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Romina Brignardello-Petersen vs. transgender people

Romina Brignardello-Petersen is a Canadian researcher and anti-transgender activist. From 2021 to 2024, Brignardello-Petersen received funding from anti-transgender hate group Society for Evidence-Based Gender Medicine (SEGM) and from an anti-trans project initiated in the state of Florida.

Brignardello-Petersen is closely associated with Gordon Guyatt and was recruited to support anti-trans FUD propaganda that claims trans healthcare is based on “low quality evidence.”

Brignardello-Petersen was co-author of a 2022 Florida report used as a pretext for banning coverage of trans healthcare. That report was then used to shape the UK’s Cass Review and the Trump Administration’s 2025 US HHS review, both also used as pretexts to ban gender affirming care for minors.

Background

Romina Brignardello-Petersen earned a dentistry degree from Universidad de Chile in 2007, as well as a master’s degree in 2014. Brignardello-Petersen also attended University of Toronto, earning a master’s degree in 2012 and doctorate in 2016.

Brignardello-Petersen was a lecturer at Universidad de Chile from 2008 to 2018. Starting in 2016, Brignardello-Petersen worked at McMaster University as a research fellow from 2016 to 2018, as assistant professor from 2018 to 2023, and as an associate professor since 2023.

Brignardello-Petersen included this biography in the 2022 Florida report:

“Dr. Romina Brignardello-Petersen: Assistant Professor at the Department of Health Research Methods, Evidence, and Impact, at McMaster University. Dr. Brignardello-Petersen obtained a DDS degree (University of Chile) in 2007, an MSc degree in Clinical Epidemiology and Health Care Research (University of Toronto) in 2012, and MSc in Biostatistics (University of Chile) in 2015, and a PhD inClinical Epidemiology and Health Care Research (University of Toronto) in 2016. Dr. Brignardello-Petersen has worked in evidence synthesis projects since 2010, and her research has focused on the methodology for the development of Systematic Reviews and Clinical Practice Guidelines since 2012.Through January 2022, she has published 122 peer reviewed scientific articles (24 as a first author and 9as a senior author). Dr. Brignardello-Petersen has acted as a research methodologist for several groupsand organizations, including the World Health Organization, the Pan-American Health Organization, the American Society of Hematologists, the American College of Rheumatology, and the Society for Evidence Based Gender Medicine, among others. Her research program has been awarded over $2M CAD from the Canadian Institutes for Health Research. Dr. Brignardello-Petersen has no lived experience as a person or family member of a person with gender dysphoria, and her research interests are not in this area.”

2022 Florida Department of Health report

Florida has long been one of the most hostile US states regarding the rights of trans and gender diverse people. Using slogans like “working together to protect our children” and “let kids be kids,” the state undertook an effort to eliminate gender affirming care for minors.

According to the Miami Herald, Brignardello-Petersen was the highest-paid consultant on the project:

Romina Brignardello-Petersen, a Canadian researcher, has collected $34,800, according to a state payment database, making her the highest paid consultant so far. Brignardello-Petersen previously did work for for the Society for Evidence Based Gender Medicine. A group of scientists from Yale University, in a public response critiquing Florida’s report, called that society an “activist group that opposes standard medical care for gender dysphoria.”

On April 20, 2022, the Florida Department of Health issued guidance related to gender affirming care for minors. The Secretary of the Florida Agency for Health Care Administration (AHCA) requested that Florida’s Medicaid program review “whether treatments are consistent with widely accepted professional medical standards.” AHCA commissioned five reports as a pretext for banning coverage of gender affirming care. The authors are:

The June 2, 2022 AHCA report found that “several services for the treatment of gender dysphoria – i.e., sex reassignment surgery, cross-sex hormones, and puberty blockers – are not consistent with widely accepted professional medical standards and are experimental and investigational with the potential for harmful long term affects.”

On July 8, 2022, Yale University pediatrician Meredithe McNamara and colleagues released â€śA Critical Review of the June 2022 Florida Medicaid Report on the Medical Treatment of Gender Dysphoria.” In it, they discuss the undisclosed conflict of interest:

The linchpin of the June 2 Report is the analysis by Brignardello-Petersen and Wiercioch (the “BPW document”), provided as Attachment C, which purports to be a comprehensive review of the scientific literature on medical treatment for gender dysphoria but, in fact, is extremely narrow in scope and so flawed in its analysis that it merits no scientific weight.

Romina Brignardello-Petersen is one of two authors of the document provided as Attachment C to the June 2 Report. Although Brignardello-Petersen claims to have no research interests in medical care for transgender youth,25 she has conducted research for the Society for Evidence-Based Gender Medicine (“SEGM”). 26 Although SEGM claims to be an international medical society, it is actually an activist group that opposes standard medical care for gender dysphoria. The SEGM has no publications or conferences and seems to consist solely of a website created by a small group of people with limited or no scientific credentials or clinical experience. The site presents a cherry-picked collection of studies and narrative content that is full of scientific errors. 27

26. Like the van Meter and Cantor attachments, the BPW document provides no express statement of conflicts of interest. The BPW document does offer a statement of “credentials and expertise,” in which she declares that “her research interests are not in this area,” meaning apparently research on medical care for gender dysphoria.

