A miscarriage is when a pregnancy ends on its own before 24 weeks. If this happens two or more times, it is called a recurrent miscarriage. Naturally occurring pregnancies or miscarriages after IVF treatment are included in this definition, but ectopic pregnancy and molar pregnancy (grape pregnancy) are not included.
How common is recurrent miscarriage?
- Spontaneous pregnancy loss occurs in 15-20% of all pregnancies
- Two consecutive pregnancy losses in a row occur in 2% of all pregnancies
- Three consecutive pregnancy losses occur in 2% of all pregnancies
What Causes Recurrent Pregnancy Loss?
Genetic disorders
Genetic disorders are one of the most common causes of miscarriage, and this is usually due to the chromosomal abnormality of the embryo. Chromosomal abnormality is seen in 80% of all first-trimester pregnancy losses.
Uterine anomalies
About 12 percent of recurrent miscarriages are caused by uterine abnormalities. Structural problems of the uterus including uterus didelphys, uterine septum, unicornuate uterus and bicornuate uterus lead to miscarriage. Structural abnormalities of the uterus can be corrected surgically. Aside from uterus shape, endometrial polyps, fibroids and endometriosis in the uterus can cause miscarriage.
Cervical insufficiency
Cervical insufficiency means that a woman’s cervix shortens, weakens, and begins dilating and opening too early in the pregnancy. Cervical insufficiency may cause miscarriage or preterm birth during the second and third trimesters. Cervical cerclage is applied to prevent miscarriage due to cervical insufficiency.
Blood clotting disorders (Thrombophilia)
Thrombophilia is a blood clotting disorder. Blood clotting during pregnancy causes poor circulation in the placenta and increases the risk of miscarriage. Women who have had 2 miscarriages in a row should be checked for blood clotting disorders. Women diagnosed with thrombophilia should start aspirin and heparin treatment under the supervision of a doctor during the pre-pregnancy period, and the treatment should be continued throughout pregnancy.
Environmental factors
Smoking, excess use of alcohol and caffeine consumption damage egg and sperm quality, make it difficult to conceive and increase the risk of miscarriage. Exposure to certain chemicals, drugs, x-rays, etc. may also increase the risk of miscarriage.
Advanced Age
The risk of miscarriage increases as a woman gets older, even if pregnancy does occur. The risk of miscarriage is 17% in women aged 35-39, while the risk of miscarriage is 52% in women over 40. Because egg quality deteriorates with aging.
Unfortunately, it is not always possible to find the cause of recurrent miscarriages. The cause of 50% of recurrent miscarriages is unexplained.
What tests are done for couples with Recurrent Pregnancy Loss?
After two miscarriages in a row, it is important to get tested to determine the cause of recurrent miscarriages.
These tests include:
- Parental Karyotype
- Hysterosalpingogram (HSG)
- Hysteroscopy
- Transvaginal Ultrasound
- Endometrial Biopsy
- Sperm DNA fragmentation testing
- Thrombophilias tests
- Endocrine tests: Thyroid panel, Progesterone, Prolactin, Fasting Blood Sugar
- Vitamin tests: Folic acid, B12, Vitamin D, Homocysteine
Treatment of recurrent miscarriage
Treatment for recurrent miscarriage varies according to the age of the woman and the cause of the recurrent miscarriage. For example, surgery for uterine anomalies, IVF+PGT for parental chromosomal anomalies, IVF+PGT for advanced maternal age, cerclage for cervical weakness, hormone therapy for endocrine problems can be recommended as treatment options. It is very important to investigate and identify the causes of recurrent miscarriage in detail before starting treatment.
