Background: Mother to infant transmission of the hepatitis B virus (HBV) represents a major factor in maintaining chronic infection and depends on the degree of maternal infectivity status. Objectives: To determine the risk factors for maternal and perinatal Hepatitis B infection at ABUTH. To identify potential risk factors associated with HBV infection. To determine the infectivity status of carrier pregnant women in ABUTH. To determine the seroprevalence of HBV in babies delivered by HBV carrier pregnant women at ABUTH. To determine the relationship between infectivity status and trans-placental transmission. Research methods and Findings: A hospital-based descriptive cross-sectional study involving 240 consenting pregnant women who presented for delivery from 8th May to 20th July 2017 were tested for both HBsAg and hepatitis B envelope antigen using standard ELISA method. At delivery the cord blood was collected and tested for HBsAg and HBeAg respectively using standard ELISA method to determine the rate of transplacental infection. Structured proforma was used to obtain sociodemographics and other relevant data such as birthweight and APGAR scores. The results obtained were analysed using SPSS version 23. The seroprevalence of HBsAg among the parturient was (45/240) 18.8 % out of which 9.0% were positive for HBeAg. Twenty-three of the babies born to the HBsAg-positive mothers were positive for HBsAg, giving a neonatal sero-prevalence of 9.6% (23/240) and a vertical transmission rate of 51.1% (23/45). Four of the 23 babies positive for HBsAg were also positive for HBeAg, translating to 13.54% of the infected babies. The mean age was 29.2 +5.7 years, the highest HBV infection rate occurred in 30-34 years’ age group. Age and booking status were independent risk factors for HBV infection from the result obtained from this study.