There have been over 23,500 calls to the HSE's crisis pregnancy helpline since it was introduced when abortion was legalised.
According to figures released under Freedom of Information legislation, 209 were from girls under 17.
On January 1st, 2019, abortions became legal in Ireland up to 12 weeks pregnancy and in other exceptional circumstances.
Since then, the HSE has had a helpline for unplanned pregnancies, called My Options, which provides information on abortion services and pregnancy supports.
In 2019, 13,214 calls were made and there were 10,381 last year.
575 women made contact after they were 12 weeks pregnant.
Across the two years, there were 209 calls from girls under 17, and 212 from women over 44.
Sinn Féin TD Louise O'Reilly says last year's decrease in calls is a concern.
She said: "I would hope the HSE is going to investigate it, because it is a big drop in numbers.
"It would be interesting to hear whether or not this is become women are getting information elsewhere, or indeed if there's a drop off in demand in the service."
The HSE said the drop in numbers last year wasn't due to any interruption in service during the pandemic, as services continued as normal.
It said there were a higher number of calls in 2019 as the service was new and people were inquiring how it would operate.