Here’s what the new CDC milestones mean for parents.

There are so many different ways to be a parent, but there is one thing that’s always true: we all want the best for our little ones. While language development before the age of two is related to school performance—with knock-on effects for socio-emotional, cognitive and behavioral functioning, you don’t need to be a scientist to get the sense that speech and language development is important.

The rapid changes in your child’s language ability and vocabulary during this period mean that you need to know what to look out for and when to act if you suspect something might be wrong. For nearly half of parents, their child’s health and development is one of their major areas of concern, so it’s important to have a clear and reliable source of truth to look to when you have questions. But ,who should you turn to and what sources should you trust?

Parents might look to apps, social media and other parents to get a sense of their child’s development. Lots of us also rely on the milestones offered by the Centers for Disease Control (CDC) and their program “Learn the Signs. Act Early.” The American Academy of Pediatrics (AAP) developed these milestones, and parents and pediatricians often use them to keep track of a child’s speech and language development.

On the other hand, speech-language pathologists (SLPs) usually rely on milestones established through years of training and experience—as well as guidelines published by the American Speech-Language-Hearing Association (ASHA) and, in Canada, Speech-Language Audiology Canada (SAC). But after the recent changes to the CDC guidelines, there is a deeper disconnect between an SLPs’ typical development timelines and the source parents are most likely to look at. We took a closer look at the updates so you can understand what it all means for your child.

What are the key changes to the CDC milestones?

In early 2022, the CDC and the AAP published revised developmental milestones for the first time in nearly two decades. A group of experts came together (and found consensus) on some updates, including:

  • A reduction in the number of milestones

  • Making the language more parent-friendly

  • Better-defined socio-emotional milestones

  • Additional 15- and 30-month milestones to align with routine check-ups

The changes that caused a stir in the speech-language community are how the CDC reframed what the milestones mean intervention-wise, and how those changes came to be. Previously, the milestones described the skills reached by 50% of children in each age range (50th percentile). If a child was not meeting all milestones, this was considered a warning sign worth discussing with a pediatrician—but not an immediate red flag. But the new guidelines describe the skills reached by 75% of children in each age range. Now, a child missing any one of these milestones is at the 25th percentile, an immediate cause for concern, and parents and clinicians are told that intervention may be necessary.

The shift from previous CDC guidelines, indicating a warning sign when a child fell below the 50th percentile to the current CDC guidelines indicating a cause for concern when a child falls below the 25th percentile.

So, are these changes problematic?

In one way, no. The changes are meant to simplify the decision-making process for parents and to avoid a “wait and see” approach. Now, any delayed milestone is an immediate trigger for action. However, by describing the 75th percentile, these guidelines could postpone parents raising concerns with their baby’s pediatrician even if they suspect a delay. The original CDC/AAP paper lists an example whereby a milestone previously placed at 11 months would be revised to 15 months based on the proportion of children reaching it at each age. But in practice, this might mean that while the previous guidelines gave parents a reason to discuss this missed milestone with their pediatrician at 11 months, they might now only take action at 15 months. This example may be an extreme case, but many smaller delays may add up to similar consequences. This is exactly the concern raised by a number of speech-language pathologists in the field.

 

What was the response from the SLP community?

While the more streamlined approach to delay detection was generally welcomed, the SLP community had a few concerns. They were worried that several revised guidelines did not seem to be backed up by science and that the sources used to justify the milestones did not accurately reflect them.

We had a look at two prominent blogs, The Informed SLP and Speech Sisters, and they suggested that several of the CDC milestones don’t line up with the best practices and standards in the field, including recommendations from ASHA, and normative vocabulary inventories like The MacArthur-Bates Communicative Development Inventories (MCDI). Here’s one example: the new CDC guidelines suggest that a 30-month-old at the 25th percentile should have a vocabulary of approximately 50 words. But this is consistent with the 25th percentile at *19* months on the MCDI. That means the two guidelines are more than 10 months apart, a pretty significant difference, which you can see in the graph.

The other issue raised by SLPs and reflected in a statement from ASHA is that no SLPs were consulted in the milestone revision process. In March 2022, ASHA reached out to the CDC with their concerns and released a follow-up statement with a few clarifications from the CDC: they explained that one of the experts on the panel had prior SLP training and that the guidelines were revised by reviewing the existing literature and databases. The follow-up post also points out that the milestones are not meant to determine who qualifies for speech and language pathology services.

ASHA is still concerned that these milestones will lead to later interventions because they might delay referrals for speech-language therapy. In most cases of language delay, parents are the first to suspect something. But, if parents and clinicians follow the CDC guidelines only, interventions might be delayed for much longer than recommended by SLPs—adding to parents’ anxiety and further impacting their children’s language development.

A complicating factor: Covid-19

The milestone revision process took place in 2019, before the Covid-19 pandemic. Research on infant language development since then suggests that babies born during the pandemic are delayed, falling approximately 15-20 percentage points below the well-established norms. While the reasons for these delays are complex and multifaceted, the fact remains that a much larger percentage of infants are not meeting previously established guidelines. With the scramble to make up for losses from daycare and school closures, it’s still not clear whether the changes to guidelines and pandemic-related delays will mean for children needing intervention.

When should you act?

Back to the question at hand: what do these changes mean for spotting potential language delays in your little one? The advice SLPs have given us is to talk to your doctor and a speech-language pathologist if you’re worried about your child’s speech and language. Your worries and concerns are valid—and the science says that parents are often the first to detect a delay. You do not need a referral to see an SLP in the US and Canada.

And if you’re not ready to speak to your doctor about your child’s speech, that’s also okay. There are lots of different ways to get support, and there are simple things that you can do with your little one during play and throughout your day that can help them make progress and build language skills. Babbly is one way to find information, tips and suggestions that are tailored to your unique child’s skills.

References

  1. Roulstone, S., Law, J., Rush, R., Clegg, J., & Peters, T. (2011). Investigating the role of language in children's early educational outcomes. UK Department of Education Research Report DFE-RR134.

  2. McKean, C., Reilly, S., Bavin, E. L., Bretherton, L., Cini, E., Conway, L., ... & Mensah, F. (2017). Language outcomes at 7 years: Early predictors and co-occurring difficulties. Pediatrics, 139(3).

  3. Fu, E., Chesters, J., & Cuervo, H. (2019). Parenting in the Twenty-First Century: Preparing the Next Generation of Australians or Uncertain Futures. Youth Research Centre, Melbourne Graduate School of Education, University of Melbourne.

  4. Reijneveld, S. A., de Meer, G., Wiefferink, C. H., & Crone, M. R. (2008). Parents' concerns about children are highly prevalent but often not confirmed by child doctors and nurses. BMC Public Health, 8(1), 1-10.

  5. Zubler, J. M., Wiggins, L. D., Macias, M. M., Whitaker, T. M., Shaw, J. S., Squires, J. K., ... & Lipkin, P. H. (2022). Evidence-informed milestones for developmental surveillance tools. Pediatrics, 149(3).

  6. Rannard, A., Lyons, C., & Glenn, S. (2005). Parent concerns and professional responses: the case of specific language impairment. British Journal of General Practice, 55(518), 710-714.

  7. Deoni, S., Beauchemin, J., Volpe, A., & D'Sa, V. (2021). Impact of the COVID-19 pandemic on early child cognitive development: Initial findings in a longitudinal observational study of child health. Medrxiv.

 
Speech DevelopmentMaryam NabaviCDC, early development, milestones