Recurrent Miscarriage: Causes, Investigation, and What Actually Helps
Sad husband and wife sitting together after recurrent miscarriage
Recurrent miscarriage — defined as three or more consecutive pregnancy losses before 24 weeks — affects approximately 1 to 2% of couples trying to conceive. It is one of the most emotionally devastating experiences in reproductive medicine, and one of the most poorly explained. Many couples are told "bad luck" or "chromosomal problems" without a systematic investigation that might identify a treatable cause.
Dr. Shachi Singh, consultant gynaecologist and fertility specialist at Prakash Hospital, Sector 33, Noida, explains the systematic approach to recurrent miscarriage.
Why Miscarriage Happens — the Common Causes
Chromosomal Abnormalities (Most Common — 50 to 60% of All Miscarriages)
The most common cause of any individual miscarriage is a chromosomal abnormality in the embryo — an extra or missing chromosome that makes the pregnancy non-viable. These are typically random errors in egg or sperm division — not inherited — and the risk increases with maternal age.
In recurrent miscarriage, chromosomal testing of pregnancy tissue (POC — products of conception) from a subsequent loss identifies whether the losses are consistently chromosomally abnormal (suggesting a high random error rate, often age-related) or chromosomally normal (suggesting another cause is responsible).
Occasionally, one partner carries a balanced chromosomal translocation — a structural rearrangement of chromosomes that does not affect the carrier but results in unbalanced chromosomes in embryos. Identified by parental karyotyping (chromosome analysis of both partners' blood).
Antiphospholipid Syndrome (APS)
The most important and most treatable cause of recurrent miscarriage. APS is an autoimmune condition where antibodies (anticardiolipin antibodies, lupus anticoagulant, anti-beta2-glycoprotein I antibodies) attack phospholipid proteins involved in blood clotting. In pregnancy, these antibodies cause microvascular thrombosis in placental blood vessels — impairing placental development and causing miscarriage.
APS accounts for approximately 15 to 20% of recurrent miscarriage cases — and is specifically treatable with low-dose aspirin and low molecular weight heparin (LMWH/Clexane), which together dramatically reduce the risk of further miscarriage. Without treatment, the live birth rate in APS-positive recurrent miscarriage is approximately 10 to 30%. With treatment, it rises to 70 to 80%.
Uterine Structural Abnormalities
The uterine cavity should be a smooth, evenly shaped chamber for implantation and pregnancy growth. Structural abnormalities that can cause recurrent miscarriage:
Uterine septum: The most common and most clinically significant congenital uterine anomaly. A fibrous band divides the uterine cavity — the septum is poorly vascularised and cannot support implantation and placentation. Pregnancies implanting on the septum miscarry. Treated by hysteroscopic septum resection — a straightforward, effective procedure.
Uterine fibroids: Submucosal fibroids (projecting into the cavity) and large intramural fibroids distorting the cavity are associated with implantation failure and early miscarriage. Treated by hysteroscopic or laparoscopic myomectomy.
Asherman's syndrome (intrauterine adhesions): Scar tissue within the uterine cavity reduces implantation potential. Treated by hysteroscopic adhesiolysis.
Cervical incompetence: Causes second-trimester loss rather than first-trimester — recurrent painless second-trimester losses. Treated by cervical cerclage.
Thrombophilias
Inherited clotting disorders — Factor V Leiden mutation, prothrombin gene mutation, protein S and C deficiency, antithrombin III deficiency — impair placental blood flow. Their contribution to recurrent miscarriage is debated — screening is recommended by some guidelines, not universally. Treatment with LMWH is used in selected cases.
Thyroid Disease and Hormonal Factors
Hypothyroidism: Particularly subclinical hypothyroidism with elevated TPO antibodies, is significantly associated with miscarriage risk. Thyroid optimisation (TSH below 2.5 before conception) reduces miscarriage risk.
Hyperprolactinaemia: Elevated prolactin impairs implantation and corpus luteum function. Treated with dopamine agonists (cabergoline).
Luteal phase defect: Insufficient progesterone production after ovulation. Progesterone supplementation (vaginal progesterone) from ovulation through early pregnancy is commonly used.
Male Factor
Sperm DNA fragmentation — damage to the DNA within sperm — impairs embryo development and increases miscarriage risk. Sperm DNA fragmentation testing should be part of recurrent miscarriage workup.
Unexplained Recurrent Miscarriage
Even after complete investigation, no identifiable cause is found in approximately 50% of couples with recurrent miscarriage. The prognosis even in unexplained recurrent miscarriage is not hopeless — with supportive care, approximately 65 to 75% of couples go on to have a live birth in subsequent pregnancies.
The Investigation Panel for Recurrent Miscarriage
Both partners should be investigated
Female:
- Antiphospholipid antibodies (anticardiolipin IgG and IgM, lupus anticoagulant, anti-beta2-GP1) — must be positive on two tests 12 weeks apart for APS diagnosis
- Parental karyotype (chromosome analysis)
- Thrombophilia screen (Factor V Leiden, prothrombin mutation, protein S, protein C, antithrombin III)
- TSH and TPO antibodies
- Prolactin
- Pelvic ultrasound — uterine shape, fibroids
- Hysteroscopy or sonohysterography — uterine cavity assessment
- POC (products of conception) testing from a subsequent loss
Male:
- Semen analysis
- Sperm DNA fragmentation testing
- Parental karyotype
Treatment by Cause
- APS: Low-dose aspirin (75 mg from when trying to conceive) + LMWH (from positive pregnancy test)
- Uterine septum: Hysteroscopic resection
- Thyroid: Optimise TSH below 2.5 before conception and throughout pregnancy
- Inherited thrombophilia (selected cases): LMWH with pregnancy
- Progesterone deficiency: Vaginal progesterone from ovulation
- Unexplained: Supportive care — progesterone supplementation, regular early pregnancy ultrasound, emotional support
Gynaecological and Fertility Care in Noida and Greater Noida
Dr. Shachi Singh at Prakash Hospital, Sector 33, Noida, investigates and manages recurrent miscarriage for couples across Noida and Greater Noida — providing a systematic, thorough investigation and individualised treatment plan.
To book a consultation with Dr. Shachi Singh, call: +91 97023 46853
Clinic Hours: Monday to Saturday, 9 AM – 6 PM | Sunday, 10 AM – 2 PM
Clinic Address: D-12A, 12B, Sector-33, G.B. Nagar, Noida, Uttar Pradesh 201301
This blog is for educational purposes only. Please consult Dr. Shachi Singh for assessment and management specific to your history.
