ByDr. Shachi Singh•5 June 2026

Recurrent Miscarriage: Causes, Investigation, and What Actually Helps

Sad husband and wife sitting together after recurrent miscarriage

There is a particular loneliness in recurrent miscarriage. Each loss carries its own grief. And then, with it, the question that becomes increasingly urgent with each one: why does this keep happening?

The reassurance that is often offered — "it's very common," "most women go on to have a healthy pregnancy," "just try again" — is not always wrong, but it is consistently inadequate. It does not tell a woman why her pregnancies keep ending. It does not give her something to act on. And it leaves her in the impossible position of facing another pregnancy carrying the same unresolved uncertainty.

Recurrent miscarriage is a medical diagnosis that warrants systematic investigation. There are identifiable causes for a significant proportion of cases, and there are treatments that genuinely improve outcomes. Finding them requires a structured clinical approach — not hope alone.

Dr. Shachi Singh, consultant gynaecologist at Prakash Hospital, Sector 33, Noida, guides women and couples through recurrent pregnancy loss investigation and management. This guide covers the definition, causes, investigations, and treatment options.

What Is Recurrent Miscarriage?

The international definition has shifted over time. Traditionally defined as three or more consecutive first-trimester miscarriages, most current guidelines — including those from the European Society of Human Reproduction and Embryology (ESHRE) — now recommend investigation and treatment after two consecutive miscarriages.

This change reflects both the emotional toll of repeated loss and the evidence that the causes identified after two losses are the same as those found after three — and that delaying investigation until a third loss occurs simply means another pregnancy is lost before action is taken.

Recurrent pregnancy loss (RPL) affects approximately 1 to 5% of couples attempting pregnancy. Approximately 30 to 50% of cases remain unexplained after full investigation — which is frustrating but also means that significant improvement in outcomes is possible in the 50 to 70% where a specific cause is found.

The Causes — What Investigation Looks For

Chromosomal Abnormalities in the Embryo

The most common cause of any individual miscarriage — accounting for 50 to 70% of first-trimester losses — is a chromosomal error in the embryo (aneuploidy). Most of these are random errors in cell division during fertilisation or early development, not related to the parents' chromosomes.

In younger women with RPL, sporadic chromosomal errors in successive pregnancies can occur by chance without a specific underlying cause. In older women, the rising rate of chromosomal errors in eggs with advancing age means each pregnancy carries a higher miscarriage risk independently.

What testing shows: Products of conception (POC) chromosomal analysis — tissue from the miscarriage analysed for chromosomal abnormalities — can confirm whether a specific loss was chromosomally caused. If a chromosomal abnormality is found in the products of conception, that loss was unlikely to have been preventable by any intervention.

Parental karyotyping: A small percentage (3 to 5%) of couples with RPL have a chromosomal rearrangement in one parent — typically a balanced translocation where chromosomal material is rearranged but no important content is lost in the parent- but can produce unbalanced chromosomes in embryos, causing recurrent loss. Identified through blood test karyotyping of both partners. If found, pre-implantation genetic testing (PGT-SR) during IVF can select chromosomally balanced embryos.

Antiphospholipid Syndrome (APS)

Antiphospholipid syndrome is the most important treatable cause of recurrent miscarriage. It is an autoimmune condition in which the immune system produces antibodies (lupus anticoagulant, anticardiolipin antibodies, anti-beta-2-glycoprotein-I antibodies) that cause abnormal blood clotting in the placental blood vessels, leading to recurrent pregnancy loss.

APS is found in approximately 15% of women with recurrent miscarriage. Treatment — low-dose aspirin combined with low molecular weight heparin (LMWH) injections throughout pregnancy — dramatically improves live birth rates in women with APS-related RPL. This is one of the most evidence-based treatments in reproductive medicine.

Testing: Blood tests for lupus anticoagulant, anticardiolipin antibodies, and anti-beta-2-GP-I antibodies. Testing must be done twice, at least 12 weeks apart, to confirm the diagnosis (a single positive result can be transient and non-diagnostic).

Uterine Abnormalities

Structural problems within or with the shape of the uterine cavity prevent the embryo from implanting securely or developing normally:

Uterine septum: A congenital partition of fibrous, poorly vascularised tissue dividing the uterine cavity. An embryo implanting on the septum receives inadequate blood supply and growth support. Uterine septa are the most common uterine cause of recurrent miscarriage. Treatment by hysteroscopic resection (removing the septum through the cervix without abdominal incisions) has a well-documented improvement in pregnancy outcomes.

Intrauterine adhesions (Asherman's syndrome): Scar tissue within the uterine cavity, usually from previous uterine procedures — D&C after miscarriage, uterine infection, or surgery. Reduces the functional uterine lining available for implantation. Treated hysteroscopically with adhesiolysis.

Submucosal fibroids: Fibroids projecting into the uterine cavity reduce implantation rates and are associated with increased miscarriage risk and are removed hysteroscopically.

Congenital uterine anomalies: Bicornuate uterus, unicornuate uterus, and other developmental anomalies affect pregnancy outcomes variably. Assessment and management depend on the specific anomaly found.

Testing: Transvaginal ultrasound, saline infusion sonography, and hysteroscopy are the investigations for uterine abnormalities.

Hormonal and Metabolic Causes

Thyroid disorders: Both hypothyroidism and Hashimoto's thyroiditis (autoimmune thyroid inflammation, even without overt hypothyroidism) are associated with increased miscarriage risk. Thyroid antibodies independently increase miscarriage risk. TSH should be tested in all women with RPL; the target TSH in pregnancy is below 2.5 mIU/L. Treatment with levothyroxine, where indicated reduces miscarriage risk.

