Mickey I don't think it has been decided yet what legislation would be brought in if Repeal wins. If the eighth goes, then the government can legislate for abortion, it doesn't have to however, because the current law is a 14 year prison sentence for abortion. So even if the eighth is repealed nothing need change immediately. It is just a step towards legalising and legislating for abortion.
You asked for facts. I am a GP. Currently we have imperfect data on how many Irish women have an abortion. The numbers we do have are those who give an Irish address in the UK (doesn't include those who give a different address or those who go to another country) and those who give an Irish address when ordering abortion pills online (again an underestimate as people can give other addresses, order them abroad or get them from other places). If you add these up you get an underestimate of the number of Irish women having an abortion. These numbers are similar to other European countries.
Here is the WHO data: WHO
Making abortion legal has proved over and over again to not increase the rate of abortion. Things that definitely decrease the rate of abortion are: education about, access to and use of contraception AND societal structures in place that make it easier to raise a child (good quality affordable childcare, supportive employment, supportive family and friends etc).
Because of the need to make arrangements to travel Irish women have abortions later on average than those in countries where abortion is available. This makes it both a slightly more complicated procedure (more likely to be surgical) and more ethically difficult.
Currently the eight amendment has effects on all maternity care. Tests that are standard in other countries are not done much (testing for trisomies etc). It effects women's right to informed consent during pregnancy because what is an obvious fact in other countries (mother's life comes first) is not in Ireland (both lives are of equal value). That means doctors have to wait longer to act just on the off chance that the foetus might still live. This is not medical best practice because it a game of chicken between the doctors and infection taking hold. In other countries doctors can treat straight away and prevent any further complications. While in Ireland you have to wait as long as possible just in case you are convicted of murder (the trouble is waiting as long as possible is not clear cut and medically dangerous).
At the other end. if a doctor decides a ceasarean is in the best interest of the foetus, the woman can be forced to have one: www.theguardian.com/world/2014/aug/17/ireland-woman-forced-birth-denied-abortion (there are other such stories, plenty of women who had a wanted pregnancy).
Here is a good link with a lot of information: parentsforchoice.ie/the-8th-amendment-and-maternity-care/.
In short:
If the eighth is repealed and abortion is legislated for until 12 weeks then the likelihood is that the abortion rate will seem to go up slightly because we will have accurate numbers. Irish women will have abortions earlier than they can now and they will be safer on the whole.
Maternity care will be able to follow medical best practice.