Recurrent miscarriages are heartbreaking, and understanding the potential causes is an important first step toward getting the right support. The most well-established causes include chromosomal abnormalities in the embryo, uterine structural problems (like a septate uterus or fibroids), antiphospholipid syndrome (an immune/clotting disorder), and thyroid dysfunction — all of which can be identified through testing and many of which are treatable.
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Recurrent miscarriages are heartbreaking, and understanding the potential causes is an important first step toward getting the right support. The most well-established causes include chromosomal abnormalities in the embryo, uterine structural problems (like a septate uterus or fibroids), antiphospholipid syndrome (an immune/clotting disorder), and thyroid dysfunction — all of which can be identified through testing and many of which are treatable. Hormonal imbalances, PCOS, poorly controlled diabetes, and lifestyle factors like smoking or obesity also play a role. Importantly, roughly 50% of cases have no identifiable cause even after thorough evaluation, which is frustrating but not hopeless — many women in this situation go on to have successful pregnancies. If you've experienced two or more consecutive losses, seeing a reproductive endocrinologist or maternal-fetal medicine specialist is strongly recommended. A standard workup typically includes genetic testing for both partners, pelvic imaging, blood clotting and immune panels, and thyroid screening. You don't have to navigate this alone, and professional evaluation is the most important next step.
Where the AIs Agree
Chromosomal/genetic abnormalities are among the most common causes, present in roughly 50% of individual miscarriages.
Uterine structural issues (fibroids, septum, polyps) are a well-established and often treatable cause.
Antiphospholipid syndrome (APS) is a clearly supported immune/clotting cause, affecting roughly 5–15% of cases.
Thyroid disorders and hormonal imbalances are recognized contributors that are detectable via simple blood tests.
Lifestyle factors (smoking, heavy alcohol use, obesity) are associated with increased risk and are modifiable.
Consulting a specialist for a structured diagnostic workup is universally recommended across all responses.
Where the AIs Disagree
**Definition of "recurrent"**: ChatGPT and Grok define recurrent miscarriage as 2+ losses; Claude uses the more traditional clinical threshold of 3+. This matters because it affects when formal investigation is typically initiated (guidelines vary by country and have been shifting toward 2+).
**Confidence in lesser-known causes**: Claude explicitly flags progesterone deficiency and "weak cervix" as lacking strong evidence, while ChatGPT presents luteal phase defect and cervical incompetence more straightforwardly as established causes — a meaningful difference in how confidently these are framed.
**Role of infections**: ChatGPT gives infections slightly more weight as a contributing factor; Claude and Grok note the evidence is mixed or limited for recurrent (vs. isolated) losses.
**Unexplained cases**: All responses acknowledge ~50% of cases are unexplained, but Grok and Claude emphasize this more prominently as a key caveat, whereas ChatGPT's framing is slightly more cause-focused.
**Tone and depth on emotional impact**: ChatGPT and Grok briefly mention emotional/mental health support; Claude focuses purely on clinical information — a practical difference for someone seeking holistic guidance.