Possible causes in genetic females
Causes of ambiguous genitalia in a genetic female may include:

Congenital adrenal hyperplasia. Certain forms of this genetic condition cause the adrenal glands to make excess male hormones (androgens).
Prenatal exposure to male hormones. Certain drugs that contain male hormones or that stimulate production of male hormones in a pregnant woman can cause developing female genitals to become more masculine. A developing baby also may be exposed to excess male hormones if the mother has a disease or condition that causes hormone imbalance.
Tumors. Rarely, a tumor in the mother can produce male hormones.
Possible causes in genetic males
Causes of ambiguous genitalia in a genetic male may include:

Impaired testicle development. This may be due to genetic abnormalities or unknown causes.
Androgen insensitivity syndrome. In this condition, developing genital tissues don't respond normally to male hormones made by the testes.
Abnormalities with testes or testosterone. Various abnormalities can interfere with the testes' activity. This may include structural problems with the testes, problems with production of the male hormone testosterone or problems with cellular receptors that respond to testosterone.
5a-reductase deficiency. This enzyme defect impairs normal male hormone production.
Ambiguous genitalia can also be a feature of certain rare, complex syndromes that affect many organ systems.

Risk factors
Family history may play a role in the development of ambiguous genitalia, because many disorders of sex development result from genetic abnormalities that can be inherited. Possible risk factors for ambiguous genitalia include a family history of:

Unexplained deaths in early infancy
Infertility, absent menstrual periods or excess facial hair in females
Genital abnormalities
Abnormal physical development during puberty
Congenital adrenal hyperplasia, a group of inherited genetic disorders that affect the adrenal glands
If your family has a history of these risk factors, consider seeking medical advice before trying to conceive. You may also benefit from genetic counseling.

Complications
Complications of ambiguous genitalia may include:

Infertility. Whether people with ambiguous genitalia can have children depends on the specific diagnosis. For example, genetic females with congenital adrenal hyperplasia usually can get pregnant if they so choose.
Increased risk of certain cancers. Some disorders of sex development are associated with an increased risk of certain types of cancer.
https://www.mayoclinic.org/diseases-conditions/ambiguous-genitalia/symptoms-causes/syc-20369273