New ASRM Recurrent Pregnancy Loss Guidelines 2026: What Changed and What It Means for You
If you have experienced the heartbreak of more than one pregnancy loss, you may have been told you needed to wait for a third loss, to wait for the "right" diagnosis, to wait before anyone would look deeper. The good news: that's all changing.
The American Society for Reproductive Medicine (ASRM) released updated guidelines on recurrent pregnancy loss (RPL) in 2026; the first major revision since 2012. For patients and clinicians alike, these updates shift how we define, evaluate, and approach care after pregnancy loss.
Below, we break down what's new, what it means, and where a functional medicine lens adds even more clarity.
What Is Recurrent Pregnancy Loss?
Old definition (prior to 2026): Three or more consecutive pregnancy losses before 20 weeks gestation.
New ASRM definition (2026): Two or more pregnancy losses before 22 weeks, and the losses do not need to be consecutive. Importantly, biochemical pregnancies (pregnancies confirmed by a urine or blood hCG test, even without ultrasound confirmation) now count toward the RPL diagnosis.
This shift is significant. Previously, biochemical pregnancies, early losses that many people experience and grieve deeply, were often dismissed or excluded. The new guidelines recognize that these losses carry the same emotional weight and the same implications for recurrence risk as clinical losses. They also acknowledge that access to early ultrasound varies, making hCG-confirmed loss a more equitable standard.
Why Now? What Prompted the Update?
The previous ASRM guidelines dated back to 2012, over a decade of new research, new testing technologies, and a growing understanding of the emotional and physical complexity of pregnancy loss. This update reflects that accumulated knowledge and brings U.S. guidelines more in line with international standards from organizations like ESHRE (European Society of Human Reproduction and Embryology).
Testing Recommended for ALL Patients with RPL
The 2026 guidelines establish a baseline workup that should be offered to every patient with recurrent pregnancy loss, regardless of how many losses have occurred:
Chromosome Testing of Pregnancy Tissue Rather than waiting or relying on basic pathology, the ASRM now recommends offering genetic analysis of miscarriage tissue to all RPL patients, starting with the second loss. Newer technologies including next-generation sequencing (NGS), array comparative genomic hybridization (aCGH), and SNP microarrays are preferred over older methods like conventional karyotyping or FISH testing. These modern approaches are more accurate and cost-effective, and they provide meaningful information that can guide future care decisions and offer emotional closure.
Uterine Cavity Evaluation A uterine cavity evaluation is now recommended for all women with unexplained RPL. Structural abnormalities including uterine septa, polyps, submucosal fibroids, intrauterine adhesions, and retained tissue are more common in this population than previously appreciated. The preferred imaging methods are 3D ultrasound and saline sonohysterography (saline sonogram). When abnormalities are found, surgical treatment may be reasonable, though high-quality evidence for improved live birth rates with each intervention varies.
Preconception Health Optimization The guidelines emphasize optimizing overall health before pregnancy for all RPL patients. This includes managing existing medical conditions, correcting nutritional deficiencies (including prenatal folic acid), smoking cessation, and reducing exposure to secondhand smoke. Obesity, high alcohol intake, high-intensity exercise, and high caffeine consumption may also be associated with increased miscarriage risk, though evidence varies.
Psychological Support The ASRM explicitly acknowledges that recurrent pregnancy loss carries a profound emotional impact including elevated risks of depression, anxiety, grief, and stress; and recommends that psychological support and counseling be offered to all couples experiencing RPL. This is not an afterthought; it is embedded as a standard of care.
Testing Recommended When Clinically Indicated
Beyond the baseline workup, certain tests and interventions are now recommended when specific risk factors or symptoms are present:
Antiphospholipid Syndrome (APS) Testing APS is one of the most well-established treatable causes of RPL. Testing including lupus anticoagulant, anticardiolipin antibodies, and anti-beta-2 glycoprotein-I antibodies is recommended for patients with unexplained losses, prior blood clots, losses after 10 weeks, or severe preeclampsia. Positive results must be confirmed at least 12 weeks later. Treatment with low-dose aspirin and heparin appears to reduce miscarriage risk in confirmed APS.
Thyroid Function (TSH) Thyroid testing is recommended when risk factors or symptoms are present or when losses are euploid (chromosomally normal) with no other explanation. The ASRM recommends treatment when TSH exceeds 4 mIU/L, even in the subclinical range. Notably, treatment is not recommended for women with normal thyroid function who test positive for thyroid antibodies alone, reflecting updated evidence.
Blood Sugar and Metabolic Evaluation (HbA1c) For patients with PMOS, obesity, prior gestational diabetes, or a family history of diabetes, HbA1c testing is reasonable. Poorly controlled diabetes is associated with increased miscarriage risk. Metformin may be considered in some cases of PMOS with insulin resistance and unexplained RPL, though more research is still needed.