27. For one example of the purported research that Brignardello-Petersen apparently assisted in, see Alison Clayton et al., Commentary: the Signal and the Noise – Questioning the Benefits of Puberty Blockers for Youth with Gender Dysphoria – A Commentary on Rew et al. (2021), Child and Adolescent Mental Health, Dec. 22, 2021, at https://acamh.onlinelibrary.wiley.com/doi/10.1111/camh.12533. In the “Acknowledgements” section, the authors state, “We would also like to thank the Society for Evidence-based Gender Medicine (SEGM) for providing access to several experts who helped shape this commentary and ensure its accuracy. Specifically, we would like to thank Dr. Romina Brignardello Petersen [sic] for contributing her methodological expertise.”

“Low-quality evidence”

Federal judge Sarah E. Geraghty rejected these claims in a 2023 Georgia case where anti-trans activists Paul Hruz, Michael Laidlaw, and James Cantor testified against Yale University professor of pediatrics Meredithe McNamara:

The undisputed record shows that clinical medical decision-making, including in pediatric or adolescent medicine, often is not guided by evidence that would qualify as “high quality” on the scales used by Defendants’ experts. 30 (Doc. 70-1, McNamara Decl. ¶¶ 23–28; Tr. 74:11–75:1 (McNamara Testimony); Tr. 133:614 (Hruz Testimony).) In fact, the record shows that less than 15 percent of medical treatments are supported by “high-quality evidence,” or in other words that 85 percent of evidence that guides clinical care, across all areas of medicine, would be classified as “low-quality” under the scale used by Defendants’ experts. (Doc. 70-1, McNamara Decl. ¶ 25; Tr. 74:11–75:1.) Defendants do not refute Dr. McNamara’s testimony on this point, and indeed they “concede” that “low-quality” evidence “can be considered.” 31 [emphasis mine]

Geraghty also noted the obvious biases of Hruz, Laidlaw and Cantor:

Defendants’ experts’ insistence on a very high threshold of evidence in the context of claims about hormone therapy’s safety and benefits, and on the other hand their tolerance of a much lower threshold of evidence for claims about its risks, the likelihood of desistance and/or regret, and their notions about the ideological bias of a medical establishment that largely disagrees with them. That is cause for some concern about the weight to be assigned to their views, although the Court does not doubt that those they express are genuinely held.

(“Dr. [Paul] Hruz fended and parried questions and generally testified as a deeply biased advocate, not as an expert sharing relevant evidence-based information and opinions. I do not credit his testimony.”); Eknes-Tucker v. Marshall, 603 F. Supp. 3d 1131, 1142–43 (M.D. Ala. 2022) (explaining that the court gave Dr. James Cantor’s “testimony regarding the treatment of gender dysphoria in minors very little weight”); C. P. by & through Pritchard v. Blue Cross Blue Shield of Illinois, No. 3:20-CV-06145-RJB, 2022 WL 17092846, at *4 (W.D. Wash. Nov. 21, 2022) (noting that it was a “close question” as to whether Dr. Michael Laidlaw was qualified to testify about the medical necessity of gender-affirming care because he has treated only two patients with gender dysphoria and has done no original research on gender identity).

2023 SEGM conference

In 2023, SEGM held a conference in New York City. Gordon Guyatt was a featured speaker along with Romina Brignardello-Petersen, Ivan D. Florez, and Dena Zeraatkar.

2025 statement

In 2025, student activists at McMaster University began a campaign to get Brignardello-Petersen to acknowledge that the SEGM-McMaster research partnership “utilized GRADE to lend credibility to pseudoscience that opposes gender affirming care.” In June, members confronted Guyatt and Brignardello-Petersen, who both quickly left without commenting.

In August 2025, after Guyatt’s work had been cited extensively as a pretext to ban gender affirming care for minors, Guyatt stated, “Formerly, I thought my job ended with conducting and reporting high quality research. I now realize I have an additional responsibility to address how my work is used.”

Guyatt and team released a statement:

Members and allies of 2SLGBTQIA+ communities have raised concerns about recent systematic reviews related to gender-affirming care. These concerns center on the funding source, and specifically on the potential for the research to be misused to harm trans youth and to deny gender-affirming care. […]

In contrast to the way findings and presentation of our systematic reviews have been misrepresented and misinterpreted, they in fact show that, like the majority of what we do as physicians, the outcomes of specific aspects of care for transgender patients remain uncertain. The appropriate response to such uncertainty is shared decision-making that fully respects the autonomy of the individuals involved. Therefore, we have prepared the following letter related to our SEGM-sponsored systematic reviews: 

It is profoundly misguided to cast health care based on low-certainty evidence as bad care or as care driven by ideology, and low-certainty evidence as bad science. Many of the interventions we offer are based on low certainty evidence, and enlightened individuals often legitimately and wisely choose such interventions. Thus, forbidding delivery of gender-affirming care and limiting medical management options on the basis of low certainty evidence is a clear violation of the principles of evidence-based shared decision-making and is unconscionable. The appropriate use of our work is in ensuring patients receive needed care and in helping TGD patients and their clinicians in decision making. 

