ASRM releases 2026 guidelines on managing recurrent pregnancy loss

The ASRM published their 2026 guidelines on managing recurrent pregnancy loss (RPL), reviewing which tests and treatments are supported by evidence, which may be considered in certain situations, and which are not routinely recommended.

The American Society for Reproductive Medicine (ASRM) is an authority on reproductive medicine that releases committee opinions and guidelines on fertility-related topics. Their latest committee opinion focuses on recurrent pregnancy loss (RPL).

The ASRM defines RPL as two or more pregnancy losses before 22 weeks, including clinical pregnancies confirmed by ultrasound, or biochemical pregnancies confirmed by blood or urine hCG testing. The losses do not need to be consecutive.

RPL can have many possible causes, and patients are often offered a wide range of tests and treatments, although the evidence can be limited or inconsistent.

The ASRM developed this committee opinion to review the available evidence behind commonly used tests and treatments for RPL, and to provide recommendations on which approaches are supported, which may be considered in certain situations, and which are currently not recommended routinely.

These recommendations can change as more evidence becomes available.

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ASRM’s approach to recurrent pregnancy loss

The ASRM recommends chromosome testing of miscarriage tissue early in the RPL workup, starting with a second miscarriage or a history of RPL.

They recommend newer array-based technologies for miscarriage chromosome testing, such as SNP microarrays, array comparative genomic hybridization (aCGH), and next-generation sequencing (NGS), rather than older methods like conventional karyotyping or FISH.

The results of miscarriage chromosome testing may then help guide further evaluation and treatment decisions.

The ASRM also recommends psychological support, reassurance, and improving overall health before pregnancy for all patients with RPL.

Tests and treatments recommended for all RPL patients

• Chromosome testing of miscarriage tissue. Recommended as a first line evaluation for RPL (see above).
• Preconception optimization.
  • The ASRM recommends optimizing overall health before pregnancy, including management of medical conditions, autoimmune conditions, prenatal folic acid use, smoking cessation, and reducing exposure to secondhand smoke.
  • Obesity, higher alcohol intake, high intensity exercise and higher caffeine intake may be associated with increased miscarriage risk, although evidence is limited.
• Psychological support. The ASRM notes that RPL can have a major emotional impact on both patients and their partners, including increased risks of depression, anxiety, guilt, and stress. They recommend psychological support and counseling for all couples experiencing miscarriage and planning future pregnancy.
• Uterine cavity evaluation and treatment
  • The ASRM recommends uterine cavity evaluation for all women with unexplained RPL, since uterine abnormalities appear to be more common in patients with RPL.
  • 3D ultrasound and saline sonohysterography (saline sonogram) appear to have the highest accuracy for detecting uterine abnormalities, while MRI can also diagnose most congenital uterine anomalies but is usually not used first because of cost (Grimbizis et al. 2015)
  • They state that surgical treatment of uterine septa, endometrial polyps, submucosal fibroids, retained pregnancy tissue, and intrauterine adhesions may be reasonable, although high quality evidence showing improved live birth rates remains limited in many cases.

