Maternal care facilities in Nigeria are crucial for newborn health outcomes. A systematic review was conducted to assess the methodological rigor of studies evaluating maternal care facilities in Nigeria. Quasi-experimental designs were used to measure clinical outcomes. The analysis revealed that 65% of reviewed quasi-experimental designs utilised appropriate control groups, indicating a significant improvement over previous methods. While the majority of studies employed robust quasi-experimental designs, there is still room for enhancing data quality and consistency across different regions in Nigeria. Future research should prioritise standardising protocols and increasing sample sizes to ensure more reliable outcomes measurements. Maternal care facilities, Quasi-experimental design, Clinical outcomes, Systematic review Treatment effect was estimated with $\text{logit}(p_i)=\beta_0+\beta^\top X_i$, and uncertainty reported using confidence-interval based inference.