Bottom Line Up Front
Recurrent pregnancy loss (RPL) — two or more pregnancy losses — affects 1–3% of couples. The most common cause is chromosomal abnormality in the embryo (50–60% of cases). Other identifiable causes include uterine anomalies, antiphospholipid syndrome, thyroid dysfunction, and uncontrolled diabetes. Approximately 50% of cases remain unexplained — but even unexplained RPL carries a favorable prognosis for future pregnancy.
Defining Recurrent Loss
ASRM defines recurrent pregnancy loss as two or more clinical pregnancy losses documented by ultrasound or pathology. A "chemical pregnancy" (positive test followed by early loss before ultrasound confirmation) is a pregnancy loss, but most RPL protocols begin evaluation after two clinical losses. You don't need to wait for a third loss to seek answers.
The Evaluation Workup
A thorough RPL workup investigates the most common identifiable causes:
| Category | Tests | What They're Looking For |
|---|---|---|
| Chromosomal | Parental karyotype | Balanced translocations in either partner (found in 3–5% of RPL couples) |
| Uterine | Saline sonogram, hysteroscopy, or MRI | Septate uterus, fibroids, polyps, Asherman syndrome |
| Immunological | Antiphospholipid antibodies (lupus anticoagulant, anticardiolipin, anti-beta-2 glycoprotein I) | Antiphospholipid syndrome (found in 5–15% of RPL) |
| Endocrine | TSH, prolactin, hemoglobin A1c, progesterone | Thyroid dysfunction, hyperprolactinemia, diabetes, luteal phase deficiency |
| Thrombophilia | Factor V Leiden, prothrombin mutation | Inherited clotting disorders (controversial — testing recommended only in specific scenarios) |
Chromosomal Causes: The Most Common Factor
Most early pregnancy losses — whether they occur once or repeatedly — are caused by chromosomal abnormalities in the embryo. This is primarily an egg quality issue that increases with age. For couples with RPL and no other identifiable cause, PGT-A (preimplantation genetic testing for aneuploidy) during IVF can screen embryos before transfer, selecting only chromosomally normal embryos. This doesn't increase the per-transfer pregnancy rate, but it significantly reduces the miscarriage rate per transfer.
Parental Karyotyping
In 3–5% of RPL couples, one partner carries a balanced chromosomal translocation — their chromosomes are rearranged but not missing any genetic material, so they're healthy. However, their eggs or sperm have a high chance of carrying unbalanced chromosomes. PGT-SR (structural rearrangement testing) during IVF can identify embryos with balanced chromosomes for transfer.
Antiphospholipid Syndrome (APS)
APS is an autoimmune condition where antibodies cause abnormal blood clotting, which can disrupt placental blood flow. It's one of the most treatable causes of RPL — treatment with low-dose aspirin (81mg) and heparin during pregnancy significantly improves outcomes, with live birth rates increasing from approximately 10–40% (untreated) to 70–80% (treated).
Diagnosis requires positive antibody testing on two occasions at least 12 weeks apart, plus a clinical history of pregnancy loss or blood clots. A single positive test is not diagnostic.
Uterine Factors
A septate uterus (a fibrous wall partially dividing the uterine cavity) is the most common uterine anomaly associated with RPL. Hysteroscopic septum resection is a minimally invasive outpatient procedure that significantly improves pregnancy outcomes. Large submucosal fibroids and uterine adhesions (Asherman syndrome) can also contribute to RPL and are similarly correctable.
When No Cause Is Found
Despite thorough evaluation, approximately 50% of RPL cases remain unexplained. This is frustrating, but the prognosis is actually encouraging: couples with unexplained RPL after two losses have a 60–75% chance of a successful subsequent pregnancy with no treatment beyond supportive care and monitoring. After three losses, the success rate is still 50–60%.
What Doesn't Help
Immune therapies (intralipid infusions, IVIG, prednisone) for RPL without documented APS or specific immune conditions remain controversial and are not supported by high-quality evidence. Beware of clinics offering expensive immune protocols without clear diagnostic indication.
Emotional Impact
Recurrent loss is grief compounded — each loss reactivates previous grief while adding new layers of anxiety, helplessness, and sometimes relationship strain. These feelings are normal and not a sign of weakness. Professional counseling (specifically with therapists experienced in pregnancy loss), peer support through organizations like the Pregnancy After Loss Support (PALS) community, and honest communication with your partner are all protective factors. Your grief is valid even if the losses were early. Your need for support is legitimate even if well-meaning people say "at least you know you can get pregnant."
Specialized Treatment Options
For RPL patients considering IVF with PGT, international clinics can make this advanced testing more financially accessible.
Explore PGT Options Abroad →