Is lifestyle different in male partners experiencing recurrent pregnancy loss compared to men fathering a live birth?

Abstract Background Recurrent pregnancy loss is characterized by three or more consecutive pregnancy losses. Although the causes of recurrent pregnancy loss are often unknown, chromosomal defects and fetal anomalies account for a significant proportion of cases. Previous research has primarily focused on maternal factors, but recent attention has shifted to the role of male lifestyle factors. Objectives This study examined how male lifestyle factors and chronic illnesses affect recurrent pregnancy loss in a Danish cohort. Objectives included analyzing demographic and clinical features, as well as assessing lifestyle factors and pregnancy outcomes. Materials and methods We included 741 males referred to the Danish recurrent pregnancy loss unit between 2009 and 2021, alongside a control group of 1173 males from the PREGCO study. Data on demography, clinical features, lifestyle factors, and pregnancy outcomes were collected and analyzed. Results The recurrent pregnancy loss group had a higher mean age compared to the controls. Although there was a trend suggesting a higher prevalence of obesity in the recurrent pregnancy loss group, statistical significance was not reached. The prevalence of chronic illnesses was similar in both groups. In the recurrent pregnancy loss group, a higher body mass index and history of previous or current smoking were associated with a lower pregnancy rate, and men who never smoked had an increased likelihood of achieving pregnancy. However, these associations lost significance after adjusting for potential confounders. Discussion The study suggests an association between male obesity and smoking, and decreased pregnancy rates after referral for recurrent pregnancy loss. However, further research is needed to understand the underlying mechanisms and establish causality in this association. Conclusion The study reveals potential associations between male smoking, male obesity, and reduced pregnancy rates in individuals referred for recurrent pregnancy loss. These findings emphasize the importance of considering male lifestyle factors in the evaluation and management of recurrent pregnancy loss.