Epidemiology

Mother to child HCV transmission often occurs in utero

Last Updated: 2005-03-11 15:55:43 -0400 (Reuters Health)

By Anthony J. Brown, MD

NEW YORK (Reuters Health) - In up to one half of cases, mother to child transmission of hepatitis C virus (HCV) occurs in utero, according to UK researchers. In the remaining cases, infection seems to occur during delivery with little evidence of postpartum transmission.

"Knowing when mother to child transmission of HCV occurs is important for developing strategies to prevent the problem," investigator Dr. L. Pembrey, from University College London, told Reuters Health.

The study involved 54 vertically exposed children with HCV infection who had had an HCV PCR test performed in the first 3 days of life. The researchers' findings appear in the March issue of the Archives of Disease in Childhood: Fetal and Neonatal Edition.

Seventeen subjects (31%) had a positive PCR test in the first 3 days of life, suggesting that HCV transmission occurred in utero. Twenty-seven children (50%) first tested positively at 3 months, indicating that transmission either occurred late in pregnancy or during delivery. The timing of transmission for the remaining nine children was unclear, but did not seem to occur postpartum through breast-feeding.

Mode of delivery and infant gender were not associated with PCR positivity in the first 3 days of life. By contrast, lower birth weight and infection with genotype 1 were linked to early positivity.

The researchers note that maternal treatment using interferon alpha and ribavirin to lower viral load and thus the risk of vertical transmission is not possible. These agents are contraindicated during pregnancy.

Should effective treatment become available, they add, "it would need to be initiated early in pregnancy" because of the high rate of in utero transmission.

Arch Dis Child 2005;90:F156-F160.