Developmental disorders of the female reproductive tract are abnormalities that occur in the reproductive organs a female fetus.

With the union of a sperm and an ovum (egg), the embryo acquires chromosomes that determine the sex of the fetus (XX=female, XY=male). During the first six weeks, the sex of the fetus is not distinguishable.

At about six weeks gestation, ovaries develop in those with two X chromosomes, and testes develop in those with an X and a Y chromosome. Development of the remaining genital organs occurs through the first 12 weeks of pregnancy.

Abnormalities may be caused by genetic defects and/or hormonal problems in the uterus. If a boy's testes do not start producing testosterone when they should or if there are other abnormalities, the child may not develop a penis and may appear to be a girl even though the child has XY chromosomes. There may be other abnormalities of the female reproductive system, such as a vagina but no uterus, in such cases.

In other cases, an XX girl may be exposed to high levels of testosterone in the womb, which may cause the development of an enlarged clitoris or a small penis.

In another type of defect of the female reproductive tract, there is an extra X or Y chromosome, which causes similar problems in sexual differentiation. Such children may have genitalia that are "in between" or resemble parts of those of either sex.

Such infants are said to have ambiguous genitalia, which may make it difficult to determine at birth whether the child is a boy or a girl.