Losing a pregnancy once is devastating. Losing two or more is a different kind of grief—one that comes with a heavy, persistent question that will not let go: why does this keep happening?
Clinically termed Recurrent Pregnancy Loss (RPL), modern reproductive guidelines from the American Society for Reproductive Medicine (ASRM) now recognize that experiencing two consecutive miscarriages warrants a thorough medical investigation. You no longer have to wait out a third heartbreaking loss before seeking professional answers.
While the emotional weight of multiple losses can feel isolating, the majority of underlying triggers are highly treatable. From silent structural variations in the uterus to underlying autoimmune conditions and hormonal imbalances, advanced diagnostic tracking can unmask the root cause. This comprehensive guide outlines the primary causes of recurrent miscarriage, details what a complete fertility workup entails, and explores the evidence-based treatment options available to help you build a successful path forward.
What Recurrent Miscarriage Means Clinically
The clinical term is recurrent pregnancy loss (RPL). Current guidelines from the Canadian Fertility and Andrology Society (2024) define RPL as two or more pregnancy losses before 10 weeks gestational age, including both clinical and biochemical losses. The American Society for Reproductive Medicine's 2026 committee opinion similarly defines RPL as two or more failed pregnancies.
This definition matters because the threshold for beginning investigation has shifted meaningfully in recent years. Older guidelines often required three consecutive losses before formal evaluation was initiated. The current clinical consensus is clear: two losses in a row deserve a thorough, systematic investigation. As one leading fertility specialist states plainly, "Two losses in a row deserves investigation because finding the cause early often means it can be treated before the next attempt."
The prevalence of RPL in women trying to conceive is estimated at 0.8 to 1.4% when only clinically confirmed losses are counted. When biochemical pregnancies (very early losses confirmed by a positive pregnancy test that does not progress) are included, the prevalence rises to 2 to 3%. These numbers represent a significant number of couples, and the medical knowledge to investigate and treat most causes now exists.
You Are Not Alone: The Emotional Weight This Carries
Before discussing causes and treatment, something must be said about what recurrent miscarriage actually feels like to live through.
The grief after each loss is real and legitimate, regardless of how early the pregnancy was lost. The cumulative weight of multiple losses, combined with the uncertainty of not knowing why, creates a particular form of suffering that has been consistently underrecognised in clinical settings. As confirmed by research cited in Wikipedia's clinical summary of RPL, the condition has been associated with higher levels of depression, anxiety, and stress, and appropriate psychological support is recommended alongside medical management as a standard part of care.
The expectation that couples should simply "try again" without answers is neither compassionate nor clinically sound. A diagnosis is not guaranteed in every case, but the right investigation significantly improves the chances of understanding what is happening and addressing it before the next pregnancy.
Cause 1: Chromosomal Abnormalities in the Embryo
This is the most common cause of pregnancy loss overall, accounting for 50 to 80% of first-trimester miscarriages. Chromosomal abnormalities mean the embryo has an incorrect number of chromosomes (aneuploidy), making it unable to develop to term. The most frequent abnormality is trisomy, where an extra chromosome is present. The risk of chromosomal abnormality in the embryo rises significantly with maternal age. As Wikipedia's clinical review of RPL notes, women over 40 face a miscarriage rate of approximately 50%, largely because of the higher incidence of chromosomal trisomies seen in eggs produced at advanced maternal age.
An important clinical development: as confirmed by NIH StatPearls, the combination of genetic evaluation on miscarriage tissue with an evidence-based assessment for RPL can identify a probable or definitive cause in over 90% of miscarriages. This makes tissue karyotyping from any subsequent loss a critically important diagnostic step that many couples are not offered but should be.
For couples where chromosomal causes are identified, in-vitro fertilisation combined with preimplantation genetic testing for aneuploidy (PGT-A) allows embryos to be screened for chromosomal normality before transfer, significantly improving the chance of a continuing pregnancy.
Cause 2: Antiphospholipid Syndrome the Most Treatable Cause
Antiphospholipid syndrome (APS) is the most important treatable cause of recurrent miscarriage, according to the RCOG Green-top Guideline on recurrent pregnancy loss. APS is an autoimmune condition in which the body produces antibodies (lupus anticoagulant, anticardiolipin antibodies, and anti-B2 glycoprotein-I antibodies) that promote abnormal blood clotting. When this clotting occurs in the placental blood vessels, it cuts off the nutrient and oxygen supply to the developing embryo, causing pregnancy loss.
