PURPOSE: To provide information about main pregnancy outcomes in HIV-HCV coinfected women and about the possible interactions between HIV and HCV in this particular population. METHODS: Data from a multicenter observational study of pregnant women with HIV, conducted in Italian University and Hospital Clinics between 2001 and 2015, were used. Eligibility criteria for analysis were HCV coinfection and at least one detectable plasma HCV-RNA viral load measured during pregnancy. Qualitative variables were compared using the Chi-square or the Fisher test and quantitative variables using the Mann-Whitney U test. The Spearman's coefficient was used to evaluate correlations between quantitative variables. RESULTS: Among 105 women with positive HCV-RNA, median HCV viral load was substantially identical at the three trimesters (5.68, 5.45, and 5.86 log IU/ml, respectively), and 85.7 % of the women had at least one HCV-RNA value >5 log IU/ml. Rate of preterm delivery was 28.6 % with HCV-RNA 5log (p = 0.309). Compared to women with term delivery, women with preterm delivery had higher median HCV-RNA levels (third trimester: 6.00 vs. 5.62 log IU/ml, p = 0.037). Third trimester HIV-RNA levels were below 50 copies/ml in 47.7 % of the cases. No cases of vertical HIV transmission occurred. Rate of HCV transmission was 9.0 % and occurred only with HCV-RNA levels >5 log IU/ml. CONCLUSIONS: Coinfection with HIV and HCV has relevant consequences in pregnancy: HIV coinfection is associated with high HCV-RNA levels that might favour HCV transmission, and HCV infection might further increase the risk of preterm delivery in women with HIV. HCV/HIV coinfected women should be considered a population at high risk of adverse outcomes.