Objective To comprehensively evaluate the service capacity of maternal and child health care institutions in Jiangmen city, Guangdong province, over the years, and explore its main obstacle factors, so as to provide reference for optimizing maternal and child health care services.

Methods Indicators were selected from three dimensions: resource allocation, service quantity, and service quality. The entropy weight technique for order preference by similarity to ideal solution (TOPSIS) was used to evaluate the service capacity of maternal and child health care institutions in Jiangmen City from 2018 to 2023. The obstacle degree model was applied to identify the main influencing factors of service capacity.

Results The resource allocation index had been increased from 2018 to 2023, with average annual growth rates of 2.61% for actual beds, 2.69% for employees on duty, 3.72% for health technicians, and 10.89% for equipment worth over 10,000 yuan. However, the service quantities of outpatient and emergency visits, hospitalizations, and deliveries decreased, with average annual growth rates of − 2.83%, − 1.42%, and − 8.81%, respectively. Among various service quality indicators, the neonatal hospitalization mortality, rehospitalization rate and hospital-acquired infection rate are constantly improving, while other quality indicators fluctuated to varying degrees. The entropy weight TOPSIS method showed that the relative optimal service capacity was in 2023 (Ci = 0.607) and the relatively poor was in 2020 (Ci = 0.378). The results of obstacle degree model showed that the influence of neonatal hospitalization mortality and the total number of discharged patients was weakening year by year, while the influence of live births and the success rate of emergency critical rescue was gradually increasing.

Conclusion The overall service capacity of maternal and child health care institutions in Jiangmen city has been improving year by year, but there is still room for improvement. Attention should be paid to the impact of the decline in the number of live births and the success rate of emergency critical rescue on the service capacity of maternal and child health care.