Glossary /
Assigned sex at birth
Formal出生指派性别 · AFAB · AMAB · assigned gender
The male-or-female call recorded at birth from visible anatomy — "assigned" because someone else made it.
Assigned sex at birth is the determination — male or female — that medical staff make and record when a baby is born, based on external sex characteristics. The word “assigned” is doing the important work: it reminds us this was a judgment someone else made at the moment of your birth. Most of the time it matches the person’s later gender identity (cisgender); sometimes it doesn’t (transgender).
English commonly abbreviates: AFAB (assigned female at birth) and AMAB (assigned male at birth). When you need to talk about someone’s body or upbringing without misgendering them, this phrasing is both more accurate and more respectful than “used to be a man/woman.”
Register note: current in formal, medical, and community contexts alike. In everyday conversation you don’t need to be technical about it — the point is to avoid identity-denying phrases like “but he’s really a man.”
Common mistranslation: rendering this concept as “biological sex” (Chinese 生理性别). That phrase implies the body offers one simple, binary fact that is more “real” than identity — but sex characteristics are themselves multidimensional and varied. “Assigned sex at birth” describes an act of registration, which is exactly what happened.