Fact check: How do professional sports leagues verify athlete eligibility based on biological sex?

1. Summary of the results

Based on the analyses provided, professional sports leagues are implementing increasingly standardized approaches to verify athlete eligibility based on biological sex, with genetic testing emerging as the primary method.

World Boxing has introduced the most comprehensive policy, mandating PCR genetic tests for all boxers to detect the presence of the SRY gene on the Y chromosome ^[1]. This policy applies to athletes over 18 and determines male category eligibility based on Y chromosome genetic material or disorders of sexual development (DSD) with male androgenization ^[2]. The policy specifically affects high-profile athletes, including Olympic boxing champion Imane Khelif, who must undergo genetic sex screening to participate in upcoming events ^[3].

World Athletics has similarly adopted mandatory biological sex testing for female competitions, utilizing non-invasive cheek swab tests or dry blood tests to detect the SRY gene ^{[4] [5]}. These organizations justify these measures as necessary to "ensure a level playing field," "protect the integrity of female sports," and "prevent unfair performance advantages" ^{[1] [4] [5]}.

2. Missing context/alternative viewpoints

The analyses reveal significant gaps in coverage of how other major professional sports leagues handle this issue. The sources focus heavily on World Boxing and World Athletics but provide no information about policies in major professional leagues like the NFL, NBA, MLB, NHL, or FIFA ^{[6] [7] [8]}.

The analyses also lack discussion of alternative verification methods beyond genetic testing. While high school sports require various eligibility criteria including "physical examination" among other requirements ^[6], the analyses don't explore whether professional leagues use medical examinations, hormone level testing, or other biological markers.

Missing perspectives include:

• Views from athletes who may be affected by these policies
• Medical professionals' opinions on the accuracy and ethics of genetic testing
• Legal challenges or human rights concerns
• Cost and accessibility issues of implementing genetic testing across all professional sports

The analyses also don't address how these policies handle intersex conditions or disorders of sexual development beyond the brief mention in World Boxing's policy ^[2].

3. Potential misinformation/bias in the original statement

The original question itself doesn't contain explicit misinformation, but it assumes a uniform approach across professional sports leagues that the analyses don't support. The evidence shows that verification methods are not standardized across all professional sports - only specific organizations like World Boxing and World Athletics have implemented comprehensive genetic testing policies ^{[1] [4] [5] [2] [3]}.

The question also implies that all professional sports leagues actively verify biological sex, but the analyses suggest this is a recent development rather than an established practice. The dates show these policies were introduced in 2025, indicating this is an emerging trend rather than standard practice ^{[1] [4] [5] [2] [3]}.

Additionally, the framing focuses solely on "biological sex" without acknowledging the complexity of sex determination that the analyses hint at, particularly regarding DSDs and genetic variations that these new testing protocols are designed to address ^[2].