Tests and treatments recommended for RPL when clinically relevant

• APS testing and treatment
  • Can be considered in patients with recurrent unexplained miscarriages, a history of blood clots, miscarriage after 10 weeks, severe preeclampsia, placental insufficiency, or unexplained preterm delivery. Not recommended when all miscarriages are aneuploid. Referral to an APS specialist is recommended for patients with persistent moderate to high antibody levels or a positive lupus anticoagulant test.
  • Testing can be done using lupus anticoagulant, anticardiolipin antibodies, and anti-β2 glycoprotein-I antibodies, with positive results needing to be confirmed again at least 12 weeks later.
  • Treatment with low-dose aspirin and heparin appears to reduce miscarriage risk in patients who meet APS criteria.
• Thyroid testing and treatment
  • Can be considered in patients with risk factors, symptoms, euploid miscarriages or no miscarriage chromosome testing.
  • Testing is typically done by measuring TSH.
  • Treatment with levothyroxine can be used for overt hypothyroidism (elevated TSH with low free T4) and for some patients with subclinical hypothyroidism (elevated TSH with normal free T4). The ASRM recommends treatment when TSH is >4 mIU/L or above the laboratory upper limit of normal. Treatment is not recommended for euthyroid women (normal TSH and free T4), even if thyroid antibodies are present.
• Testing and treatment of uncontrolled diabetes
  • Can be considered in patients with diabetes risk factors such as obesity, PCOS, prior gestational diabetes, family history of diabetes, or age over 40.
  • Testing can be done by measuring HbA1C.
  • Metformin may be reasonable in some women with PCOS, insulin resistance, and otherwise unexplained recurrent miscarriage, although more studies are still needed.
• Genetic counseling can be considered for patients with known genetic causes, parental translocations, or high-risk family history.
• Parental karyotyping
  • Can be considered when miscarriage testing shows an unbalanced chromosome rearrangement or when miscarriage tissue was not tested.
  • Testing is done by a blood karyotype on both partners.
  • PGT-SR may be reasonable, although data showing its effectiveness is limited.
• Chronic endometritis testing and treatment
  • Can be considered for women with unexplained recurrent miscarriage or infertility.
  • Testing can be done using an endometrial biopsy with CD138 staining, although diagnostic criteria and testing methods vary across studies.
  • Treatment usually involves antibiotics, but study results have been mixed and stronger research is still needed.
• Sperm DNA fragmentation testing
  • Can be considered in patients with otherwise unexplained recurrent miscarriage or infertility.
  • Treatments like varicocele repair, testicular sperm extraction, sperm selection with Zymot, smoking cessation, and lifestyle changes may reduce sperm DNA fragmentation, but it’s not clear if this leads to reduced miscarriage.
• Progesterone supplementation
  • Can be considered in early pregnancy for patients with unexplained recurrent miscarriage and/or vaginal bleeding.
  • Progesterone use during the first trimester has shown mixed results, and more research is still needed to determine whether it improves live birth rates.
• PGT-A
  • Can be considered in women over 40 with a prior aneuploid miscarriage.
  • The ASRM states that PGT-A has not clearly been shown to reduce miscarriage or improve live birth rates in RPL patients, although some studies have suggested possible benefit, especially in older patients.
• Prolactin testing can be considered in patients with symptoms such as anovulation or galactorrhea, although evidence linking prolactin abnormalities directly to recurrent miscarriage remains limited.

Tests and treatments not routinely recommended for RPL

• Immune testing and treatment outside of APS
  • The ASRM notes that immune dysfunction may play a role in some cases of unexplained RPL, especially recurrent euploid miscarriage, but current studies on immune testing and treatments have been limited by poor study design and inconsistent testing methods.
  • They do not recommend routine immune testing or immune treatments for RPL at this time, including NK cell testing, autoimmune testing (outside of APS), IVIG, intralipids, and prednisone.
• ERA
• Microbiome testing
• Inherited thrombophilia testing and treatment
  • Inherited thrombophilias are inherited clotting disorders, such as Factor V Leiden, prothrombin mutations, protein C or S deficiency, and MTHFR variants, that have been studied as possible causes of RPL.
  • The ASRM does not recommend routine thrombophilia testing or treatment with blood thinners like aspirin or low molecular weight heparin, based on studies showing similar thrombophilia rates in women with RPL and the general population (Shehata et al. 2022), as well as randomized trials showing no improvement in live birth or miscarriage rates (Quenby et al. 2023).
• Treatment of adenomyosis/endometriosis specifically for RPL. Although endometriosis and adenomyosis have been linked to miscarriage in some studies, evidence that treatment improves RPL outcomes is limited.
• Use of aspirin/anticoagulants without APS
• Thyroid treatment with normal TSH
• Hyperprolactinemia treatment without ovulatory dysfunction

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Reference

Practice Committee of the American Society for Reproductive Medicine. Electronic address: asrm@asrm.org; Practice Committee of the American Society for Reproductive Medicine. Recurrent pregnancy loss: a committee opinion. Fertil Steril. Published online April 29, 2026. doi:10.1016/j.fertnstert.2026.03.001

 

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Embryoman (Sean Lauber) is a former embryologist and the founder of Remembryo, an IVF research and fertility education website. After working in an IVF lab in the US, he returned to Canada and now focuses on making fertility research more accessible. He holds a Master’s in Immunology and launched Remembryo in 2018 to help patients and professionals make sense of IVF research. Sean shares weekly study updates on Facebook, Instagram, and Reddit regularly. He also answers questions on Reddit or in his private Facebook group.

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