How should we make sense of pregnancy discrimination as an issue of gender equality? In a striking 1974 decision, Geduldig v. Aiello, the US Supreme Court has answered that we simply cannot. Pregnancy discrimination does not constitute a form of sex discrimination prohibited by law, the 6–3 decision claims, because differential treatment based on pregnancy draws only a gender-neutral line between “pregnant women” and “nonpregnant persons,” not the gender line between women and men. While courts have since invoked Geduldig to curtail both reproductive and transgender rights, the prevailing feminist response to this line of cases is still to double down on an awkwardly cissexist conception of gender, finding the sex discrimination in the “direct” way that pregnancy is thought to connect to womanhood. The failure of that prevailing feminist response, legitimizing rather than challenging biological essentialism in legal analysis and public discourse, epitomizes a broader failure of feminist analysis and intersectional solidarity: It fails to face up to the political and social problem that is pregnancy discrimination for either cis or trans people. This essay offers a trans feminist alternative. I argue that pregnancy discrimination is discrimination on the basis of sex, within the legally relevant meaning of that phrase, not because pregnancy is in one way or another distinctive to women as a gender category but because pregnant persons make up a gender category of their own. On my analysis, pregnancy discrimination comes out as a form of sex discrimination directly and immediately, not by way of womanhood.