Parental Karyotyping Parental chromosome testing can be considered when pregnancy tissue reveals an unbalanced structural chromosomal abnormality, when there is a known family history of genetic conditions, or in select high-risk situations. This is a shift from previous guidelines, which recommended routine parental karyotyping for all RPL couples.
Prolactin Testing Prolactin can be considered in patients with symptoms such as irregular cycles or galactorrhea (unexpected milk production), though evidence directly linking elevated prolactin to RPL remains limited.
The Role of Progesterone: What the Guidelines Actually Say
Progesterone is essential for achieving and maintaining early pregnancy; it prepares the uterine lining and has important immune-modulating effects. So where do the new guidelines land?
What IS supported: Vaginal progesterone may be offered in early pregnancy for patients with a history of unexplained recurrent miscarriage, particularly when vaginal bleeding is present. This is to be done through shared decision-making between patient and provider, acknowledging that evidence shows modest benefit in specific subgroups (especially women with prior losses who experience threatened miscarriage).
Interestingly, some data suggests benefit when progesterone is started before confirmed pregnancy in the luteal phase, approximately 3 days after the LH surge rather than after a positive test. This reflects an important nuance that practitioners using a more proactive approach have long understood.
What is NOT supported: The ASRM is explicit: there is no evidence supporting the practice of routinely checking progesterone levels in unassisted pregnancies and supplementing based on the level alone. This is an important distinction. Progesterone therapy in RPL requires clinical context, appropriate timing, and individualized decision-making, not reflexive supplementation based on a single lab value.
What Is NOT Recommended (and Why This Matters)
One of the most important aspects of the new guidelines is what they explicitly do not recommend. Several widely marketed interventions lack sufficient evidence and are not part of the standard RPL workup:
Routine immune testing panels - including NK cell testing (circulating CD16 NK cells and mucosal NK cells), HLA typing, cytokine profiles, and anti-paternal antibody panels are not recommended. While immune dysfunction may play a role in some cases of unexplained RPL, particularly with euploid losses, current studies are limited by inconsistent testing methods and poor study design.
Intralipid infusions are not supported by sufficient evidence for routine use in RPL.
IVIg (intravenous immunoglobulin) is not recommended for routine RPL treatment.
Anticoagulation therapy (blood thinners like heparin or low-molecular-weight heparin) is not recommended for inherited thrombophilias (such as Factor V Leiden or MTHFR variants) without a confirmed APS diagnosis. The evidence does not support their routine use in RPL without specific indications.
MTHFR variants alone are not considered a cause of RPL, and treatment targeting MTHFR in the absence of other findings is not supported.
What These Guidelines Get Right, + Where Functional Medicine Goes Further
The 2026 ASRM guidelines represent a meaningful step forward: lower diagnostic thresholds, better testing technologies, recognition of emotional wellbeing, and more nuanced guidance on commonly used interventions. These changes align with what many integrative and functional medicine practitioners have advocated for years.
But guidelines represent evidence floors, the minimum standard of care supported by large-scale research. They don't capture the full complexity of an individual's physiology.
At Sun Valley Natural Medicine, our evaluation of recurrent pregnancy loss includes a deeper look at:
Comprehensive thyroid function: not just TSH, but free T3, free T4, and thyroid antibodies in full context
HPA axis (adrenal) function: how chronic stress and cortisol dysregulation affect progesterone production and implantation
Gut health and systemic inflammation: nutrient absorption, inflammatory markers, and the gut-hormone connection
Nutrient status: vitamin D, folate (MTHFR-aware), B12, iron, omega-3s, and antioxidants that support a healthy pregnancy
Blood sugar regulation and insulin sensitivity: beyond a single HbA1c
Circadian rhythm and sleep quality: often overlooked drivers of hormonal disruption
Environmental exposures: endocrine disruptors that affect implantation and fetal development
A diagnosis of "unexplained" RPL often means the right questions haven't been asked yet. Our goal is to leave nothing unexplored so that your path forward is grounded in your whole picture, not just a panel of standard labs.
Key Takeaways
Two losses is enough. You don't have to wait for a third to ask for a full evaluation.
Biochemical pregnancies count. Your early losses are valid and medically relevant.
Modern chromosome testing is now the gold standard for understanding why a loss occurred.
Progesterone support has a place — but timing and context matter. Blanket supplementation based on levels alone is not evidence-based.
Many widely used tests and treatments lack strong evidence and should not be ordered routinely without clinical indication.
Emotional support is a standard of care, not an optional add-on.
We're Here for the Whole Journey
If you've experienced recurrent pregnancy loss and want a thorough, individualized evaluation, Sun Valley Natural Medicine is here. We partner with your conventional care team and go deeper supporting your hormonal health, metabolic health, emotional wellbeing, and preconception vitality.
You deserve answers. Two losses is enough to start asking for them.
Sources:
American Society for Reproductive Medicine (ASRM), Recurrent Pregnancy Loss: A Committee Opinion, 2026. Fertility & Sterility, 2026.
This post is for educational purposes and does not constitute medical advice. Please consult with a qualified healthcare provider for personalized guidance.