Objective: To investigate the influence of consanguineous marriage on male factor infertility in Lebanon, where rates of consanguineous marriage remain high (29.6% among Muslims, 16.5% among Christians).
Design: Clinic-based, case-control study, using reproductive history, risk factor interview, and laboratory-based semen analysis.
Setting: Two IVF clinics in Beirut, Lebanon, during an 8-month period (January-August 2003).
Patient(s): One hundred twenty infertile male patients and 100 fertile male controls, distinguished by semen analysis and reproductive history.
Intervention(s): None.
Main outcome measure(s): Standard clinical semen analysis.
Result(s): The rates of consanguineous marriage were relatively high among the study sample. Patients (46%) were more likely than controls (37%) to report first-degree (parental) and second-degree (grandparental) consanguinity. The study demonstrated a clear pattern of family clustering of male factor infertility, with patients significantly more likely than controls to report infertility among close male relatives (odds ratio = 2.58). Men with azoospermia and severe oligospermia showed high rates of both consanguinity (50%) and family clustering (41%).
Conclusion(s): Consanguineous marriage is a socially supported institution throughout the Muslim world, yet its relationship to infertility is poorly understood. This study demonstrated a significant association between consanguinity and family clustering of male factor infertility cases, suggesting a strong genetic component.