We acknowledge concerns that have been raised.1 Our research agreement with SEGM ended in 2024. When the agreement started in 2021, the organization appeared to us as non-trans, cis-gender researchers to be legitimately evidence-based.  

We will no longer accept funding from SEGM. As recommended by community advocates, we have also personally made a donation to Egale Canada’s legal and justice work, noting their litigation efforts aimed at preventing the denial of medically necessary care for gender-diverse youth. 

Selected publications by Brignardello-Petersen

Miroshnychenko, A., Ibrahim, S., Roldan, Y., Kulatunga-Moruzi, C., Montante, S., Couban, R., Guyatt, G., & Brignardello-Petersen, R. (2025). Gender affirming hormone therapy for individuals with gender dysphoria aged <26 years: a systematic review and meta-analysis. Archives of Disease in Childhood, 110(6), 437–445. https://doi.org/10.1136/archdischild-2024-327921

  • Funding This work was commissioned by the Society for Evidence based Gender Medicine (SEGM), the sponsor, and McMaster University. This systematic review is part of a large research project funded through a research agreement between SEGM, the sponsor and McMaster University. None of the team members received financial compensation directly from SEGM to conduct this systematic review and meta-analysis.
  • Competing interests The funding and disclosures statement includes all of the authors of this manuscript as well as all of the authors of the published protocol. The authors of the published protocol included representatives from the sponsor who participated only in the development of the systematic review question. None of the team members received financial compensation directly from the Society for Evidence based Gender Medicine (SEGM) to conduct this systematic review and meta-analysis. Financial conflicts of interest (manuscript authors): RB-P and AM provided methodological expertise for the SEGM initiative to summarise and appraise the quality of publications related to gender medicine for the SEGM online platform, and for this work they received financial compensation from SEGM. This work was completely independent from the systematic review and meta-analysis. Financial conflicts of interest (as reported by the protocol authors who were not part of the evidence synthesis team at the time of their participation in the generation of the question): E Abbruzzese is a contributing author for the SEGM online platform and received financial compensation from SEGM. William Malone’s fee for publishing a research article as ‘open access’ was compensated by SEGM. Other disclosures (manuscript authors): CK-M has expressed opinions on recommendations for gender affirming care for transgender and gender diverse youth in the Journal of Pediatrics and Child Health. This opinion piece was published after this systematic review was submitted for publication, and the content of this systematic review did not change. Other disclosures (as reported by the protocol authors who were not part of the evidence synthesis team at the time of their participation in the generation of the question): William Malone is a board member of SEGM. William Malone has expressed opinions about gender affirmation interventions for adolescents and young adults in the Journal of Clinical Endocrinology and Metabolism, The Lancet, Child and Adolescent Health and Medscape.

Miroshnychenko A, Roldan Y, Ibrahim S, Kulatunga-Moruzi C, Montante S, Couban R, Guyatt G, Brignardello-Petersen R (2025). Puberty blockers for gender dysphoria in youth: A systematic review and meta-analysis. Archives of Disease in Childhood, 110(6), 429–436.

Financial conflicts of interest (manuscript authors):

Direct financial conflicts of interest: Dr. Romina Brignardello-Petersen and Anna Miroshnychenko provided methodological expertise for the SEGM initiative to summarize and appraise the quality of publications related to gender medicine for the SEGM online platform, and for this work they received financial compensation from SEGM. This work was completely independent from the systematic review and meta-analysis. Indirect financial conflicts of interest: Manuscript authors do not have indirect financial conflicts of interest.

2. Financial conflicts of interest (as reported by the protocol authors who were not part of the evidence synthesis team at the time of their participation in the generation of the question):

Direct financial conflicts of interest: AUTHOR ACCEPTED MANUSCRIPT 24 E. Abbruzzese is a contributing author for the Society for Evidence-based Gender Medicine online platform and received financial compensation from SEGM. Indirect financial conflicts of interest: Dr. William Malone’s fee for publishing a research article as “open access” was compensated by SEGM.

3. Other disclosures (manuscript authors): Expressed opinions: Dr. Chan Kulatunga-Moruzi has expressed opinions on recommendations for gender-affirming care for transgender and gender-diverse youth in the Journal of Pediatrics and Child Health. This opinion piece was published after this systematic review was submitted for publication, and the content of this systematic review did not change.

3. Other disclosures (as reported by the protocol authors who were not part of the evidence synthesis team at the time of their participation in the generation of the question): Affiliations: Dr. William Malone is a board member of SEGM. Expressed opinions: Dr. William Malone has expressed opinions about gender affirmation interventions for adolescents and young adults in The Journal of Clinical Endocrinology and Metabolism, The Lancet, Child and Adolescent Health, and Medscape.

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