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Nearly 10-25% of pregnancies may end with a miscarriage. In addition to the grief from such a loss, many women and their partners wonder if they will still be able to have a successful pregnancy and deliver a healthy baby afterward. They also wonder what went wrong and if anything they did contributed to their loss. The same is true for those who experience multiple miscarriages, also known as recurrent pregnancy loss (RPL).

While miscarriages are fairly common, recurrent pregnancy loss (RPL) is not. Women are considered to have a recurrent pregnancy loss (RPL) when they have 2 or more spontaneous clinical pregnancy losses (miscarriages) before the pregnancies reach 20 weeks of gestational age. In some jurisdictions, miscarriages are defined as occurring up until 22 weeks of gestational age. A doctor determines whether this has occurred using pregnancy tests and ultrasound.

Estimates suggest approximately 2-5% of women will experience two consecutive miscarriages, and 1% will experience three or more. While the occurrence is low, it is devastating when it happens. The encouraging news is that for those dealing with RPL  60-80% go on to have a healthy pregnancy and baby, although this percentage is lower for older women.

Potential Reasons for RPL

In approximately 50-75% of RPL cases, there is no explanation why RPL occurred. A diagnosis of “unexplained RPL” (URPL) is made if a comprehensive workup finds no genetic, endocrine, anatomic or immune abnormalities.

Despite the fact the cause of RPL is often not known, there are multiple possible explanations for RPL which can be determined by a complete evaluation performed by your physician. These other factors include,

  • genetic abnormalities
  • anatomical issues
  • endocrine conditions such as thyroid disease, hormonal or metabolic disorders
  • infection
  • autoimmunity
  • sperm quality, and
  • lifestyle habits.

Genetic

The majority of early miscarriages occurring in the first 10-12 weeks of pregnancy are related to genetic abnormalities. They often occur because there is either a missing or extra chromosome that makes the embryo or fetus not able to develop normally.

Down syndrome is the most common genetic problem and is the result of an extra chromosome, number 21. These abnormalities are often affected by a woman’s age; however, abnormalities occur randomly in up to 60% of first-trimester pregnancies in human reproduction.

Just as age affects a woman’s ability to get pregnant and deliver a healthy baby, age also increases the risk of miscarriage due to genetic abnormalities: by 10-15% for women 35 and younger and more than 50% for women over the age of 40.

Anatomic

The size or shape of a woman’s uterus may also lead to pregnancy loss. Factors that may cause uterine problems include genetic issues (being born with a septum, extra tissue that divides the uterus), and exposure (before birth) to a medication like DES. Acquired problems such as fibroids (benign tumors) especially if they are in, or near, the uterine cavity, polyps, intrauterine adhesions and adenomyosis (a form of endometriosis marked by the presence of endometrium-like epithelium and stroma outside the endometrium in the myometrium) can also cause miscarriage.

Medical

 There are untreated medical conditions that can increase the risk of miscarriage, including diabetes and thyroid disease. RPL can also be caused by immune or blood-clotting system conditions such as thrombophilia.

 Lifestyle/Environmental

There are lifestyle and environmental factors that do – or may – lead to multiple miscarriages. Smoking and some recreational drugs, such as cocaine, increase the risk. Alcohol consumption of 3-5 drinks per week and more than 3 cups of coffee per day may also be linked to RPL along with being overweight.

 Evaluation

Experts recommend seeing a doctor for a complete workup following two miscarriages, given that a single miscarriage is fairly common. To determine when an evaluation for RPL is appropriate, clinicians must determine the difference between RPL and “sporadic miscarriages.” A clinical pregnancy loss should be documented by ultrasound or histopathological examination and not be only self-reported. Evaluation may occur after two such losses.

Blood tests, genetic screening and ultrasound or special x-ray (hysterosalpingogram) can help determine which factors may be causing recurrent pregnancy loss. For example, blood tests can show if a woman has certain medical, immune, or blood-clotting conditions that might cause RPL. Also, a special blood test called a “karyotype” can examine the chromosomes of women and their male partners.

Some people may have differences in the way their chromosomes are arranged (translocated) which may increase the risk of genetically imbalanced pregnancy losses. Problems with the shape of the uterus may be identified through ultrasound or special x-ray tests. And, tissue from a miscarriage (if available) can be tested for genetic abnormalities.

