Prevention of vertical transmission of hepatitis B: An evaluation of adherence rates and risk factors for failure to provide immunoprophylaxis therapy in a single Australian centre.

Abstract

Background and Aims: Immune prophylaxis therapy (IPT) is well established in decreasing perinatal transmission of hepatitis B virus (HBV) and is a key strategy to reduce the prevalence of chronic hepatitis B (CHB) worldwide. Universal guidelines recommend administration of HBV immunoglobulin (HBIg) and HBV vaccine within 12 hours of birth. Immunisation adherence rates and risk factors for failure to provide timely IPT to babies born to CHB mothers remain poorly defined. We conducted a retrospective cohort study to determine compliance with IPT guidelines in routine obstetric practice at Monash Health, Australia. Method(s): 451 mothers with CHB delivered 451 live born infants at Monash Health between 2008 and 2013. There were 3 stillbirths and 3 sets of twin livebirths. Demographic and disease data, referral rates for specialist HBV care, neonatal and maternal morbidity outcomes and timing of HBIg and HBV vaccine administration were extracted from hospital records. Multivariate logistic regression analysis was utilized to identify the risk factors associated with failure to provide timely administration of IPT. Result(s): 47.23% of CHB mothers were diagnosed on routine antenatal screening. Mean maternal age was 30.37+/-5.25 years and mean gestational age was 38.99+/-2.50 weeks. 55.67% of women received antenatal specialist care for CHB and 4.29% commenced prophylactic antiviral therapy in the third trimester. 79.82% of newborns received HBIg within 12 hours and 8 babies received no HBIg prior to discharge (1 due to withdrawal of parental consent). 97.12% of newborns received HBV vaccine within 12 hours and 1 baby received no HBV vaccination prior to discharge. On multivariate analysis, antenatal care provided by an Obstetrician and or a Specialist for CHB was associated with timely administration of HBIg (OR 1.64, p = 0.038, CI:1.03-2.61). The requirement for an interpreter at birth, maternal age and parity, post-partum complications, gestational age and neonatal morbidity were not significantly related to delayed administration of HBIg. There were no predictors for timely HBV vaccine. Conclusion(s): The efficacy of IPT in the prevention of HBV vertical transmission has been well documented. However, the adherence rate to these recommendations remains sub-optimal especially for timely HBIg administration in routine obstetric practice. Targeted clinical interventions to improve HBIg adherence rates and serologic follow-up of infants born to CHB mothers is recommended.