HBV determines the most serious form of neonatal hepatitis. The earlier the infection occurs, the higher risk of chronically disease is.
Antepartum transmission is related to the infection degree of the mother: presence of viraemia (DNA-HBV) and HBeAg and has variable rates according to these markers.
Thus, the risk of antepartum transmission of HBV = Transplacental transmission may range from 8.9% to 33.3%, according to studies.
(Guo Z, Shi XH, Feng YL, et al. Risk factors of HBV intrauterine transmission among HBsAg ‐ positive pregnant women. Journal of viral hepatitis. 2013 May 1; 20 (5): 317-21).
(Farghaly AG, Hassan EM, Gawish S, Kotkat A. Vertical Transmission of HBsAg in Alexandria. The Journal of the Egyptian Public Health Association. 1989 DEC; 65 (3-4): 377-90).
(Zhu YY, Mao YZ, et al. Does hepatitis B virus prenatal transmission result in postnatal immunoprophylaxis failure?. Clinical and vaccine Immunology. 2010 Dec 1; 17 (12): 1836-41).
Transplacental transmission occurs more frequently in the case of premature births and is due to lesions at the level of chorial villosities or even viral infection of placental tissue.
In the case of maternal HBV infection in the 3rd trimester of pregnancy, the risk of infection in the newborn is greater than 80-90%;
In the case of maternal HBV infection in the 1st and 2nd trimester of pregnancy, the risk of infection in the newborn is less than 10%;
Intrapartum = perinatal transmission take place if the newborn is born naturally and is exposed during childbirth, through the skin and mucous membranes exposure, to the blood or other fluids of the mother infected with HBV.
According to a study conducted in China, which included 214 infants born from mothers with HBsAg positive the risk of transmitting the infection was 3.7% perinatal transmission.
(Shao ZJ, Zhang L, Xu JQ, et al. Mother ‐ to ‐ infant transmission of hepatitis B virus: a Chinese experience. Journal of Medical virology. 2011 May 1; 83 (5): 791-5).
Perinatal transmission continues to persist in Romania despite the program of immunization of newborns. The complete vaccination scheme is not always fully applied and in the cases indicated the association of immunoglobulin specific prophylaxis is not financially possible.
Postpartum – postnatal transmission is through breastfeeding and varies having a risk of 5 to 15% correlated with breastfeeding period.
The risk of maternal foetal transmission in the absence of vaccination is up to 90% and may vary depending on the presence or absence of HBeAg and viremia.
About Corneliu Zaharia
