Children With Autism Have Elevated Levels of Steroid Hormones in the Womb

Researchers have discovered that children who later develop autism are exposed to elevated levels of steroid hormones (ie, testosterone, progesterone, and cortisol) in the womb.

The finding, published in the journal Molecular Psychiatry, may help explain why autism is more common in males than females, but should not be used to screen for the condition.

Simon Baron-Cohen, MD, and Michael Lombardo, MD, University of Cambridge, Cambridge, United Kingdom, and Bent Nørgaard-Pedersen, MD, Statens Serum Institute, Copenhagen, Denmark, and colleagues utilised approximately 19,500 amniotic fluid samples stored in a Danish biobank from individuals born between 1993 and 1999.

The fluid was collected when women chose to have an amniocentesis around 15 to 16 weeks of pregnancy. This coincides with a critical period for early brain development and sexual differentiation, and thus allows scientists access into this important window in fetal development.

The researchers identified amniotic fluid samples from 128 males later diagnosed with an autism spectrum condition and matched these up with information from a central register of all psychiatric diagnoses in Denmark.

Within the amniotic fluid the researchers looked at 4 key ‘sex steroid’ hormones that are each synthesised, step-by-step from the preceding one, in the ‘4 sex steroid’ pathway: progesterone, 17 alfa-hydroxy-progesterone, androstenedione, and testosterone. They also tested the steroid hormone cortisol that lies outside this pathway.

Autism is usually identified by the time a child is 30 months old. It is often discovered when parents become concerned that their child may be deaf, is not yet talking, resists cuddling, and avoids interaction with others.

Some of the early signs and symptoms which suggest a young child may need further evaluation for autism include:

no smiling by six months of age
no back and forth sharing of sounds, smiles or facial expressions by nine months
no babbling, pointing, reaching or waving by 12 months
no single words by 16 months
no two word phrases by 24 months
regression in development
any loss of speech, babbling or social skills

A preschool age child with "classic" autism is generally withdrawn, aloof, and fails to respond to other people. Many of these children will not even make eye contact. They may also engage in odd or ritualistic behaviors like rocking, hand flapping, or an obsessive need to maintain order.

Many children with autism do not speak at all. Those who do may speak in rhyme, have echolalia (repeating a person's words like an echo), refer to themselves as a "he" or "she," or use peculiar language.