Recurrent Miscarriage: Causes and Assessment

Recurrent Pregnancy Loss: Causes and Assessment

Prof. Dr. İkbal Kaygusuz Last reviewed: 25 September 2026 2 min read

In short: Two or more pregnancy losses are defined as recurrent pregnancy loss, affecting about 1-2% of women. Chromosomal problems, uterine abnormalities, antiphospholipid syndrome and thyroid or other hormonal disorders are the main causes. In about half of couples no clear cause is found despite full assessment, and most of these couples go on to have a successful pregnancy.

What is recurrent pregnancy loss?

Pregnancy loss is the end of a pregnancy before 24 weeks and occurs in about 10-15% of clinical pregnancies. A single miscarriage is usually due to a random chromosomal error in the embryo and is unlikely to recur. Current guidelines recommend assessment after two or more losses.

Causes

Genetic causes

A small number of couples carry a balanced chromosomal translocation that causes no symptoms but can produce embryos with unbalanced chromosomes. Genetic testing of pregnancy tissue helps identify the cause. The risk of chromosomal abnormalities rises with maternal age.

Uterine causes

A uterine septum, large fibroids, polyps or adhesions can make it harder to sustain a pregnancy. They are assessed by 3D ultrasound or hysteroscopy and corrected by hysteroscopic surgery if needed.

Antiphospholipid syndrome

An autoimmune condition that increases blood clotting. When diagnosed, blood-thinning treatment during pregnancy clearly improves outcomes.

Hormonal and metabolic causes

Thyroid disorders, uncontrolled diabetes, polycystic ovary syndrome and high prolactin can increase the risk of loss.

Which tests are done?

Chromosome analysis (karyotype) of both partners, especially if pregnancy tissue was not tested
3D ultrasound or hysteroscopy of the uterus
Antiphospholipid antibodies
Thyroid hormones and antibodies
Blood glucose, prolactin and other hormone tests when indicated

Links between clotting markers and pregnancy loss are an area of research, including a study co-authored by Prof. Dr. İkbal Kaygusuz in women with recurrent loss. Routine assessment, however, relies on evidence-based tests only.

Treatment and the next pregnancy

Treatment targets the cause: correcting a uterine abnormality, blood thinners for antiphospholipid syndrome, treating thyroid disease. For couples carrying a balanced translocation, IVF with preimplantation genetic testing (PGT) is one option. Even when no cause is found, the chance of a successful next pregnancy is high, and close support in early pregnancy is especially important.

Frequently Asked Questions

After how many losses should we be investigated?

Guidelines recommend assessment after two or more losses; earlier assessment may be appropriate over 35 or with a history of infertility.

When can we try again after a miscarriage?

Usually after one period once you have recovered physically. With recurrent losses, completing the assessment first is recommended.

Does stress cause miscarriage?

There is no strong evidence that everyday stress causes miscarriage, but emotional support is important for couples who experience loss.

Sources

The information on this website is for general information only and does not replace a medical consultation.