September 7, 2005
Many hepatitis C virus (HCV)-infected infants were infected in utero, according to researchers who investigated when mother-to-child HCV-infection occurs and evaluated associated transmission factors. The prospective cohort study, conducted by J. Mok of University College London and colleagues, included 54 HCV-infected children assessed within three days of birth for HCV RNA polymerase chain reaction (PCR) results.
Of the HCV-infected children, 17 (31 percent) tested PCR positive in the first three days of life and could be assumed to have acquired HCV in utero. Testing positive was not associated with sex (53 percent female vs. 49 percent male, p=0.77) or type of delivery (29 percent elective caesarian section in both groups, p=0.98). Evidence of intrauterine infection was significantly associated with lower birth weight and HCV genotype 1 (58 percent vs. 12 percent, p=0.01).
While a higher proportion of infants testing PCR positive within the first three days of life were born to HCV/HIV co-infected mothers, the association did not reach statistical significance. Excluding such infants did not affect other findings.
Thirty-seven of the HCV-infected children (68 percent) were PCR negative in the first three days of life. Of them, 27 tested PCR positive when tested again at three months, and nine were first positive after three months (one child had no more tests).
"These results suggest that at least one-third and up to half of infected children acquired infection in utero," concluded the researchers. "Although postpartum transmission cannot be excluded, these data suggest that it is rare. The role of HCV genotypes in the timing and mechanism should be explored further."
The full report, "When Does Mother to Child Transmission of Hepatitis C Virus Occur?" was published in Archives of Disease in Childhood Fetal and Neonatal Edition (2005;90(2):156-160).