The Irish Family Planning Association says some women continue with a pregnancy against their wishes, because of the challenges in trying to travel out of the State for an abortion.
In its annual report released this morning, the IFPA says while some women to access services abroad, other are forced to become a parent.
The report says 26 migrant women with travel restrictions attended the IFPA in the 12 months to the end of September, indicating they wanted an abortion.
Of these, five were forced to continue with the pregnancy while four were considering - or had taken - an abortion pill.
A further 17 did not return to the association and their outcomes are not known.
According to IFPA chief executive Niall Behan: "For decades the Government has relied on women being able to leave the State to access abortion services.
"However, the reality is that many women cannot do so due to legal, financial and other barriers.
"These women face enormous challenges in obtaining the documentation and funds required to travel.
"Under Irish law, the entire burden of accessing an abortion abroad falls on women. Last year, some of our clients with travel restrictions managed to overcome the barriers and travel. Some of our clients tried to obtain the abortion pill.
"However, others had no option but to continue with the pregnancy and parent against their wishes."
The annual report also notes an increase in women over 50 attending for sexual health services, including infection screening, while the number of those aged over 44 more than doubled compared to 2012.
Independent TD Clare Daly is to table a Bill tomorrow night which would remove the current clause equating the lives of a mother and her unborn child.
She says the vote is urgently needed after the case of Miss Y, which showed women are still forced to bear children against their will.
She said the controversial laws issued last year have made the situation worse.