In autism, regression refers to losing skills that were previously acquired. According to some research, up to 30 percent of children with autism experience some regression in language or social skills. This typically happens during the second year of life. Some children seem to be developing normally up to this point and then begin to regress. For example, some children begin talking and increasing their vocabulary and then either move backwards, using less and less words, or suddenly stop talking altogether.
Many parents report a "sudden" regression that seemingly occurs overnight. One day their child is talking and interacting; the next he doesn’t say a word or make eye contact, as if withdrawing into a shell. Some experts believe that most children, however, have a slow regression, which reaches a certain point before it is noticed. One study found that children begin to lose social skills at six months old, even though according to parent’s reporting, the average age of regression is between 13 and 18 months old. Because children develop at different rates and usually skills are developed or lost over a period of time, it is hard to pinpoint exactly when a child gained or lost a skill. Studies show that anywhere between 20 percent and 50 percent of children with autism have some regression of skills.
However, some experts believe this number is low and the early signs of autism are simply missed. For example, a report by the Hanen Centre states, "looking back at the home videotapes of young children with autism, some early symptoms have become apparent."  As parents, it is important to know the warning signs for autism and talk with your doctor. The following are some typical development signs:
Babbling - babies usually make babbling sounds prior to talking. By 12 months old, they look at caregivers when babbling and "take turns" talking with caregivers.
Pointing and making other gestures - By the age of 12 months, babies point to ask for items or to get someone’s attention, for example, they might point to a cracker or a cup of juice to indicate they want it. Other gestures, such as lifting their hands when they want to be picked up, waving "hi" or "bye-bye" and shaking their head "no" start appearing between 6 and 12 months of age. Along with pointing, by 12 months old your baby should also look in the direction that you point.
Showing or "sharing" items - By the time a child is 1 year old, he shows items to caregivers, such as showing a toy or other interesting item and expects a reaction from the caregiver.
Eye contact - by the age of 3 months old, most babies make eye contact with their caregivers.
Showing enjoyment - Smiling and laughing during interactions with caregivers begins as early as three months old. Babies usually seek out these types of interactions. Children with autism often show much more interest in objects than in people.
Repetitive actions - Most babies use some repetitive actions, such as flapping hands or spinning a car wheel, from time to time, however, children with autism exhibit repetitive actions much more frequently.
Using a variety of toys - Many households have a wide variety of toys for a baby to play with and your baby might spend time going from toy to toy. Children with autism often use only one or two toys or play with only a part of the toy, such as sitting for long lengths of time spinning the wheel on a toy car.
Imitating sounds and actions - By 12 months, children imitate sounds and gestures. They might clap when you clap or try to make the same sound. Children with autism often do not imitate their caregivers.
Responding to name - By one year old, children turn their heads when their name is said. Children with autism often do not respond to their name. Many parents may wonder if their child is hard of hearing.
By knowing the early warning signs of autism, you can be on the lookout for possible problems. If you do not notice the previous behaviors, talk with your pediatrician.
"Early Signs of Autism," Date Unknown, Lauren Lowry, The Hanen Centre
"IAN Research Findings: Regression," Date Unknown, Staff Writer, Autism Speaks
"Regression in Autism," 2010, Dr. Avril V. Brereton, Monash University
"Regression May Mark One-third of Autism Cases," 2012, Sept 27, Lindsay Borthwick, Simons Foundation Autism Research Initiative
Eileen Bailey is a freelance health writer. She is the author of What Went Right: Reframe Your Thinking for a Happier Now, Idiot’s Guide to Adult ADHD, Idiot’s Guide to Cognitive Behavioral Therapy, Essential Guide to Overcoming Obsessive Love, and Essential Guide to Asperger’s Syndrome. She can be found on Twitter @eileenmbailey and on Facebook at eileenmbailey.