Treatment

Close to two-thirds of women who experience RPL may be able to get pregnant without any treatment. For certain conditions, medical or surgical treatment may help reduce the risk of additional miscarriages.

Surgery

Surgery can improve or sometimes fix some uterine problems such as those caused by fibroids, scar tissue or a septum. Correcting the shape of the inside of the uterus might lower the chance of miscarriage.

The surgeon may be able to use minimally invasive techniques such as hysteroscopy, a procedure in which a small telescope is passed into the uterus through the cervix. A camera attached to the telescope enables visualization of the inside of the uterus and repair of many types of problems that might be found. This is usually an outpatient procedure with a recovery time of a few days to a week.

Correcting other medical problems

Recurrent pregnancy loss may be related to medical problems including abnormal blood sugar levels, an over-or underactive thyroid gland, or high levels of the hormone prolactin. Treating conditions such as diabetes, thyroid dysfunction, or high prolactin levels can improve the chances of having a healthy, full-term pregnancy.

Genetic screening

Among approximately 5% of couples with RPL, one of the parents has a rearrangement or translocation of their chromosomes. If this is the case, it can result in a fetus with chromosome imbalances that are more likely to cause a miscarriage. The parents’ blood can be studied to see if there is such a rearrangement and if a problem is found, genetic counseling may be recommended.

Although couples with translocations may eventually get pregnant naturally with a healthy baby, fertility treatments such as in vitro fertilization (IVF) may be recommended. Following IVF, embryos can be tested for genetic abnormalities before they are implanted. Embryos without a rearrangement of chromosomes can be selected to increase the chance of a healthy pregnancy and delivery with the transfer of that embryo.

Blood-thinning medicines

Women with autoimmune or clotting (thrombophilia) problems may be treated with low-dose aspirin and heparin. These medicines can be taken during pregnancy to reduce the risk of miscarriage. However, it is essential to talk with a healthcare provider before using because these medications increase the chances of serious bleeding problems during pregnancy. They should only be used with the appropriate indications.

Lifestyle Choices

Being as healthy as possible has a positive impact on the ability to get pregnant and deliver a healthy baby. There are a number of lifestyle habits that can make a difference to the risk of repeated pregnancy loss including not smoking or using drugs such as cocaine. Research also shows that limiting the amount of alcohol and caffeine consumption may help. Being at a healthy weight also improves pregnancy outcomes.

 Stress and Depression

While there is no evidence that mild depression, anxiety and stress cause RPL, couples who experience multiple miscarriages may experience all of these. Anyone dealing with the grief and sadness from RPL should be offered counseling and other types of psychological support to help them cope. Such support helps create a “healthy environment” for a pregnancy and delivery.

Controversial Treatments

Unfortunately, there are controversial treatments that claim to reduce the risk of miscarriages that are not supported by evidence. These include intravenous (IV) infusions of blood products (such as IV immunoglobulin [IVIG]) or medicines such as soybean oil infusion. Any treatment you receive should be recommended by a physician and based on the results of a comprehensive evaluation that considers your unique situation.

The bottom line

Anyone trying without success to get pregnant faces feelings of frustration, sadness, anxiety, and more. For couples experiencing recurrent pregnancy loss, the experience is devastating. Even worse, the reasons are “unexplained” in 50-75% of cases. A doctor should be consulted for a complete work-up following two clinical pregnancy losses.

Evaluation results may help identify any problems and for a number of issues, there is an evidence-based treatment that can help. It may be hard to stay positive under the circumstances, but in approximately 60%-80% of cases, less in older women, couples can go on to get pregnant and deliver a healthy baby. That’s good news to think about!

David Adamson, M.D.
World-renowned, board-certified fertility expert and pioneer David Adamson, MD, founded Advanced Reproductive Care®, Inc. (ARC Fertility) in 1997. Dr. Adamson is a Clinical Professor, ACF, at Stanford University School of Medicine and recognized as one of the country’s top doctors for women. He is past president of the American Society for Reproductive Medicine (ASRM) and a former board member of RESOLVE, the leading nonprofit fertility organization for patients. Board certified in reproductive endocrinology and an internationally sought-after lecturer in reproductive medicine and surgery, Dr. Adamson remains connected to the latest innovations in care by consulting with patients, performing and publishing research articles, leading professional organizations and participating in scientific meetings.

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