Recurrent miscarriage is a devastating medical problem with far-reaching effects on the couple and the clinician..
Recurrent miscarriage is defined as three or more consecutive spontaneous pregnancy losses of less than 20 weeks of gestation. Some studies recently have indicated that the risk of recurrent miscarriage after two consecutive losses is similar to the risk of miscarriage after three losses. Thus, it appears reasonable to start the investigations after two or more consecutive spontaneous miscarriages to determine the cause of the pregnancy loss, especially when the woman is older than 35 years of age, or when the couple has had difficulty conceiving either naturally or after IVF.
Of all clinically documented pregnancies in women of reproductive age, 12-15% end in spontaneous miscarriage, whereas recurrent pregnancy loss occurs in approximately 1-2% of them. The miscarriage rate is as high as 30% when unrecognised pregnancies are taken into account. A previous miscarriage, without history of a viable pregnancy, increases the risk that the subsequent pregnancy will end in miscarriage up to 20%. Two miscarriages, without a live birth, result in a 35% risk of subsequent spontaneous miscarriage, and three miscarriages, without a live birth, result in a 47% risk of subsequent pregnancy loss. A history of one previous live birth reduces the risk of miscarriage by approximately 10%.
Recurrent miscarriage may have a cause distinct from sporadic spontaneous losses, with an inherent factor placing some couples at greater risk for further pregnancy loss. A definite cause of recurrent miscarriage can be established in approximately 60-70% of cases after a thorough evaluation.
The routine work-up for recurrent miscarriage begins with a detailed history of both partners and physical examination of the female partner. A complete list of investigations will include tests to exclude one or more of the following causes: genetic, endocrine, anatomic (uterine abnormalities), immunological, haematological and infectious. Further, attention to plausible iatrogenic/environmental causes will be given. Successful outcome in terms of a live birth occurs in more than two thirds of all couples.