PCOS and insulin resistance: Women with PCOS have elevated miscarriage rates, thought to be related to the elevated LH levels and insulin-resistant characteristics of the condition. Metformin has been studied in PCOS-related RPL; evidence on its effectiveness is mixed, but it is often used in women with significant insulin resistance.

Elevated prolactin: Hyperprolactinaemia is associated with early pregnancy loss and luteal phase insufficiency. Treatable with dopamine agonists (cabergoline, bromocriptine).

Luteal phase insufficiency: Inadequate progesterone in the second half of the cycle may not adequately support early implantation. Progesterone supplementation (vaginal pessaries or oral capsules) in early pregnancy after conception is commonly used, particularly in women with RPL. Recent evidence from the PRISM trial suggests progesterone supplementation reduces miscarriage specifically in women who have had previous losses.

Thrombophilias — Inherited Clotting Disorders

Inherited thrombophilias — genetic conditions that increase the tendency to form blood clots — include the Factor V Leiden mutation, prothrombin gene mutation, protein C deficiency, protein S deficiency, and antithrombin deficiency. Their role in recurrent miscarriage is more debated than APS, and current evidence does not support treating all inherited thrombophilias with anticoagulation in the same way as APS.

Testing for inherited thrombophilias is included in many recurrent miscarriage panels in India. Management is individualised — the presence of a thrombophilia in a woman with RPL may warrant anticoagulation during subsequent pregnancies, but the decision requires careful clinical assessment.

Immunological Factors

Beyond APS, other immunological mechanisms have been proposed as causes of RPL — natural killer cell abnormalities, HLA compatibility between partners, alloimmune responses. This is an active and evolving area of research. Some of these investigations are offered at specialist centres; many have not yet been proven to improve outcomes when treated and remain investigational.

Unexplained RPL

Despite a full investigation, approximately 30 to 50% of cases of recurrent miscarriage remain unexplained. This does not mean no cause exists — it means current investigation methods have not identified one. The prognosis for unexplained RPL is relatively good: studies suggest 65 to 75% of women with unexplained RPL will have a successful subsequent pregnancy with supportive care alone — including progesterone supplementation and "tender loving care" (attentive early pregnancy monitoring).

The Standard Investigation Panel

A systematic investigation for recurrent miscarriage should include

Antiphospholipid antibodies: Lupus anticoagulant, anticardiolipin antibodies IgG and IgM, anti-beta-2-glycoprotein-I antibodies — tested twice, 12 weeks apart
Parental karyotyping (both partners): Identifies balanced translocations
Uterine assessment: Transvaginal ultrasound, saline infusion sonography, or hysteroscopy for definitive cavity assessment
Thyroid function: TSH and thyroid peroxidase antibodies (TPO antibodies)
Hormonal profile: Prolactin, Day 2/3 FSH and oestradiol
Full blood count and iron studies
Products of conception chromosomal analysis: If products are available from a subsequent loss

Additional tests — inherited thrombophilia screen, NK cell testing, HLA typing — are offered selectively based on the individual clinical picture.

What Genuinely Helps in the Next Pregnancy

Treatment is matched to identified causes

APS: Low-dose aspirin from the time of the positive pregnancy test, plus LMWH injections throughout pregnancy — improves live birth rate from approximately 10% (without treatment) to 70 to 80%
Uterine septum: Hysteroscopic resection before the next pregnancy
Thyroid disorders: Levothyroxine to achieve TSH below 2.5 mIU/L before conception
Progesterone supplementation: Recommended for all women with previous miscarriage, regardless of identified cause, from positive pregnancy test to 12 weeks — supported by recent clinical trial evidence
Parental chromosomal translocation: Pre-implantation genetic testing (PGT-SR) during IVF selects chromosomally balanced embryos
Supportive care: Regular early pregnancy monitoring, reassurance, and attentive care by an obstetrician who knows the history — independently associated with better outcomes even in unexplained RPL

Recurrent Miscarriage Care in Noida and Greater Noida

Dr. Shachi Singh at Prakash Hospital, Sector 33, Noida, provides recurrent pregnancy loss investigation and management for women and couples across Noida and Greater Noida — including the complete diagnostic workup, hysteroscopic surgical treatment of uterine causes, hormonal management, and closely monitored early pregnancy care.

If you have experienced two or more consecutive miscarriages and have not yet had a systematic investigation, that investigation is the right next step.

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

Frequently Asked Questions

How many miscarriages before an investigation is done?

Current guidelines recommend investigation after two consecutive miscarriages. Waiting for three is no longer considered the standard — causes found at two are the same as those found at three, and another pregnancy lost before investigation is avoidable.

What is the most common treatable cause of recurrent miscarriage?

Antiphospholipid syndrome (APS) is the most important treatable cause, found in approximately 15% of women with RPL. Treatment with aspirin and heparin during pregnancy significantly improves live birth rates.

Does progesterone help with recurrent miscarriage?

Recent evidence (the PRISM trial) suggests progesterone supplementation from the time of a positive pregnancy test reduces miscarriage in women with previous losses, particularly those with previous bleeding in early pregnancy. It is widely recommended alongside other specific treatments.

What if no cause is found?

Approximately 30 to 50% of RPL remains unexplained after full investigation. The prognosis is relatively positive — 65 to 75% of women with unexplained RPL achieve a successful subsequent pregnancy. Progesterone supplementation, careful early pregnancy monitoring, and supportive care from an attentive gynaecologist improve outcomes even without a specific identifiable cause.

This blog is written for educational and informational purposes only. Please consult Dr. Shachi Singh or a qualified gynaecologist for investigation and management specific to your situation.