There is evidence of deterioration of hepatitis C after pregnancy. To investigate potential histological changes, we compared liver biopsy samples taken before and after delivery from 12 women positive for hepatitis C virus (HCV) and 12 nonpregnant HCV-positive women. Semiquantitative histopathological measurements showed greater deterioration in cases than in controls (necroinflammatory score deterioration 83.3% vs 25.0%; fibrosis score 41.6% vs 8.3%). This case-control study suggests that pregnancy may worsen HCV-related histopathological injury.