Families in US took 1,900 care home babies
A total of 1,918 babies were adopted by US families from mother and baby homes here between 1950 and 1973, records have outlined.
A new report into the controversy has also identified that babies who were born illegitimate were almost four times more likely to die than those whose mothers were married.
Children's Minister James Reilly has announced Judge Yvonne Murphy as chair of the Commission of Investigation into treatment of women and their babies at the homes.
The report said it is expected that nine institutions will be included in the investigation.
They are Ard Mhuire in Dunboyne, Meath, Bessboro in Cork, Manor House in Westmeath, Sean Ross Abbey in Tipperary and Bethany Home in Dublin.
Pelletstown/St Patrick's, Tuam home in Galway, Kilrush home in Clare and St Gerard's in Dublin were also included.
But it is not clear if the Magdalene Laundries and Protestant run homes will be included in the investigation.
"It would be too premature for me to say they will at this stage," Dr Reilly said.
"I am not by any means saying that they will not be."
Separately, it was revealed that 6,109 adoptions were recorded between April 1, 1950, and March 31, 1973.
The true figure may be higher as a small number of records are missing for the period between 1968 and 1971. Nearly 500 corpses of infants were transferred to university medical schools for teaching and research from the 1940s to 1960s.
It will be necessary to ensure there is a strong legal basis for an inquiry into vaccine trials on children in some of the homes between the 1960s and 1970s, the report adds.
Although previously reported, the commission has pledged to reveal the full extent of records on this practice.
However, the report said that the commission is not likely to be a suitable or effective vehicle for addressing the "very real interest of individuals" in securing access to their own personal and individual records.
The report was drawn up as a reference and background to the Commission of Investigation.