Many women struggle after miscarriage and feel a variety of emotions ranging from shame, and anger to frustration, sadness, and guilt. As a society, we do not talk about miscarriages enough and it has left many women to suffer alone and in silence. Clinically recognized pregnancy loss (which is defined by seeing the pregnancy on an ultrasound) occurs in 15-25 percent of pregnancies with the majority occurring in the first trimester. However, up to 50 percent of all pregnancies may end in miscarriage, before a woman even knows she is pregnant. According to the American Society for Reproductive Medicine, recurrent pregnancy loss (RPL) is defined as 2 or more failed clinical pregnancies and occurs in approximately 5 percent of women.
What causes recurrent miscarriages?
- Age. One of the most common causes of miscarriage is due to genetic abnormalities in the developing embryo resulting from too many or too few chromosomes. The risk of this occurring is more common as women age due to a reduction in egg quality. This decrease in egg quality occurs slowly at first around age 35 and more rapidly after age 40, which is why we see the higher rate of miscarriage in women over 40.
- You or your partner’s genetics. At birth, men and women typically have 46 chromosomes which contain all of our genetic material. In some cases, you or your partner may have an abnormal number of chromosomes due to genetic translocations or rearrangements of genetic material on chromosomes. This will not impact you or your partner but may affect a developing pregnancy as they will have an unbalanced set of chromosomes and may increase the risk of miscarriage.
- Blood clotting disorder. Certain disorders of the blood may increase your risk of miscarriage. Antiphospholipid antibody syndrome is a disease that has been specifically linked to increasing the risk of miscarriage and may also be associated with blood clots and adverse pregnancy outcomes like pre-eclampsia.
- Hormone and metabolic imbalances. Women with certain medical diseases such as lupus, uncontrolled thyroid disease, elevated prolactin levels or uncontrolled diabetes may have an increased risk of miscarriage.
- Uterine abnormalities. Uterine abnormalities (such as the presence of a septum) can lead to recurrent miscarriages if an embryo implants in that area due to poor vascularization. The presence of fibroids or polyps within the uterus may also increase the risk of miscarriage.
- Immune system. Emerging research shows that our immune system (which is what our bodies use to fight off infections) may play a role in miscarriage if certain cells are over or under-expressed. This may lead to the embryo being unable to implant in the uterus or the uterine lining not be receptive to a developing pregnancy.
- Unexplained. Up to 50 percent of cases of recurrent pregnancy loss are unexplained, meaning that after a full work-up, no cause as to the reason for miscarriage can be determined.
What testing may be done to determine the cause of recurrent pregnancy loss?
- The basic testing for recurrent pregnancy loss starts with a detailed medical history of you and your partner and a physical exam.
- Your doctor will evaluate your uterus to determine whether there are any abnormalities. Testing may include any of the following: ultrasound, hysterosalpingogram, saline sonogram and/or an MRI.
- Hormone testing will be performed to rule out diseases associated with your thyroid, prolactin abnormalities, and diabetes.
- Your ovarian reserve will be assessed to measure egg quantity. This may include testing your anti-mullerian hormone (AMH) and assessing your antral follicle count (AFC) on ultrasound. Egg quality can’t be measured directly, but we know that female age has an indirect correlation to egg quality and low egg quality can increase your chance of miscarriage due to genetic errors.
- You and your partner will be offered genetic screening, which includes a karyotype, (or a map of the number and appearance of your chromosomes) to determine if there are any abnormalities.
- Blood tests will be performed to check for antibodies that are associated with antiphospholipid antibody syndrome.
- Further testing of your immune system may also be performed, but as mentioned earlier, concrete evidence regarding abnormalities of the immune system and their direct relation to pregnancy loss and infertility are lacking as this is still an emerging field in reproductive medicine.
Is there a way to prevent miscarriages?
While there is no one treatment that can completely prevent miscarriages, there are lifestyle factors that can impact your risk of a miscarriage that you may want to avoid.
- Avoid smoking. We know that smoking has profound negative impacts on a woman’s fertility leading to earlier ages of menopause and can also increase the risk of miscarriage when pregnant.
- Limit alcohol intake. Heavy alcohol use (>2 drinks/day) may increase your risk of miscarriage, although the data’s not as clear as it is with smoking’s effects on miscarriage.
- Keep your caffeine consumption in mind. Caffeine consumption over 200 mg/day (typically 2 cups/day) may also put you at a higher risk of miscarriage and over 500 mg (5 cups/day) may increase your chances of having difficulty conceiving. Keep in mind that at-home brewed coffee may have less caffeine than your Starbucks cup.
- Maintain a healthy lifestyle. Being overweight may also put you at a higher rate of miscarriage, thus it is important to maintain a healthy diet and exercise program to maintain a healthy weight.
What treatment is involved with recurrent pregnancy loss?
One silver lining for this diagnosis? The chance of a successful future pregnancy in women with RPL is up to 75 percent regardless of whether or not a cause of pregnancy loss is determined.
Depending on the abnormality found, the plan moving forward may differ. If a uterine abnormality is found, surgery may be recommended to correct it. Hormone imbalances can be corrected by medications and couples in which either partner has a chromosome abnormality will be referred for genetic counseling with the option to move forward with specific fertility treatment. Couples can also elect to undergo fertility treatment with in-vitro fertilization (IVF) and genetic testing of the embryo, known as pre-implantation genetic testing for aneuploidy (PGT-A), which can screen embryos for chromosomal abnormalities and allow for the transfer of single, chromosomally normal embryos. Transferring an embryo that has been genetically screened and found to be normal may reduce the risk of loss due to chromosome abnormalities. Despite this, routine genetic testing is not recommended for everyone and should be a discussion you have with your fertility doctor based on your history.
The most important aspect of recurrent pregnancy loss is to remember your own mental health and well-being. Miscarriages are heartbreaking and devastating. They are not your fault (repeat that to yourself as many times as you need to hear it). If you are struggling to cope with loss after miscarriage it is so important to talk to someone, whether it’s a spouse, friends, your doctor, or a therapist about your feelings. Make sure you are taking care of yourself and being honest about your feelings throughout this process.