Recurrent Pregnancy Loss (RPL) Less Common Than You Expect, More Concerning Than you May Think

By: Erica Ferraro

Embarking on our TTC journey, we become acutely aware that the heartbreaking loss of unborn babies can mar the path of parenthood. What remains concealed from us is the prevalence of miscarriages and the distinction between a “normal” miscarriage occurrence and a more severe condition known as RPL. It is important to note that 1 in 4 pregnancies naturally end in miscarriage. That is due to the fact that many of the embryos that humans make are genetically abnormal. Miscarriage itself can be normal. Repetitive, back to back miscarriages can indicate a more significant problem. The lack of education surrounding these crucial issues leads to a cascade of misinformation, heartache, and confusion for countless women and couples striving to conceive.

According to the esteemed American College of Obstetrics and Gynecology (ACOG), RPL is defined as the experience of two or more miscarriages. It is strongly recommended to undergo a comprehensive physical examination and testing after two miscarriages. But how likely is it for someone to suffer repeated miscarriages? Fortunately, only a tiny fraction of women, estimated to be fewer than 5 in 100, endure consecutive miscarriages.

“Even though it may seem impossible, it is important to remember the most common outcome of a next pregnancy in the setting of RPL is a normal ongoing pregnancy!” – Natalie Stentz, MD, Fertility Specialist 

According to the ASRM, “No apparent causative factor is identified in 50% to 75% of couples with RPL. It is important to emphasize to patients with unexplained RPL that the chance for a future successful pregnancy can exceed 50%–60% depending on maternal age and parity.”

Approximately half of all miscarriages occur when an embryo unexpectedly inherits an abnormal number of chromosomes during fertilization. This genetic anomaly is purely a matter of chance and not attributable to any medical condition. Nonetheless, the likelihood of encountering this problem does increase with age. Consequently, many couples undergoing in vitro fertilization (IVF) opt for the expensive yet reassuring PGT-A testing (genetic testing) to eliminate the risk of genetic abnormalities that could lead to a miscarriage before proceeding with an embryo transfer. Poor embryo quality often stems from either compromised egg quality or subpar sperm quality. Being aware of any genetic abnormalities in the embryo allows couples to avoid a miscarriage due to this factor, which would typically go unnoticed in natural conception. Astonishingly, it is estimated that over half of all naturally conceived human embryos end in miscarriage due to genetic abnormalities. Thus, the issue is not as uncommon as we might assume, but experiencing multiple consecutive miscarriages is far less common and warrants more significant concern than commonly believed.

In a small subset of couples grappling with repeated miscarriages, one partner carries a translocation, wherein a segment of a chromosome transfers to another chromosome. While individuals with a translocation usually exhibit no physical signs or symptoms, some of their eggs or sperm may possess abnormal chromosomes. When an embryo receives an excess or insufficiency of genetic material, it frequently culminates in a miscarriage.

Several other medical conditions can heighten the risk of repeated miscarriages:

• Certain congenital uterine disorders: While multiple disorders fall into this category, one of the most linked conditions to miscarriage is having a divided uterus, separated by a tissue wall.
• Asherman syndrome: This condition leads to adhesions and scarring within the uterus.
• Fibroids and polyps: These benign growths manifest within the uterus. This is why during IVF cycles, women are screened for these through a Saline sonogram, and they are removed surgically before an embryo transfer,
• Antiphospholipid syndrome (APS): An autoimmune disorder that affects blood clotting and can cause various medical complications. APS can occur alone or coexist with other autoimmune diseases, such as lupus.
• Diabetes mellitus: Poorly controlled diabetes, mainly when blood sugar levels are not maintained within the normal range, amplifies the risk of pregnancy loss. Managing blood sugar levels before and during pregnancy can mitigate the risk.
• Thyroid disease: Untreated thyroid gland issues can increase the risk of miscarriage. Addressing thyroid problems can reduce the risk.
• PCOS: as defined and discussed earlier in this chapter.

To pinpoint the cause of repeated miscarriages, healthcare professionals should delve into your medical history and previous pregnancies with a comprehensive physical exam.

Blood tests can detect immune system issues, and genetic testing might be performed to identify genetic causes of recurrent miscarriages. Imaging tests may be considered to evaluate whether any uterine abnormalities are contributing to the repeated miscarriages.

Grief is a natural response to the loss of a pregnancy. While physical recovery from a miscarriage may take only a short while, the emotional healing process can be much longer. When faced with multiple miscarriages, it is common to question if you somehow played a role in causing them. But it is important to remember that miscarriages are rarely the result of anything you did or did not do. No matter the timing of the miscarriage, loss is loss, and everyone copes with this grief in their own unique way.

If you have endured more than two consecutive miscarriages, it is crucial to discuss your situation with a fertility specialist. IVF treatments can provide valuable insights into the quality of your eggs and sperm when observed outside your body. Additional tests conducted by your doctor can help uncover any genetic mutations, like the Methylenetetrahydrofolate reductase (MTHFR) mutation. These types of mutations may require special prenatal care for methyl-folate absorption or blood-thinning medications to support a pregnancy, assuming the embryo demonstrates good quality.

Remember, you are not alone if you have experienced RPL. Seeking professional assistance as early as your second miscarriage can empower you with knowledge about your body and help identify any underlying issues contributing to RPL. Understanding is the key to finding hope and healing.

sources:

Why do miscarriages happen? – Mayo Clinic Press

 ^{Evaluation and treatment of recurrent pregnancy loss: a committee opinion (2012) | American Society for Reproductive Medicine | ASRM}

Misjudging early embryo mortality in natural human reproduction – PMC