Few things are more heartbreaking than experiencing miscarriage, especially more than once. If you have experienced two or more miscarriages in a row, you should talk to your clinician about possible causes for your miscarriages and tests to help identify treatments that may help your body carry a pregnancy to term. For some patients, medications and/or surgery is the answer. For others, in vitro fertilization (IVF) can help.
Recurrent miscarriage, also known as recurrent pregnancy loss, occurs when you experience two or more miscarriages in a row. Recurrent miscarriage occurs for about 2-5% of women.
There are many reasons why you might experience recurrent miscarriage, including uterine issues, hormone imbalances, genetic or chromosomal abnormalities, antiphospholipid syndrome (APS), antithyroid antibodies, cervical weakness, sperm DNA fragmentation, and even unexplained recurrent pregnancy loss.
Below, we’ll detail some of these causes of miscarriage:
Uterine abnormalities such as fibroids, large or numerous polyps, adhesions, and/or a septate uterus (in which a tissue membrane separates the uterus into two chambers) can make it difficult to stay pregnant. Asherman’s syndrome, in which scar tissue builds up in the uterus due to infections, surgery, or cancer treatment, can also contribute to recurrent miscarriage. Disorders that affect the uterine lining, such as endometriosis, are also related to recurrent miscarriage. Ultrasounds or x-rays can help diagnose uterine issues, which may be corrected with surgery.
Several types of hormone imbalances may contribute to recurrent miscarriage, such as polycystic ovary syndrome (PCOS), elevated prolactin, low progesterone, thyroid dysfunction, uncontrolled diabetes, and high androgen levels (1). Testing hormone levels in the blood can help to determine whether hormones may be causing recurrent miscarriages and determine a course of treatment to help balance those hormones.
If the fetal cells have too many or too few chromosomes (also known as aneuploidy), it may lead to a miscarriage. Since fetal chromosomal abnormalities are more common with advanced maternal age, you may consider using IVF so you can conduct preimplantation genetic testing (PGT) on blastocyst-stage embryos to ensure that only chromosomally normal embryos are transferred to the uterus. Chromosomal abnormalities may also occur if one or both parents have a balanced chromosomal rearrangement (2), in which parts of their chromosomes are missing, rearranged, or duplicated. While this may not affect the parent, it may affect their fertility. Conducting cytogenetic analysis on the parents can help determine if this is causing recurrent miscarriage.
APS is an autoimmune disorder that causes the immune system to attack the body’s tissues, which may result in blood clots. Medications can reduce the risk of these clots forming and, in turn, reduce the chance of miscarriage related to APS.
In this immune disorder, antibodies attack your thyroid gland, which can lead to an imbalance in thyroid hormones. The presence of these antibodies is linked to recurrent miscarriage (3).
Sometimes referred to as “cervical incompetence,” this condition occurs when the cervix at the base of the uterus dilates too early in the pregnancy (4). For people at a high risk of cervical weakness leading to miscarriage, a cervical stitch to keep the cervix closed during pregnancy may help support pregnancy, but it may also lead to its own complications, such as uterine contractions, bleeding, or infection.
This occurs when the DNA inside the sperm is fragmented or damaged (5).
Unfortunately, more than half of patients with recurrent pregnancy loss don’t have a diagnosis (6). This makes it difficult to target a fertility treatment that may help.
The first thing to do is to talk to your clinician. They will likely evaluate your medical history and ask you about lifestyle habits that may be affecting your fertility, such as smoking, alcohol use, and nutrition. They will also likely order blood tests, which may include hormone tests, thyroid tests, and/or antibody tests. If they are concerned about uterine issues causing miscarriage, they may order an ultrasound or other tests to check for anatomic problems. Finally, they may order a karyotype – checking your chromosomes – to ensure that your chromosomes are not causing issues with your pregnancy. If you have an opposite sex partner, they may order tests for them, as well.
While some causes of recurrent pregnancy loss can be treated with medication or surgery, others may be helped through IVF treatment. Since embryo quality is critical to a successful pregnancy, IVF can help decrease your risk of miscarriage by assessing egg and sperm quality, assessing overall embryo quality, and conducting preimplantation genetic testing (PGT).
The option to do PGT makes IVF a particularly compelling option for patients concerned about chromosomal abnormalities leading to miscarriage, since PGT allows you to ensure that any transferred embryos are chromosomally normal. PGT not only results in embryos that are more likely to implant but embryos that are more likely to lead to a live birth.
One of the hardest things about miscarriage and IVF is waiting for your body to be ready for another IVF cycle, whether you’re doing another egg retrieval or embryo transfer. This means waiting for levels of human chorionic gonadotropic (hCG) to fall in your blood, which may take anywhere between 1-9 weeks. If you had a dilation and curettage (D&C) procedure after a miscarriage, you may need to wait for your uterus to heal. Your clinician can give you a sense of your particular timeline so you can rest, heal, and prepare.
There’s no way around it, miscarriage is incredibly hard. What makes it even harder is that we don’t have a shared understanding of how to support people who are experiencing miscarriage, or how to reach out for help. Asking for the support you need is vital toward ensuring that you aren’t alone in the process, especially as the support you need changes with time. If you are feeling high levels of anxiety and/or depression, joining a support group or seeing a therapist may strengthen the web of care around you.
Gupta, K., & Kaur, R. (2016). Endocrine dysfunction and recurrent spontaneous abortion: An overview. International Journal of Applied and Basic Medical Research, 6(2), 79. https://doi.org/10.4103/2229-516x.179024
Pal, A., Ambulkar, P., Waghmare, J., Wankhede, V., Shende, M., & Tarnekar, A. (2018). Chromosomal aberrations in couples with pregnancy loss: A retrospective study. Journal of Human Reproductive Sciences, 11(3), 247. https://doi.org/10.4103/jhrs.jhrs_124_17
Xie, J., Jiang, L., Sadhukhan, A., Yang, S., Yao, Q., Zhou, P., Rao, J., & Jin, M. (2020). Effect of antithyroid antibodies on women with recurrent miscarriage: A meta‐analysis. American Journal of Reproductive Immunology, 83(6). https://doi.org/10.1111/aji.13238
Drakeley, A. J., Roberts, D., & Alfirevic, Z. (2003). Cervical stitch (cerclage) for preventing pregnancy loss in women. Cochrane Database of Systematic Reviews. https://doi.org/10.1002/14651858.cd003253
McQueen, D. B., Zhang, J., & Robins, J. C. (2019). Sperm DNA fragmentation and recurrent pregnancy loss: a systematic review and meta-analysis. Fertility and Sterility, 112(1), 54-60.e3. https://doi.org/10.1016/j.fertnstert.2019.03.003
Yu, N., Kwak-Kim, J., & Bao, S. (2023). Unexplained recurrent pregnancy loss: Novel causes and advanced treatment. Journal of Reproductive Immunology, 155, 103785. https://doi.org/10.1016/j.jri.2022.103785
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