HHS’ New Definitions of ‘Sex,’ ‘Man,’ and ‘Woman’ Spark Controversy, Criticized for Defying Science

HHS’ New Definitions of ‘Sex,’ ‘Man,’ and ‘Woman’ Spark Controversy, Criticized for Defying Science

The U.S. Department of Health and Human Services (HHS), under Secretary Robert F. Kennedy Jr., has introduced new guidelines defining sex in binary terms—male and female—excluding gender identity. This controversial decision, made on February 19, 2025, has sparked backlash from experts and advocates who argue it contradicts established scientific understanding and could harm gender-diverse and intersex individuals.

The New Guidelines

The HHS guidelines define “sex” strictly as a biological classification, labeling “male” and “female” based on reproductive functions—sperm production for males and egg production for females. The definitions include terms like “woman” as an adult human female and “man” as an adult human male, excluding any reference to gender identity or variations in sex characteristics beyond these two categories.

These definitions align with the Trump administration's stance on "gender ideology," which advocates for the recognition of only two sexes—male and female—while rejecting broader, more inclusive approaches to gender and sex used by medical professionals. The new rules also promote policies like restricting transgender individuals from competing in women’s sports and limiting access to gender-affirming care for minors.

Ignoring Scientific and Medical Realities

Critics argue that these definitions ignore the complex realities of biological sex and gender identity. “The claim that sex is an ‘immutable biological classification’ goes against scientific understanding,” said Dr. Ray Haider, a psychiatrist at Mindpath Health. Haider pointed out that biological sex can vary across multiple dimensions, including chromosomal sex, gonadal sex, and external genitalia. People with intersex conditions, such as androgen insensitivity syndrome, may not fit neatly into the binary categories of male or female, yet their existence is excluded under the new guidelines.

Dr. Anne-Marie Amies Oelschlager, an expert in obstetrics and gynecology at the University of Washington, emphasized that sex differentiation is a highly complex process influenced by hundreds of genes and hormonal influences. She noted that many people are born with variations in sex characteristics that cannot be categorized simply as male or female, such as those with XXY chromosomes or ovotestes, which include both ovarian and testicular tissue.

Intersex traits, affecting an estimated 1.7% of the population, are largely ignored by the new definitions, leading to concerns about the potential for further marginalization of these individuals.

Harm to Transgender and Gender-Diverse People

Experts also warn that the new definitions could worsen the mental and physical health of transgender and gender-diverse individuals. Dr. Haider explained that the erasure of these identities could exacerbate the psychological toll on individuals already facing discrimination. Studies have shown that transgender people, especially youth, experience increased rates of depression, anxiety, and suicidal thoughts when their identities are invalidated by policies and societal norms.

Access to gender-affirming care, including hormone therapy and surgeries, is crucial for many transgender individuals to alleviate gender dysphoria. The HHS guidelines, along with other recent state and federal policies limiting such care, may disrupt vital treatments, leading to long-term health consequences such as osteoporosis, cardiovascular disease, and cognitive decline.

Dr. Amies Oelschlager echoed these concerns, stating that the fear and sadness among gender-diverse youth are compounded by such regressive policies. Parents of transgender and nonbinary children are also expressing anxiety, knowing their children are vulnerable to increased discrimination and reduced access to appropriate healthcare.

Public Health Concerns and the Broader Impact

Beyond the immediate harm to transgender and intersex individuals, critics argue that the HHS guidelines threaten public health progress by narrowing the scope of sex and gender classifications in research and medicine. Without recognition of gender diversity and intersex conditions, healthcare providers may fail to offer appropriate treatments for these populations, perpetuating health disparities and neglecting critical needs.

In contrast to the Biden administration’s efforts to promote inclusivity and address the needs of gender-diverse people, the new HHS guidelines represent a retreat from these goals, pushing federal policies further in the direction of gender binary classification.

The Road Ahead

The decision to implement these new guidelines has led to significant concerns among public health experts, LGBTQI+ advocates, and medical organizations. The move aligns with previous executive orders from the Trump administration that sought to limit gender-inclusive language and restrict healthcare rights for transgender individuals. As legal challenges to these policies unfold, experts warn of the lasting impact on the mental and physical well-being of vulnerable populations.

For now, the HHS guidelines remain in effect, but the debate over their scientific accuracy and the harm they may cause is likely to continue in the months ahead.