COMMON CAUSES OF PREGNANCY LOSS – FROM A DENVER FERTILITY CLINIC

Pregnancy loss occurs in approximately 30% of all pregnancies. However, approximately 4% of individuals can experience repeated pregnancy losses resulting in the need for a recurrent pregnancy loss evaluation in order to identify the possible reasons for multiple miscarriages. Couples or individuals may request a recurrent pregnancy loss workup at a fertility clinic.  The workup for recurrent pregnancy loss  is typically done after two miscarriages in a row.

What Causes Recurrent Pregnancy Loss?

There are a number of reasons for recurrent pregnancy loss including chromosomal defects in the parents, hormonal, anatomic, immune disorders, blood clotting disorders, and unknown causes.

Chromosomal Abnormalities – This is when a chromosomal abnormality in the parents is transferred to the fetus causing miscarriage. Chromosomal abnormalities are discovered through a blood test. Chromosomal abnormalities are not correctable. In order to prevent recurrent losses due to chromosomal abnormalities IVF with preimplantation genetic diagnosis is often needed.

Anatomic Abnormalities – Abnormalities in the shape of the uterus and cervix can cause recurrent pregnancy loss. There are abnormalities in the shape of the uterus that woman are born with or there are abnormalities that develop over time. The most common birth defect of the uterus that causes miscarriages is a septum.  A septum is a dividing wall within the uterus, that completely divide the uterus in half.  Other abnormalities of the uterus include uterine scarring, polyps and fibroids. These abnormalities do develop over time. Fortunately most abnormalities of the uterus can be remedied, leading to an increase in the likelihood of a successful pregnancy.

Hormonal Abnormalities– Abnormalities in egg quality can lead to recurrent pregnancy loss. Most woman with severely abnormal egg quality have a higher chance of having a chromosomal abnormal baby.  Because the baby is abnormal the chance of miscarriage is high. Progesterone deficiency is also another common cause of miscarriage. Lastly, thyroid and prolactin hormone  abnormalities can increase the risk of miscarriage.

Immune Abnormalities– Whether immune disorders increase the risk of miscarriage is controversial, however the one immune disorder that is well established to increase the likelihood of recurrent pregnancy loss is Systemic Lupus Erythematous.

Blood Clotting Abnormalities-Depending upon which research study you read, blood clotting disorders such as Factor V Leiden and Prothrombin Gene Mutation may increase your risk for miscarriage.

Environmental Issues – exposure to certain toxins, chemicals, radiation and smoking can increase the chances of a pregnancy loss. Individuals that smoke cigarettes are especially at risk of pregnancy loss due to consistent exposure to harmful substances inherent to tobacco products.

Pregnancy Loss Evaluation

Fertility doctors perform a battery of tests to diagnose the reason(s) for pregnancy loss. The most common initial test is a saline infusion sonography (SIS) where an ultrasound image of the uterine cavity is taken while fluid is injected into the uterus.  By looking at the walls of the uterus carefully while the water is injected the SIS can detect abnormalities in shape, polyps, fibroids or scarring.

Other types of tests include cervical cultures, blood tests and karyotypes. Some individuals may undergo a biopsy of the endometrium to detect any hormonal abnormalities.

Pregnancy Loss Therapy

Treatment obviously depends on the problem causing the repeated loss of pregnancy. Anatomic causes often require surgery to treat the cause, while autoimmune issues are often treated with Heparin. Chromosomal abnormalities  can be treated with Preimplantation genetic diagnosis.

Approximately 70% of couples evaluated by a reproductive endocrinologist ,with two or more pregnancy losses will have  a cause for those losses. These individuals typically end up having a successful pregnancy with treatment.