Antiphospholipid antibodies are present in approximately 15% of women with recurrent miscarriage. An Indian study conducted in Calcutta found that 27.7% of women with otherwise unexplained recurrent pregnancy loss tested positive for antiphospholipid antibodies, suggesting the prevalence in the Indian population may be significant and underdiagnosed.
Also read: https://pubmed.ncbi.nlm.nih.gov/16846864/
The reason APS is highlighted as the most important treatable cause is that treatment is highly effective. The ASRM 2026 committee opinion recommends treatment with low-dose aspirin before conception combined with prophylactic heparin initiated at the time of a confirmed pregnancy. This combination significantly improves live birth rates in women with APS-associated recurrent miscarriage.
APS is identified through a specific blood panel (lupus anticoagulant, anticardiolipin IgG/IgM, and anti-B2 glycoprotein-I IgG/IgM) and requires two positive results 12 weeks apart to confirm the diagnosis. This blood panel is not part of a standard fertility workup and must be specifically requested.
Cause 3: Uterine Structural Problems
The architecture of the uterine cavity directly affects whether an embryo can implant and develop normally. Structural uterine problems are identified in approximately 15% of women with recurrent miscarriage.
The most clinically significant structural causes include:
Uterine septum: A band of fibrous or muscular tissue dividing the uterine cavity, arising from incomplete fusion of the Müllerian ducts during fetal development. It is the most common congenital uterine anomaly associated with recurrent miscarriage. The septum has a poor blood supply and is thought to impair implantation and early embryonic development. Hysteroscopic metroplasty (surgical removal of the septum) is the standard and generally highly effective treatment.
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Uterine fibroids: Submucous fibroids that distort the uterine cavity directly impair implantation and embryonic development. Intramural fibroids that significantly compress the cavity can also contribute. Hysteroscopic or laparoscopic myomectomy addresses these surgically.
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Intrauterine adhesions (Asherman's syndrome): Scarring of the uterine cavity following infection, curettage, or previous uterine surgery reduces the surface area available for implantation. Hysteroscopic adhesiolysis, followed by measures to prevent re-formation of adhesions, is the standard treatment.
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Cervical insufficiency: Painless cervical dilation in the second trimester causing mid-trimester loss, managed with cervical cerclage (a suture placed in the cervix) in subsequent pregnancies. Structural uterine problems are assessed through transvaginal ultrasound, saline infusion sonohysterogram (SIS), hysteroscopy, and where needed, pelvic MRI.
Cause 4: Hormonal and Endocrine Disorders
Hormonal imbalances are among the most common and most treatable causes of recurrent miscarriage. The key conditions are:
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Thyroid disorders: Overt hypothyroidism is associated with a miscarriage risk calculated to be as high as 60% in women not adequately treated, according to the ASRM 2026 committee opinion. Even subclinical hypothyroidism and the presence of thyroid peroxidase antibodies (TPOAb) are associated with increased miscarriage risk. TPOAb prevalence in women of reproductive age is 8 to 14%. Thyroid function should be optimised before any subsequent pregnancy attempt, with TSH targets for pregnancy specifically discussed with the treating endocrinologist.
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Polycystic ovary syndrome (PCOS): PCOS is linked to increased miscarriage risk through insulin resistance, hyperinsulinaemia, and hyperandrogenaemia. Elevated testosterone levels are an independent prognostic factor for subsequent miscarriage in women with recurrent pregnancy loss. Management includes metformin for insulin resistance, careful monitoring in early pregnancy, and optimising weight before conception.
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Hyperprolactinemia: Elevated prolactin suppresses the hormones that support the luteal phase (the post-ovulation phase in which progesterone maintains the endometrial lining). When prolactin-driven luteal phase insufficiency disrupts early pregnancy support, miscarriage can follow. Dopamine agonists (cabergoline, bromocriptine) effectively normalise prolactin levels and are prescribed before and sometimes during early pregnancy.
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Uncontrolled diabetes: Poorly managed blood sugar in the peri-conception period is associated with increased miscarriage risk through multiple mechanisms including impaired endometrial function and placental development. Optimising glycaemic control before conception significantly reduces this risk.
Cause 5: Inherited and Acquired Thrombophilias
Beyond antiphospholipid syndrome, other inherited or acquired conditions that increase blood clotting tendency can impair placental circulation and cause pregnancy loss. These include Factor V Leiden mutation, prothrombin gene mutation, protein C deficiency, protein S deficiency, and antithrombin deficiency.
