Recurrent Miscarriage

Miscarriage is a word you never think you will hear, especially if getting pregnant is difficult and requires fertility treatment.

Like many, you thought getting pregnant would be the only issue possible in the world of fertility. The idea of “staying pregnant” or “sustaining a pregnancy” likely never entered your mind.

Medically, physicians refer to miscarriage as a “common phenomenon observed in human reproduction, most often due to a chromosomal abnormality in conception” (Dr. Meyer). Although medically “normal,” one loss can be devastating to a couple, especially after fertility treatments. If it happens a second or third time, we begin to dig deeper to understand why.

Recurrent miscarriage affects approximately 1.3% of women. Unfortunately, a reason why can only be found about 40% of the time.

A chromosomal analysis of the second or third miscarriage is often recommended. This usually requires a D&C procedure to collect the pregnancy tissue. This is the only way to prove that the pregnancy had a chromosomal abnormality.  The most common abnormality is called an aneuploidy — where the embryo had the incorrect number of chromosomes.

These abnormalities are random and there is no treatment needed. But sometimes a miscarriage is discovered to have a partial chromosomal deletion or duplication, which may be a result of one of the parents having a chromosomal abnormality. In these situations the parents will need chromosomal analysis. Only about 3% of recurrent miscarriages are due to a chromosomal abnormality from the parents, but these parents may have miscarriages occur in up to 70% of future pregnancies. IVF with genetic testing of embryos is recommended to prevent a future miscarriage due to a chromosomal abnormality.

For those couples who receive normal results from their chromosomal analyses, our physicians will consider the following as they try to find answers:

• Anatomical factors like a uterine septum, fibroids, or polyps can be detected by an X-ray of the uterine cavity (HSG). In some cases, a pelvic ultrasound or pelvic MRI is needed to further discern abnormalities noted on HSG. Many of these issues can be corrected with minimally invasive surgery.
• Thrombogenic causes such as lupus anticoagulant, anticardiolipin antibodies, or beta 2 Glycoprotein. These are antibodies that may set up small clots between mother and fetal blood vessels, or prevent the cells involved in implantation and formation of the afterbirth from growing. Baby aspirin and low molecular weight heparin (Lovenox) may be helpful. Heparin works by reversing the inhibition of trophoblasts or early placental tissue by these autoantibodies. Heparin also increases the production of hCG, the hormone of pregnancy, by these trophoblasts.
• Ovarian reserve: A lab to determine AMH level (Antimullerian hormone) may prove useful if this has not been done before. This number will reflect a woman’s ovarian reserve. Low AMH levels are associated with increased miscarriage risk, and are typically lower as maternal age increases. Couples may require the use of injectible FSH followed by progesterone suppositories to improve pregnancy rates.
• Maternal Age: The role of maternal age significantly impacts fertility. As a woman ages, her egg quality declines. Poor egg quality will increase the risks for chromosomal issues and miscarriage. Unfortunately, there is no test available to directly assess egg quality.

One in 85 women aged 20, and as high as one in four women at age 40 will have sporadic miscarriages. This is due to abnormal chromosomes in the eggs (aneuploidy). Aneuploidy risk is only 10% in women under the age of 35 and rises to 50% in women aged 43.

For more information, please watch Dr. Meyer’s video on recurrent miscarriage.

Read Dr. Ryan Blazei’s blog article Coping with Pregnancy & Infant Loss.