One of the country's lead clinicians for foetal medicine believes the timeframe given for the introduction of abortion services is unrealistic.
Doctor Keelin O'Donoghue - who supported the Repeal campaign - says the January rollout is too soon.
Last week, the Seanad passed the Terminations of Pregnancy Bill - the last major hurdle in making abortion services legal in Ireland.
Dr O'Donoghue says making sure all the necessary precautions are in place takes time and a January start date is not achievable.
"I'm afraid that if this is introduced in January in this way, this service will not be what women deserve," said Dr O'Donoghue.
"This is really personally and professionally challenging for many health care professionals and it has the potential to cause significant workplace conflict around values and choices.
"And I think there has been a failure to recognise the complexities involved in working in maternity hospitals."