Overview of Differences of Sex Development

The conditions are listed in a ‘logical’ way, following the various steps in the process of sex development. Use the main picture of the ‘Story of Sex Development’ to help you understand the many ways bodies can develop.

General Terms
Name Short Description

Estimated Numbers

Genital difference (also called 'ambiguous')  Genitalia that looks less typical and when it is not clear to an untrained health care professional whether baby is a boy or a girl and further investigations might be needed 1/4500-1/5500 
Clitoromegaly A girl with clitoromegaly is born with a clitoris that is larger than usual 1/10000

Undescended testes


A baby born with no testes in the scrotum 3/10 premature baby boys; in general 3/100 baby boys are born with at least one teste undescended
Hypospadias When the opening of the penis (the urethra) is not at the tip but along the bottom shaft of the penis. There is a huge range of how hypospadias can affect someone, e.g, mild (the opening is near the tip) or peno-scrotal (the opening at the base of the penis shaft) or anywhere in between.Only children born with peno-scrotal hypospadias would be supported and cared for in a difference of sex development context. 1/3000 boys