Developmental Regression
When your child loses skills they once had - what to do and why speed matters
What Happened
You have noticed that your child has lost skills they previously had. This is called developmental regression, and it is different from a developmental plateau (where a child pauses in gaining new skills but keeps the ones they have). Regression means a child could do something - say words, walk, make eye contact, use their hands purposefully - and now they can no longer do it. This is always worth investigating. The causes range from benign and temporary (such as stress or a new sibling) to conditions that require prompt medical attention. Regression does not automatically mean something devastating, but it does mean your child deserves a thorough evaluation without delay.
Key Facts
- Developmental regression means the loss of previously acquired skills - this is different from a child who is slow to gain new skills (delay) or who pauses in development (plateau).
- Regression can affect any domain: language (losing words), motor skills (losing the ability to walk or use hands), social skills (losing eye contact or interest in others), or self-care skills (losing toileting ability).
- Language regression between 15 and 24 months, especially loss of words combined with loss of social engagement, is one of the patterns seen in autism spectrum disorder. Early evaluation and intervention lead to better outcomes.
- In rare cases, regression can signal neurological conditions such as epileptic encephalopathy (like Landau-Kleffner syndrome), metabolic disorders, or neurodegenerative conditions. These are uncommon but treatable or manageable when caught early.
- Temporary and reversible regression can occur with major life stressors (new sibling, move, illness, trauma). This type of regression is usually mild and short-lived.
- Documentation is powerful. Your observations as a parent are critical clinical data. Write down what your child could do and when they stopped doing it.
What to Expect
- Your pediatrician should take a report of regression seriously and may refer you to a developmental pediatrician, pediatric neurologist, or both.
- A thorough evaluation may include developmental screening questionnaires, hearing and vision tests, blood work (metabolic and genetic panels), and possibly an EEG or brain MRI.
- The timeline for evaluation will depend on the type and severity of regression. Loss of motor skills or regression in multiple domains typically warrants urgent referral.
- You may hear the phrase "watchful waiting." If the regression is isolated, mild, and recent, a short observation period may be appropriate - but ask for a specific follow-up date and clear criteria for when to escalate.
- If autism spectrum disorder is suspected, an evaluation by a developmental specialist can often happen alongside other testing. Do not wait for one evaluation to finish before starting another.
When to Worry
- Loss of motor skills (can no longer sit, stand, walk, or use hands as before) is always urgent. Contact your pediatrician immediately or go to the emergency room.
- Loss of multiple types of skills at the same time (for example, words AND walking AND social engagement) requires immediate medical evaluation.
- Regression accompanied by seizures, unusual eye movements, or episodes of staring or unresponsiveness should be evaluated in the emergency department.
- Regression after a period of normal development beyond age 2–3 is less common and should be evaluated promptly by a specialist.
- If your pediatrician dismisses your concern about skill loss, advocate clearly: "My child used to do X, and now they cannot. I need this evaluated." You can request a referral or seek a second opinion.
Your Action Plan
- Document everything. Write down the specific skills your child has lost, approximately when they were last observed, and any changes in behavior, sleep, eating, or responsiveness. Include videos if possible - before-and-after comparisons are valuable to specialists.
- Call your pediatrician within 24–48 hours of noticing regression. Use the word "regression" explicitly: "My child has lost skills they previously had. I am seeing regression."
- Request referrals to a developmental pediatrician and/or pediatric neurologist. If your pediatrician suggests waiting more than 2–4 weeks to refer, ask why and whether an earlier evaluation is possible.
- Contact your state's Early Intervention program (for children under 3) or your school district (for children 3 and older) for a free developmental evaluation. You do not need a doctor's referral for this, and you can pursue it at the same time as medical evaluation.
- If your child is losing language and social skills, request an autism-specific evaluation. Early identification and early behavioral intervention (such as ABA or developmental approaches) produce the best outcomes.
- Keep a brief daily log of skills you observe - words used, physical abilities, social behaviors. This ongoing record will help specialists see patterns.
- Take care of yourself. Watching your child lose skills is frightening. Reach out to other parents through trusted organizations (such as your local Parent Training and Information Center) and consider support for your own emotional wellbeing.
Sources
Lipkin PH, Macias MM; Council on Children with Disabilities, Section on Developmental and Behavioral Pediatrics. Promoting optimal development: Identifying infants and young children with developmental disorders through developmental surveillance and screening. Pediatrics. 2020;145(1):e20193449.
Learn the Signs. Act Early. Developmental Milestones.
Hyman SL, Levy SE, Myers SM; Council on Children with Disabilities, Section on Developmental and Behavioral Pediatrics. Identification, evaluation, and management of children with autism spectrum disorder. Pediatrics. 2020;145(1):e20193447.