Purpose or Case Report: Background: Disorders of sexual development (DSD) resulting in ambiguous genitalia are a rare spectrum of anomalies that have the potential to be diagnosed prenatally using a combination of genetic testing and imaging. The incidence of prenatal detection is rising with the increased use of noninvasive prenatal testing, which can reveal discordance between genotype and phenotype.

Sonographic and MR imaging contribute to prenatal assessment of disorders of DSD and may narrow the differential diagnosis and facilitate prenatal testing and postnatal evaluation.

The goals of this exhibit are:
1. Review imaging features of normal prenatal male and female genitalia.
2. Review imaging patterns of ambiguous genitalia.
3. Discuss changes in appearance with various pathologies, providing imaging examples.
4. Review different categories of disorders of sexual differentiation and see how imaging may narrow the differential diagnosis.
Methods & Materials: Fetal ultrasound and MR studies at our institute were reviewed retrospectively with selected representative cases chosen to illustrate technical aspects and to demonstrate the imaging features in cases of ambiguous genitalia. Correlation was made with NIPT, amniocentesis, and CVS results in conjunction with follow up radiology studies, and clinical or surgical outcomes.

Categorical disorders of sexual development, such as 46 XX, 46 XY, ovotesticular DSD and sex chromosome will be described.
Results: Prenatal findings in the normal fetus and in disorders of sexual development fetal will be illustrated with postnatal correlation.
Conclusions: DSD is a complex group of disorders requiring an understanding of anatomical variations of genitalia and the diseases within each group. US and MR contribute to the prenatal detection of DSD, help narrow the differential diagnosis and help direct prenatal and postnatal genetic testing and imaging.