While the evidence for treating inherited thrombophilia in RPL is less robust than for APS, clinical guidelines recommend thrombophilia screening as part of the RPL workup, particularly in women with losses in the second trimester or those with a personal or family history of blood clots. Low-molecular-weight heparin is used in pregnancy for women with confirmed inherited thrombophilias and a history of pregnancy loss, though trial data on its benefit in unselected RPL populations is mixed.
When No Cause Is Found: Understanding Unexplained RPL
This is the reality that many couples face after a thorough investigation: approximately 50% of recurrent miscarriage cases remain unexplained even after complete workup. This is not a failure of the investigation. It reflects the current limits of medical knowledge about the complex immunological and molecular factors governing early pregnancy.
The most important things to understand about unexplained RPL are:
First, "unexplained" does not mean "untreatable." Supportive care including early pregnancy monitoring, progesterone supplementation in women with bleeding in early pregnancy (supported by the PRISM trial), and dedicated specialist follow-up from the moment of a positive pregnancy test improve outcomes compared to no intervention.
Second, the prognosis after unexplained RPL is better than most couples fear. Research consistently shows that many women with unexplained RPL go on to have a successful pregnancy in subsequent attempts, even without specific treatment.
Third, continued investigation of emerging causes including natural killer cell abnormalities in the endometrium, sperm DNA fragmentation in the male partner, and microbiome disruption of the endometrial environment is advancing. What is unexplained today may have a testable, treatable answer within the next few years.
What a Complete RPL Investigation Covers
A thorough investigation of recurrent miscarriage at Dr. Humayun Speciality Hospital includes the following, tailored to the individual's history and the number and timing of losses:
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Genetic investigations: Karyotyping of both partners to identify chromosomal structural rearrangements that can cause recurrent chromosomally abnormal pregnancies. Genetic analysis of miscarriage tissue from any subsequent loss using microarray technology.
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Immunological and haematological testing: Full antiphospholipid antibody panel (repeated after 12 weeks if initially positive); thrombophilia screen including Factor V Leiden, prothrombin mutation, protein C, protein S, and antithrombin.
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Hormonal and endocrine evaluation: Thyroid function (TSH, FT3, FT4) and thyroid peroxidase antibodies; prolactin; fasting insulin and glucose; testosterone and free androgen index; full hormonal profile including FSH, LH, AMH, and oestradiol.
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Uterine assessment: Transvaginal ultrasound, saline infusion sonohysterogram, and hysteroscopy for direct uterine cavity visualisation. Pelvic MRI when deeper structural assessment is needed.
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Male factor assessment: Semen analysis including sperm DNA fragmentation, which is increasingly recognised as a contributing factor in recurrent pregnancy loss.
Psychological Impact and Holistic Support Protocols
No guide to recurrent miscarriage is complete without acknowledging that the emotional impact is a clinical concern, not a secondary one. Research confirms that RPL is associated with elevated rates of depression, anxiety, grief, and relationship strain, and that couples who receive psychological support alongside medical care have better outcomes than those who receive medical management alone.
At Dr. Humayun Speciality Hospital, the approach to recurrent miscarriage includes clear communication at every stage of investigation and treatment, dedicated counselling referral for couples experiencing the psychological burden of multiple losses, and continuity of care through subsequent pregnancies with early monitoring and specialist support from the moment of a positive test.
Being told "it will probably work next time" without an investigation plan is not adequate care. Every couple experiencing recurrent miscarriage deserves answers, and where answers are not yet available, they deserve supported, closely monitored care.
Specialist RPL Care at Dr. Humayun Speciality Hospital, T. Nagar, Chennai
At Dr. Humayun Speciality Hospital, the women's health and reproductive medicine team provides a structured, evidence-based investigation and management pathway for couples experiencing recurrent pregnancy loss.
Services include comprehensive RPL workup covering genetic, immunological, haematological, hormonal, and structural evaluations; hysteroscopic surgical management of uterine structural causes; specialist hormonal management of thyroid, prolactin, and PCOS-related RPL; APS management with aspirin and heparin protocols through early pregnancy; PGT-A integrated IVF for couples with chromosomal causes; and early pregnancy monitoring with dedicated specialist support in subsequent pregnancy attempts.
Two Losses Deserve Answers
You deserve a clinical team that takes your losses seriously, investigates thoroughly, and supports you both medically and emotionally through what comes next. At Dr. Humayun Speciality Hospital, that is exactly the level of care we are committed to providing.
Experienced two or more pregnancy losses and looking for answers? Chat with our care assistant for quick guidance and support and book a specialist RPL consultation at Dr. Humayun Speciality Hospital, T. Nagar, Chennai.
