The introduction of relaxed abortion legislation in Northern Ireland could cost just over £5m a year - putting "strain" on an "already over-stretched health service", a senior economist has warned.
Dr Esmond Birnie said amid the "big moral issues", it would be "naive to forget a public expenditure cost" from the changes Parliament has proposed.
The House of Lords agreed last week to revised proposals that mean the law could change here by early 2020, following the historic Commons vote when MPs backed a controversial amendment to extend access to abortion here.
This would effectively bring NI into line with the rest of the UK.
MPs also voted overwhelmingly to extend marriage rights to same-sex couples, with both votes requiring Westminster to act if a new Stormont Executive is not formed by October 21.
Economist and commentator Dr Birnie said the financial implications of any changes to abortion law had not yet been raised by politicians.
"If NI adopts abortion laws as liberal, possibly even more liberal, as those which have applied in Great Britain since 1967, there will inevitably be an additional demand on the public healthcare system. That addition could be at least £5m annually," he said.
"This will strain the already over-stretched health service. Five million might look like a small part of a departmental spend of £5,000m-plus annually. But this is money which will not be available to spend on mental health services or reducing waiting lists."
Pointing to NHS England, which Dr Birnie projected will spend £150m on abortion services in 2020, he estimated that if the same percentage of funding was applied to Northern Ireland's population, it would amount to £5.1m.
He warned there would be a knock-on effect on other services. "Some may argue that £5m would be a drop in the ocean," continued Dr Birnie. "The NHS in Northern Ireland already spends more than £5bn every year. Five million would be equivalent to one tenth of one per cent of the existing total spend.
"Hence the necessary funds could surely be found, so it might be claimed, if necessary by a little bit of internal adjustment within the NI health service or more efficiency or by using some of the money which is found each year by re-allocating departmental under-spends."
He added: "Perhaps Westminster might wish to be generous and would adjust the NI block of funding for public spending. After all, it is English, Scottish and Welsh MPs who forced through this change?
"However, whatever way the budget is squared it is inescapable that money spent on providing many more abortions in NI will not be available to spend on other types of healthcare or other desirable outcomes."