Sperm human papillomavirus infection and risk of idiopathic recurrent pregnancy loss: insights from a multicenter case–control study

Abstract

To test the hypothesis claiming an association between human papilloma virus (HPV) sperm infection and idiopathic recurrent pregnancy loss (RPL). Multicenter retrospective case-control study. Three university hospitals. Cases included men belonging to couples affected by first trimester idiopathic RPL. Controls included men belonging to couples with proven fertility and no history of pregnancy loss; RPL was defined as the previous loss of 2 or more pregnancies. Couples were defined as "fertile" if they achieved a full-term pregnancy within the year before enrollment in the study. All participants conceived without assistance. The association between HPV DNA sperm infection, as identified using polymerase chain reaction, and RPL. The HPV DNA sperm infection was detected in 23 of 117 cases (20%; 95% confidence interval [CI]: 13%, 28%) and in 3 of 84 controls (4%; 95% CI; 1%, 10%) (P<.001). A comparison across baseline characteristics and multiple regression analysis did not identify any potentially confounding factors. Multivariate regression models showed a significant association between HPV DNA sperm infection and RPL (adjusted odds ratio, 7.44; 95% CI: 2.08, 26.58; P=.002 [Model 1]; adjusted odds ratio, 8.96; 95% CI: 2.41, 33.44; P=.001 [Model 2]). The prevalence of HPV sperm infection was significantly higher in couples affected by RPL than in their fertile counterparts. Notably, the semen sample was infected by HPV in approximately 1 out of 5 patients.