Mother-to-child transmission (MTCT) is the major source of HIV infection among children under the age of 15 years. There were limited studies on the MTCT rate in Amhara Region, Ethiopia. Therefore, this study aimed to measure mother-to-child transmission and to identify factors asso- ciated with MTCT. An institutional-based retrospective cohort study was conducted among HIV-exposed infants (HEIs). The HEIs who booked in mother–baby pair cohort register between January 2014 and December 2016 were abstracted and included in the study. A structured pretested questionnaire was used for data abstraction. The collected data were coded and double entered into EPI Info version 3.5.4 and exported to STATA version 14 for analysis. A penalized logistic regression model was used. p-value <0.05 was taken as the significance level. A total of 796 HEIs participated in the study in which 96.9% received nevirapine prophylaxis, 97.5% were exclusively breastfed for 6 months, and 95.2% received HIV test at 6 weeks. About 36.5% of mothers of HEIs received ART (Antiretroviral Treatment) for less than 4 weeks during delivery. Of the mothers of HEIs, 7.6% were in WHO clinical stage I and 64.1% had >350 CD4 count at the first antenatal care visit. Overall, MTCT of HIV was 1.5%, and 59.2% of HEIs were discharged from the PMTCT care at the age of 12-18 months. The vertical transmission of HIV was significantly associated with the duration of ART (AOR 0.16; 95% CI: 0.02, 0.96). The MTCT was 84.0% less likely in mothers who did receive Antiretrovirals (ARVs) >12 months compared with mothers who did receive ARVs <4 weeks during delivery. The study indicated that vertical transmission of HIV was significantly associated with the duration of ART. Even if a considerable low MTCT rate was observed, early identification and treatment among HIV-positive pregnant women should be strengthened.
