Atypical Genitalia (Differences of Sex Development)

Sex development occurs in stages. Babies have many opportunities to develop along paths that are not the typical one male or female phenotype. When sex development follows a less common path, the result is a difference of sex development (DSD*). Knowing at what point the path changed helps us provide appropriate medical care. 

*DSD is a term in evolution. Commonly used terms to describe DSD conditions include difference of sex development, disorder of sex development and intersex.

Differences of sex development occur more frequently than most people realize. An estimated one in 4,500 children has such a condition. While many times, these differences are found at birth, some are not found until later in life, even though these conditions are present since early in development.

Human development is a complicated process. Slight differences in the usual process can result in a difference of sex development. Because these developmental differences occur before birth, they are called congenital.

Three Key Times for DSD to Occur in Development

At Fertilization

When the egg from the mother meets the sperm from the father, the child’s chromosomal makeup is determined. The mother typically gives an X chromosome and the father either an X or Y chromosome. Usually, an XX individual is a girl and an XY is a boy. Sometimes, however, a child gets an extra chromosome from a parent or a chromosome is absent, resulting in XXY, XO or XYY. These differences lead to a DSD.

In Early Fetal Development

When a fetus is just forming in the mother’s uterus, an organ is present that we call the gonad. It is identical in girls and boys until midway through the second month of pregnancy. At that time, certain signals direct the gonad to develop into an ovary or a testicle. Any abnormality in these signals can lead to an abnormal gonad. For example, it may contain both ovarian and testicular tissue or may not produce hormones properly.

In Later Fetal Development

Further development leads to a child having organs — typically, a uterus, fallopian tubes, clitoris and labia in a girl or the seminal vesicles, penis and scrotum in a boy. At first, every fetus has the potential to develop either set of organs on the inside or outside. After the gonad becomes an ovary or a testicle, it makes hormones that help the body determine which type of structures to develop on the inside and outside. Variations in this development can lead to a range of abnormalities. For example:

  • A structure that may look like a small penis or a large clitoris
  • A penis with the opening at the base instead of the tip and no testes in the scrotum
  • An individual with testicles and male internal structures, but who looks female on the outside

Tests and exams help us know as precisely as possible what caused the difference. Understanding why the DSD occurred helps us to determine the best treatment for the child. Also, we use this information to help the family understand what to expect for their child. The precise cause cannot, however, always be determined.

A DSD brings a complex set of physical, medical and emotional challenges affecting both the child and parents. The approach to care at Lurie Children’s is to address all of these needs in a sensitive manner. Our goal is a happy, healthy child and the best possible future for each individual in our care.


A diagnosis of a DSD can be overwhelming, and the team at Lurie Children’s is committed to providing supportive and compassionate care for your family. Our specialists are dedicated to working with patients and families to understand patient’s hopes and goals for the future.

As children grow from infancy to adolescence to adulthood, their medical and social needs evolve. The Sex Development Program’s multidisciplinary staff collaborates with patients as they transition into adolescents to ensure that they have accurate information and continued access to supportive and comprehensive care.

Detection & Diagnosis

A DSD can be detected and diagnosed for a variety of reasons and at different times in a patient’s life.


Competent, collaborative multi-disciplinary care assures the best possible outcome for a child with a DSD. Our team at Lurie Children’s includes specialists in in pediatric endocrinology, child psychology, urology, pediatric surgery, genetic counseling, social work, nursing and medical ethics, all of whom have specific expertise in gender and sex development.

Specialists & Experience

Our multidisciplinary staff is dedicated to evaluating and treating pediatric patients from infancy through adolescence. These specialists include:

  • Endocrinologists
  • Urologists
  • Clinical psychologists
  • Psychiatrists
  • Ethics consultants
  • Social workers


Meet all of our specialists

Make an Appointment

To find out more information about our program or to request an appointment, call 312.227.6203.


The medical and research team continues to actively pursue research studies aimed at better understanding DSD conditions and how to care for them. Our recent research focus has been fertility and experimental fertility preservation. Studies we have recently published demonstrate that fertility potential may be greater than previously thought for children with DSD (Finlayson, Journal of Urology, 2017) and that fertility is a common concern for parents making medical decisions on behalf of their children (Johnson, Journal of Pediatric Urology, 2017). 

Ongoing studies include:

  1. To understand patient perspectives regarding fertility and fertility preservation, we are currently recruiting patients age 13 years and older to participate in a research interview.
  2. We are actively recruiting patients (age 15+) and parents for a survey regarding the words used in clinic to describe various DSD conditions. A recent study published by Dr. Johnson showed that those in support groups tend to view current terminology negatively (Johnson, Journal of Pediatric Urology, 2017), but we are interested in learning the perspective of our general clinic population, who may or may not be in support groups.
  3. Our group is also participating in a multi-center, prospective study sponsored by the National Institutes of Health (NIH) studying psychosocial and surgical outcomes for infants and families seen in clinics such as ours. Longer-term follow-up is ongoing among patients and families already recruited for this study, and will begin recruitment of additional families  in fall 2018.


Many families also find significant support from trusted family members, friends, support groups, advocacy organizations and their religious support system. Below are resources with additional information: 

Get more information with these recommended books:

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