BACKGROUND: In 2016, the World Health Organization (WHO) updated its antenatal care (ANC) guidelines to improve the quality and effectiveness of ANC services. Whether in Tanzania the services are utilized according to the WHO's guidelines remains a subject for investigation. Thus, the aim of this study was to assess the utilization of ANC services in line with the antenatal care guidelines among postnatal women in Dodoma City, Tanzania. METHODS: We employed an analytical cross-sectional study design. A questionnaire was developed based on information from literature and the Tanzania ANC guideline of 2018 to obtain data about social demographic characteristics and ANC services utilization. A total of 426 postnatal women were sampled using a proportionate systematic random sampling procedure. Data were collected using a face-to-face interview and abstraction from the ANC card. Using SPSS software version 26, We performed descriptive and regression analyses using SPSS software version 26 to determine the utilization of services and the associated factors. Data were considered significant at a p-value <
0.05 and reported along with 96% confidence intervals. RESULTS: The majority of the postnatal women (63.2%) initiated ANC visits during their first trimester. The availability of ANC support person was the key factor associated with the early initiation of ANC services. The median number of antenatal contacts was 4, with only 6.8% of postnatal women being able to meet the minimum of eight contacts as recommended by WHO. The top ANC services provided to the majority of women include education about the use of bed nets to prevent malaria during pregnancy (92.9%), Tetanus Toxoid (TT) vaccination (86.8%), Intermittent Preventive Therapy for malaria (IPTp-SP) medication (90.8%) and mebendazole medication to treat or prevent parasitic infections (90.1%). CONCLUSION: Overall, the majority of women in Dodoma initiate ANC contacts within the first trimester, but only a small proportion complete eight contacts as recommended by WHO. The health care system should prioritize addressing the factors identified in this study, particularly by encouraging ANC support persons to increase the frequency of ANC contacts.