Application of machine learning to predict delayed fecundability among women in sub-Saharan Africa.

Abstract: Delayed fecundability, defined as trying to conceive for ≥12 months without success, is a growing global concern due to the threat of fertility rates falling below the replacement level. This study aimed to predict delayed fecundability and identify influential predictors. Secondary data from recent Performance Monitoring for Action (PMA) surveys on fertility, contraception, and reproductive health in five sub-Saharan African countries were used. Preprocessing and feature engineering included imputation, encoding, and correlation filtering. Feature selection was done using the Boruta algorithm. Machine learning models, including random forest, XGBoost, and LightGBM, were developed and optimized via grid search with cross-validation. Models were compared using default hyperparameters. Interpretability was enhanced through SHapley Additive exPlanations (SHAP) plots, and heterogeneity was explored with subgroup SHAP analysis to identify context-specific predictor effects. Delayed fecundability was present in 31.01% of women. Grid search optimization improved model performance, with random forest achieving the highest accuracy (79.2%) and AUC (0.94). SHAP analysis identified key predictors, including age 36-49 (0.211), being married (0.208), ovulation-inducing treatment (0.173), and herbal remedy use (0.118). Subgroup SHAP analysis revealed heterogeneity: younger age reduced risk in 15-25-year-olds, fertility treatment history was the main risk driver in treated women, and marital status and childbirth had variable effects across subgroups. The random forest model best predicted delayed fecundability, with age, marital status, and treatment history as key predictors. Subgroup SHAP analysis revealed risk patterns across populations. Targeted screening and tailored fertility counseling, especially for couples with prior fertility treatments, are recommended to support timely conception. Lay summary: Many women struggle to get pregnant even after trying for a year or more, a condition called delayed fecundability. This issue is becoming more common worldwide and can signal problems with fertility. We used data from surveys in five African countries to find out which factors may predict this delay. Using computer models that can learn from data, we found that age, marital status, and past use of fertility treatments were strong predictors. Our best model correctly identified nearly 80% of women with delayed fecundability. To make the findings easy to understand, we used a method that explains how each factor influences the result. We also found that the effects of these factors vary by age and treatment history. Our results can help health workers identify women at higher risk earlier, especially in places where fertility services are limited, and provide them with better, more personalized care.