The number of babies assessed by a public health nurse dropped by almost 50% during the pandemic.
HSE figures show 53,524 babies were seen during 2019, however the figure dropped to 28,184 in 2020.
Key developmental checks are carried out by a public health nurse during the early years, and most children would undergo five assessments by the time they reach the age of four.
According to the HSE, three of those take place within the first 12 months.
The HSE says during the pandemic, many public health nursing staff were redeployed to support Covid19 related clinical activities.
It says staff have been returning to their core duties recently, which will enable the resumption of a full service.
Kildare GP and Assistant Professor in Public Health and Primary Care at Trinity College - Brendan O'Shea - says delayed developmental checks can have bad outcomes for the children and the health service.
"We pick up thinks like lazy eyes, or click hips.
"if you pick up a lazy eye at a 6 month check it's very easy to manage it. It involves padding the active eye, so that the lazy eye kicks in. So that's a trivial thing, it's low cost and it's very effective.
"If you're picking it up 3 or 5 years later, the outcome is a lot less good and it involves eye surgery."
