Background Adequate knowledge about the highest conception probability period in the reproductive cycle allows individuals and couples to attain or avoid their fertility probabilities. Poor knowledge of conception probability period leads to undesirable outcomes like unwanted pregnancy, miscarriage, and abortion. Determinants of knowledge of highest conception probability period were not well studied on economically disadvantaged countries. Therefore, our study aimed to identify individual and community level factors of knowledge of the highest conception probability period among women of reproductive age in low income African countries. Methods The appended and latest Demographic and Health Survey datasets of 15 low-income African countries was used for analysis. Model fitness was done using the Intraclass correlation coefficient, median odds ratio, and deviance. A model with the lowest deviance (model-III) was selected as the best model. Multilevel logistic regression model was used to identify determinant factors of knowledge of the highest conception probability period. In the final model, adjusted odds ratio with 95% confidence interval was reported and variables with p<0.05 were considered as statistically significant with knowledge of the highest conception probability period. Results Total weighted sample of 235,574 reproductive aged women with a median age of 27 years were included. The correct knowledge of the highest conception probability period among the study participants was 24.04% (95%CI = 23.87-24.22%). Maternal age groups ((20-24 (AOR = 1.49; 95%CI = 1.44-1.55), 25-29 (AOR = 1.62; 1.56-1.68), 35-39 (AOR = 1.76; 1.68-1.84), 40-44 (AOR = 1.75; 1.67-1.83), and 45-49 (AOR = 1.83; 1.74-1.93)), marital status((currently in union (AOR = 1.75; 1.16; 1.13-1.20), formerly in union (AOR = 1.75; 1.11; 1.06-1.16)), better educational status ((secondary (AOR = 2.08; 2.01-2.14) and higher(AOR = 3.36; 3.18-3.55)), higher wealth index ((middle (AOR = 1.08; 1.04-1.12), richer (AOR = 1.24; 1.20-1.28), and richest (AOR = 1.51; 1.45-1.57)), knowledge of contraceptive methods (AOR = 2.63; 2.49-2.77), current contraceptive use (AOR = 1.14; 1.11- 1.16), and urban residency (AOR = 1.26; 1.21-1.29) were statistically significant with knowledge of the highest conception probability period. Conclusion In this study, knowledge of the highest conception probability period among women of reproductive age in low-income African countries was low. Therefore, improving the fertility awareness through comprehensive reproductive education or counseling could be one of the operational ways to control unintended pregnancy.
