Paternal Factors - Role in Idiopathic Recurrent Pregnancy Losses

Recurrent pregnancy loss (RPL) or habitual miscarriage is the loss of three or more consecutive pregnancies before the 20th week of gestation [36]. The World Health Organization (WHO) has defined a miscarriage as the loss of a fetus or embryo weighing ≤500 g, which would normally be at 20−22 weeks of gestation. RPL affects approximately 1 in 300 pregnancies. However, epidemiologic studies have revealed that 1% to 2% of women experience recurrent pregnancy loss [68]. There are several leading causes of RPL, among them are uterine anatomical defects, (intrauterine adhesions, uterine fibroids or polyps and cervical incompetence), genetic factors, infectious, immunological, environmental and blood dyscrasias. However, despite extensive investigation of female partners in a large number of cases (40%−50%) no cause has been identified and such cases are classified as idiopathic.