For Clinicians

Guidelines and developments.

Guideline changes and trial results that alter what we can offer, with guidelines and trial findings marked separately so it is clear which is which.

Society Guidelines

United States

American Society for Reproductive Medicine (ASRM)
American College of Obstetricians and Gynecologists (ACOG)
US Preventive Services Task Force (USPSTF)
American Thyroid Association (ATA)
American Diabetes Association (ADA)
American College of Medical Genetics and Genomics (ACMG)
Society for Maternal-Fetal Medicine (SMFM)

International

European Society of Human Reproduction and Embryology (ESHRE)
National Institute for Health and Care Excellence (NICE, United Kingdom)
Royal College of Obstetricians and Gynaecologists (RCOG, United Kingdom)
Society of Obstetricians and Gynaecologists of Canada (SOGC)
Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG)
What has changed recently

Updates to Guidelines

Recurrent Pregnancy LossGuidelineASRM 2026 Committee Opinion: Recurrent Pregnancy LossDefines recurrent pregnancy loss as two or more losses, which need not be consecutive, and counts pregnancies confirmed by hCG alone.Narrows the workup: chromosome analysis of miscarriage tissue from the second loss, parental karyotyping only in defined circumstances, and no routine thrombophilia, thyroid antibody, immune, or microbiome testing. Replaces the 2012 opinion.Read ↗ICSIGuidelineASRM 2026 Committee Opinion: ICSI for Non–Male Factor IndicationsRoutine ICSI is not recommended in the absence of male factor infertility or prior fertilization failure.Cites no improvement in live birth rates, added cost and laboratory complexity, and population data associating non-indicated ICSI with poorer outcomes. Scoped to non–male factor indications only.Read ↗Thyroid DiseaseGuidelineATA 2026 Guidelines: Thyroid Disease in Preconception, Pregnancy, and PostpartumLevothyroxine should not be offered to euthyroid women who are thyroid antibody positive, and antibody status no longer guides treatment of subclinical hypothyroidism.Both positions reverse the 2017 guideline. Timing now decides subclinical treatment: it may be considered in the first trimester but should not be offered after it. New-onset overt hypothyroidism with a TSH below 6 mU/L warrants confirmatory retesting first, since fewer than half of these abnormalities persist. Universal screening is still not recommended, but TSH testing should be performed in all non-pregnant women presenting with infertility or recurrent miscarriage.Read ↗

Recent Publications

Bacterial VaginosisTrial resultVIBRANT: Vaginal L. crispatus live biotherapeutics in bacterial vaginosisPhase 1: multi-strain L. crispatus products were safe and colonized 66% of recipients following metronidazole treatment for bacterial vaginosis.Safety and colonization study. No pregnancy, miscarriage, or live-birth outcomes were measured, and no efficacy claim against recurrence is supported at this phase.Read ↗Bacterial VaginosisTrial resultStepUP: Male-partner treatment to prevent bacterial vaginosis recurrenceTreating male partners alongside women reduced bacterial vaginosis recurrence at 12 weeks (35% vs 63% of couples).Open-label, 164 couples, stopped early by the data monitoring committee for benefit, which tends to inflate effect size. No pregnancy outcomes; relevance to loss is indirect, through recurrence.Read ↗ProgesteroneTrial resultPRISM: Progesterone for bleeding in early pregnancyProgesterone did not significantly increase live births overall: 75% vs 72% (RR 1.03, 95% CI 1.00–1.07, P=0.08).A pre-specified subgroup with three or more previous miscarriages did show higher live birth (72% vs 57%; RR 1.28, 95% CI 1.08–1.51). That is a subgroup finding from a trial that missed its primary endpoint, and should be read as such.Read ↗Chronic EndometritisTrial resultCERM: Preconception doxycycline for chronic endometritis in recurrent miscarriageDoxycycline did not improve live births (RR 1.02, credible interval 0.85–1.21); the authors advise against routine screening and treatment for chronic endometritis in recurrent miscarriage.Reported as an ESHRE 2025 conference abstract, not yet a peer-reviewed paper; intervals are Bayesian credible intervals. Follow-on work is expected to test microbiome repair with probiotics rather than antibiotics alone, no such trial in recurrent loss is currently registered or published.Read ↗