Recurrent Miscarriage: Causes & Investigations

Losing a pregnancy can be devastating, and experiencing multiple miscarriages can leave you feeling helpless and uncertain about the future. Recurrent miscarriage—defined as two or more consecutive pregnancy losses—affects about 1-2% of couples trying to conceive. However, in many cases, an underlying cause can be identified and treated, improving your chances of carrying a pregnancy to term.

What Causes Recurrent Miscarriage?

Several factors can contribute to recurrent pregnancy loss, including genetic, hormonal, anatomical, immune, and lifestyle-related causes.

1. Genetic Causes

• Chromosomal Abnormalities – Around 50-60% of first-trimester miscarriages are caused by random genetic abnormalities in the embryo, often due to an extra or missing chromosome (aneuploidy).
• Parental Chromosomal Translocations – In 2-5% of couples with recurrent miscarriage, one partner carries a balanced translocation, increasing the risk of chromosomally abnormal embryos.

2. Hormonal & Endocrine Disorders

• Polycystic Ovary Syndrome (PCOS) – Women with PCOS have a 20-40% increased risk of miscarriage due to insulin resistance and hormonal imbalances.
• Thyroid Dysfunction – Both hypothyroidism and hyperthyroidism can affect implantation and fetal development.
• Uncontrolled Diabetes – Poorly managed diabetes can increase miscarriage risk.
• Low Progesterone (Luteal Phase Defect) – Progesterone is essential for maintaining pregnancy, and deficiencies may lead to early pregnancy loss.

3. Anatomical Causes

• Uterine Septum – A congenital malformation where a fibrous band divides the uterus, increasing miscarriage risk.
• Fibroids & Polyps – Large fibroids or polyps inside the uterus can interfere with implantation.
• Incompetent Cervix – A weak cervix can open early in pregnancy, leading to second-trimester loss.

4. Immune & Blood Clotting Disorders

• Antiphospholipid Syndrome (APLS) – An autoimmune disorder that causes blood clotting issues, linked to 15% of recurrent miscarriages.
• Thrombophilia – Genetic blood clotting disorders (e.g., Factor V Leiden) can impair blood flow to the placenta.

5. Lifestyle & Environmental Factors

• Smoking – Women who smoke have a 16-20% increased risk of miscarriage.
• Alcohol & Caffeine – Excessive alcohol and caffeine intake are associated with a higher risk of pregnancy loss.
• Extremes of weight – Both high and low BMI can disrupt hormone balance and implantation.

Investigations for Recurrent Miscarriage

To determine the cause of recurrent pregnancy loss, a series of tests may be recommended:

1. Genetic Testing

• Karyotyping (Parental Chromosome Testing) – Checks for chromosomal translocations in both partners.
• Preimplantation Genetic Testing (PGT) – Screens embryos for chromosomal abnormalities before IVF.

2. Hormonal & Endocrine Testing

• Thyroid Function Tests (TSH, T3, T4, Thyroid Antibodies)
• Blood Sugar & Insulin Resistance Tests (HbA1c, GTT)
• Progesterone Levels & Luteal Phase Assessment

3. Uterine & Structural Assessments

• Pelvic Ultrasound – Checks for fibroids, polyps, or uterine abnormalities.
• Hysteroscopy – A minor surgical procedure may be required to further examine the uterus.

4. Blood Clotting & Immune System Tests

• Antiphospholipid Antibody Panel – Diagnoses APLS.
• Thrombophilia Panel – Screens for inherited clotting disorders.

Treatment Options for Recurrent Miscarriage

Once an underlying cause is identified, treatment can significantly improve the chances of a successful pregnancy.

1. Genetic Treatments

• PGT with IVF – For couples with chromosomal translocations, IVF with genetic screening increases the chances of a healthy embryo.

2. Hormonal & Endocrine Treatments

• Thyroid & Diabetes Management – Proper control of thyroid function and blood sugar levels reduces miscarriage risk.
• Progesterone Supplementation – Supports early pregnancy in women with luteal phase defects.

3. Uterine Surgery

• Hysteroscopic Surgery – Correcting uterine septum, fibroids, or adhesions to improve implantation.

4. Blood Clotting & Immune Therapies

• Aspirin & Heparin Therapy – Helps prevent clotting issues in women with APLS.
• Steroid Therapy – May be considered for certain immune-related causes.

5. Lifestyle Modifications

• Quit smoking & reduce alcohol intake
• Maintain a healthy BMI – Aim for a BMI between 18-25 for optimal fertility.
• Reduce stress & improve sleep quality

When to See a Fertility Specialist

If you’ve experienced two or more consecutive miscarriages, it’s essential to seek medical advice. A fertility specialist can help diagnose underlying causes and create a personalised treatment plan.

Take the Next Step in Your Fertility Journey

Recurrent miscarriage can be emotionally and physically exhausting, but help is available. Dr. Basu provides compassionate, evidence-based care to support you in achieving a healthy pregnancy.

Book a consultation today to discuss testing and treatment options.