Abstract
<title>Abstract</title> <p>Background While antenatal care (ANC) coverage has improved substantially in many low- and middle-income countries (LMICs), increasing evidence suggests that attendance alone does not guarantee receipt of the full package of recommended maternal health interventions. Group Antenatal Care (G-ANC) has emerged as a promising model for improving maternal health service utilization and quality of care. However, little is known about how implementation performance varies across facilities when G-ANC is integrated into routine government health systems. This study assessed facility-level variation in the delivery of essential ANC interventions among women enrolled in a routine G-ANC program in Geita Region, Tanzania. Methods We conducted a secondary analysis of routinely collected implementation data from the Mlinde Mama Project between January 2023 and August 2024. The study included 5,936 pregnant women enrolled in G-ANC across six public health facilities comprising two dispensaries, two health centres, and two district hospitals. Twelve facility-level ANC indicators was assessed, including ANC4+, intermittent preventive treatment for malaria in pregnancy (IPTp3+), iron–folate supplementation, haemoglobin testing, malaria testing, HIV testing, syphilis testing, deworming, facility delivery, blood pressure (BP) monitoring, tetanus vaccination and urine testing. A composite facility performance score was calculated for nine of these twelve indicators, as the mean coverage across the nine indicators. Results Coverage of ANC4 + visits (90.2–95.0%), facility delivery (94.1–97.7%), malaria testing (91.5–95.5%), and blood pressure monitoring (100% across all facilities) remained consistently high. In contrast, substantial variation was observed in preventive and diagnostic interventions. IPTp3 + coverage ranged from 60.1% to 86.3%, iron–folate supplementation from 75.0% to 92.7%, HIV and syphilis testing from 59.9% to 95.0%, and urine testing from 30.1% to 62.7%. Composite facility performance scores ranged from 80.1% to 91.9%, with Bwanga Health Centre ranking highest and Butengorumasa Dispensary lowest. Health centres demonstrated the strongest overall implementation performance across most ANC indicators, with variations observed across the six facilities for the nine selected essential ANC indicators. Conclusions Among women enrolled in G-ANC across six public facilities, ANC attendance and facility delivery coverage were consistently high. However, substantial variation in the delivery of essential preventive and diagnostic ANC interventions persisted across facilities, highlighting important gaps between service utilization and effective coverage. Routine maternal health monitoring should move beyond attendance indicators alone to include measures of ANC content and implementation quality. Strengthening facility-level implementation capacity, supportive supervision, and continuous quality improvement will be essential to ensure that increased ANC attendance translates into comprehensive, high-quality maternal healthcare.</p>