A less common, but equally frustrating and emotional issue, is the occurrence of multiple miscarriages (sometimes referred to as “habitual abortion”). Many patients even say they would much rather have had a negative pregnancy test than experience a miscarriage.
Recurrent miscarriage is one of the many reproductive issues that we evaluate at The Fertility Institute of Virginia. The textbook definition of recurrent miscarriage is three consecutive miscarriages. However, we frequently see couples after two miscarriages (and even one) to help counsel and guide them through the next pregnancy.
The causes of repeated miscarriage fall into a number of general categories:
Genetic – Approximately 8% of recurrent miscarriages are due to a chromosomal abnormality found in one of the parents. Blood testing is performed on both of the parents to assess their chromosome complement.
Anatomic – An abnormality of the uterus can prevent an ongoing pregnancy. Anomalies can occur in the formation of the uterine cavity from birth, or from acquired conditions such as scar tissue, polyps, or fibroids. Most of these can be surgically repaired.
Endocrinologic – Hormonal issues, such as progesterone deficiency, are very common causes of pregnancy loss. In these cases enough progesterone is produced to initiate the pregnancy but not maintain it. Other hormones, such as thyroid, are also checked.
Immunologic – Sometimes antibodies are abnormally produced that affect the viability of the pregnancy. Many of these abnormal antibodies are also associated with clotting abnormalities that subsequently affect blood flow to the uterus and fetus. We perform a series of blood tests to uncover these issues, since treatment for this condition is very satisfying.
This is just a partial list of causes of recurrent miscarriage, but a useful start in most patients. In 60% of couples we find an underlying cause, but unfortunately in 40% of patients we cannot detect the reason. The good news is that even in this undetermined group, half of the couples end up with a successful pregnancy with supervision and good old-fashioned “TLC.”