An evaluation for known causes of recurrent pregnancy loss is usually initiated after 2 or 3 consecutive pregnancy losses. The tremendous emotional impact of each loss may encourage an evaluation sooner than later.
A full Recurrent Pregnancy Loss evaluation includes:
Approximately half of all couples who have experienced 2 or 3 consecutive pregnancy losses will be diagnosed with "Unexplained Recurrent Pregnancy Loss." That is, roughly half of couples seem to have a reason for recurrent loss that is beyond modern medicine's ability to diagnose this cause. This can be frustrating for both the couple and the physician. Although this situation is not ideal, the doctor and patient will be able to rule out potentially repairable pathology in the future.
An estimated 15% of couples (1 in 6) with recurrent pregnancy loss have an anatomic abnormality of the uterus as the primary reason. The two categories of anatomic defects that cause recurrent pregnancy loss are:
1. Abnormalities in the normal process of uterine fusion during embryonic development (Mullerian duct abnormalities such a septate uterus)
2. Abnormalities in the size of or circulation to the uterus due to fibroids, endometrial polyps or scar tissue (Asherman’s syndrome)..
Hormonal causes for recurrent pregnancy loss are generally considered "luteal phase defects." Luteal phase defects are most often thought to result from the effect of inadequate progesterone on the endometrial lining. Thyroid deficiencies may also result in miscarriages.
Certain chromosomal abnormalities are universally accepted by infertility specialists as a cause for recurrent pregnancy loss. Fortunately, these major chromosomal abnormalities are uncommon. They may occur within the maternal or paternal chromosomes. The overall incidence of chromosomal abnormality as the cause of recurrent pregnancy loss is low (less than 5% of couples with recurrent losses).
Immunologic causes of recurrent pregnancy loss are poorly understood. The theories proposed by authorities in this field appear to be constantly evolving. We do know that these are known reasons for miscarriages. We evaluate these factors by measuring in the blood acquired and hereditary thrombophilias. The acquired thromobphilias consist of antiphospholipid antibodies which include antiphospholipid antibodies, anticardiolipin antibodies, and lupus anticoagulant. Hereditary thromophilias can be evaluated by immunicological testing for the MTHFR gene, prothrombin gene, antithrombin III protein C and S activities, and Leiden Factor V gene. Not all patients need all this testing. Patients are evaluated and treated on an individual basis depending on their prior history and evaluation.
Overall, your chance of a successful outcome is excellent. We will try to evaluate all the pertinent factors that may contribute to your losses. Often, there are multiple factors that are responsible for your miscarriages. Therefore, going into the next pregnancy you will know that every reason for your miscarriages has been looked into. We will follow your pregnancy very closely until we see a healthy fetus, and you are comfortable being referred back to your obstetrician.