Maternal care in Nairobi slums is characterized by high rates of morbidity and mortality due to preventable conditions such as anaemia and malnutrition. A quasi-experimental design was employed, with baseline data collected from 500 participants. A cluster-randomized trial approach was used to allocate participants into intervention and control groups. An average of 82% adherence rate to programme activities was observed across both genders in the intervention group compared to 63% in the control group, indicating a significant improvement (p < 0.05). The mobile phone-based health education programme significantly improved maternal care knowledge and practices among mothers living in Nairobi slums. Further research is recommended to explore long-term sustainability of these programmes and their scalability across different settings. Treatment effect was estimated with $\text{logit}(p_i)=\beta_0+\beta^\top X_i$, and uncertainty reported using confidence-interval based inference.