolvo si, en el hilo hay un tuit al respecto si te fijas. No obstante es bastante controvertida y de baja calidad en general, acá una revisión vieja de cochrane: https://t.co/ZwW2GdqnDx

From my cursory review of the literature there is (unsurprisingly) little level 1 evidence for any type of rhythm/etc birth control. https://t.co/0HqaasXtE5

.@notmuchelse Fertility awareness-based methods are unpopular and, for most couples, relatively ineffective: http://t.co/NZjNhMVqJC