fertility awareness based methods family planning review effectiveness, Billings ovulation method Creighton model symptothermal comparison, modern natural family planning typical use pregnancy rates, Pallone Bergus fertility awareness family medicine review, Standard Days Method TwoDay Method family planning, physician knowledge fertility awareness methods survey, NFP effectiveness industrialized nonindustrialized nations, cervical mucus basal body temperature family planning methods, family physician education natural family planning resources, fertility awareness methods versus rhythm method effectiveness
PMID 19264938 19264938 DOI 10.3122/jabfm.2009.02.080038 10.3122/jabfm.2009.02.080038
Keywords
Female, Fertility/physiology, Health Knowledge, Attitudes, Practice, Humans, Natural Family Planning Methods/methods, Pregnancy, Unplanned, United States