This study finds:

• HIV/HCV coinfected women were twice as likely to transmit HCV (9.2% 136/1474) as women infected only with HCV
• Multivariate analysis did not find any significant effect on increase in transmission by breastfeeding or mode of delivery, BUT—
• Coinfected women using caesarean section were 60% less likely to have infected baby than when using vaginal delivery
• babies who were breastfed were 4 times more likely to be infected with HCV
  
  BJOG 2001 Apr;108(4):371-7

OBJECTIVE:
To investigate the effects of mode of delivery and infant feeding on the risk of mother-to-child transmission of hepatitis C virus.

DESIGN:
Pooled retrospective analysis of prospectively collected data.

SAMPLE:
Data on hepatitis C virus seropositive mothers and their children identified around delivery were sent from 24 centres of the European Paediatric Hepatitis C Virus Network.

MAIN OUTCOME MEASURES:
Hepatitis C virus infection status of children born to hepatitis C virus infected women.

RESULTS:
A total of 1,474 hepatitis C virus infected women were identified, of whom 503 (35%) were co-infected with HIV. Co-infected women were more than twice as likely to transmit hepatitis C virus to their children than women with hepatitis C virus infection alone. Overall 9.2% (136/1,474) of children were hepatitis C virus infected. Among the women with hepatitis C virus infection-only, multivariate analyses did not show a significant effect of mode of delivery and breastfeeding: caesarean section vs vaginal delivery OR = 1.17, P = 0.66; breastfed versus non-breastfed OR = 1.07, P = 0.83. However, HIV co-infected women delivered by caesarean section were 60% less likely to have an infected child than those delivered vaginally (OR = 0.36, P = 0.01) and those who breastfed were about four times more likely to infect their children than those who did not (OR = 6.41, P = 0.03). HIV infected children were three to four times more likely also to be hepatitis C virus infected than children without HIV infection (crude OR = 3.76, 95% CI 1.89-7.41).

CONCLUSIONS:
These results do not support a recommendation of elective caesarean section or avoidance of breastfeeding for women with hepatitis C virus infection only, but the case for HIV infected women undergoing caesarean section delivery and avoiding breastfeeding is strengthened if they are also hepatitis C virus infected.