The number of babies assessed by a public health nurses dropped by almost 50 per cent during the pandemic.
HSE figures show 53,524 babies were seen during 2019, however the figure fell to 28,184 in 2020.
Key developmental checks are carried out by a public health nurse during the early years, and most children 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 Covid-19 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 things like lazy eyes for example, we pick up clicky hips. If you pick up a lazy eye at a six month check it's very easy to manage it. If you're picking it up three or five years later the outcome is a lot less good and it involves eye surgery."
