Abstract
PURPOSE: Accurate knowledge of the fertile window-the period within the ovulatory cycle when conception is most likely-is important to reproductive health and informed family planning. Prior research has consistently documented low to moderate awareness of this concept, particularly among young adults. This study examined sociodemographic and reproductive variables associated with fertile window knowledge among individuals of reproductive age in Colombia and Ecuador. METHODS: Data were drawn from a cross-sectional analysis within the ongoing international "FERTIPLAN" project, which investigates fertility intentions in Latin America. The sample comprises 1456 participants (73.4% women, 26.6% men) aged 18-44 years from Colombia and Ecuador. RESULTS: Women were nearly twice as likely as men to demonstrate knowledge of the fertile window (odds ratio [OR] = 1.98; 95% confidence interval [CI]: 1.32-2.97). All age groups aged 25 years and older exhibited significantly higher odds of fertile window knowledge compared with the 18-24 age group (ORs ranging from 1.89 to 2.45), but no significant differences were observed among the older age groups, indicating that the primary knowledge gap lies between the youngest cohort and all older age groups. Participants with higher income (OR = 2.59; 95% CI: 1.54-4.35), fertility intentions (OR = 1.47; 95% CI: 1.06-2.04), and familiarity with fertility awareness-based methods (OR = 2.55; 95% CI: 1.58-4.12) had significantly greater knowledge of the fertile window. CONCLUSIONS: These findings underscore the influence of sex, age cohort, socioeconomic status, and reproductive factors on fertility awareness, offering valuable insights for advancing preconception care and addressing knowledge gaps in Latin America.