Pregnancy is a time for great joy for the mother-to-be, as she nurtures the unborn baby and waits for 9 months to see and hold it. Unfortunately, some pregnancies last for a few months and may get aborted midway of the gestation period. If consecutive miscarriage or clinical loss of pregnancy happens more than two times before 20 weeks of gestation, such a condition can be termed recurrent pregnancy loss (RPL).
What causes RPL?
The causes of having a recurrent miscarriage can be due to a variety of reasons. It can be genetic, anatomic, medical, lifestyle or environmental, and unexplained causes.
Genetic: A genetic abnormality in the fetus is the most common cause of recurrent loss of pregnancy. In the fetus, any abnormality in the chromosomes may cause developmental changes that do not support survival of the fetus, causing it to spontaneously abort. Age-related factors affect the quality of egg or sperm increasing the risk of miscarriages.
Anatomic: The abnormal shape of the uterus can be a cause of recurrent loss of pregnancy. The presence of a band of tissue called septum inside the uterus can make it too small to hold the developing fetus.
Medical Conditions: Abnormalities of the hormones may impact pregnancy loss. Medical conditions like thyroid, diabetes, polycystic ovary syndrome, blood-clotting disorder and abnormalities of the immune system can also lead to RPL.
Lifestyle or Environmental: Obesity, smoking, increased caffeine consumption, excess alcohol use, and use of recreational drugs can lead to complications in pregnancy and miscarriages.
Unknown Causes: Recurrent miscarriages in more than half of women are not related to any of the mentioned causes.
How to know if you are having a miscarriage?
Typically, miscarriage can cause bleeding and pain, and some can have no symptoms at all. A few symptoms of RPL are:
- Spotting
- Back pain severe than menstrual cramps
- Painful contractions every 5 to 20 minutes
- Clots of tissue passing through vagina
- Rapid decrease in signs of pregnancy
Laboratory Tests to Diagnose Causes of RPL
It is important to find out the cause of RPL so that measures can be taken to prevent RPL. A past medical history is helpful to find the probable cause of recurrent abortion and give a direction to the investigations for RPL. A detailed physical examination is performed and followed by blood tests and imaging tests to examine the uterus and if required special genetic testing is also recommended.
A uterine test is performed to check for abnormalities in the uterus. The tests that help are transvaginal ultrasound, hysterosalpingogram, hysteroscopy, and endometrial biopsy.
- Transvaginal ultrasound: This test creates images and helps to detect fibroids, polyps, or other uterine growths that can cause miscarriages.
- Hysterosalpingogram (HSG): This test helps to view anatomical conditions like fibroids that may lead to pregnancy loss. This also helps to detect endometriosis or infections that can block fallopian tubes.
- Hysteroscopy: This is a surgical procedure performed to determine and treat the conditions like fibroids, large polyps, scar tissues, or other congenital defects of the uterus.
- Endometrial biopsy: This procedure is performed along with a hysteroscopy in which a small piece of tissue from the lining of the uterus is removed to test irregular growth like fibroids, polyps, or other infections.
The blood tests that may help to determine the causes of recurrent abortion include the following:
- Antiphospholipid (aPL) antibody: This blood test checks for the 2 most common antiphospholipid antibodies – lupus anticoagulant and anticardiolipin antibodies. This test helps to detect blood clots or autoimmune diseases that may be the cause of repeated miscarriages.
- Thyroid panel: A thyroid panel test detects the level of thyroid hormones in the blood. Abnormal ranges in the second trimester of pregnancy could be a risk and may lead to miscarriage. Normal levels of TSH and low T3 and T4 hormones interpret hypothyroidism, and normal levels of TSH and high T3 and T4 hormones interpret as hyperthyroidism.
- Thrombophilia test: This test helps to detect the presence of blood clots that increases the risk of miscarriage or other problems during pregnancy.
- Antinuclear antibodies test: This test detects the presence of antinuclear antibodies that are related to adverse conditions in pregnancy. This test is an immunoassay test and positive results with high titers related to autoimmune diseases like systemic lupus erythematosus, systemic sclerosis, and Sjögren’s syndrome that affects pregnancy.
- Hormone tests: This test detects the levels of certain hormones like follicle-stimulating hormone (FSH), anti- Mullerian hormone (AMH) that detects the production of an egg from ovaries, and aging affects the number and quality of the eggs that mature and fertilize and can risk the pregnancy.
Genetic tests to detect the cause of recurrent miscarriage include:
Parental karyotyping: This test helps detect the abnormalities in the chromosomes that can cause recurrent loss of pregnancy. Karyotyping of both parents is done to detect abnormalities in chromosomes.
Having a healthy pregnancy after RPL is possible, if the underlying cause is diagnosed and treated accordingly. It is important to undergo a complete investigation for RPL, as in most cases, there are multiple factors responsible for it.
