More than 1,000 women from Northern Ireland travelled to England or Wales for abortions last year.
The NHS does not charge patients from the region for the procedure because it is largely unavailable at home.
Northern Ireland has the strictest law surrounding terminations in the UK or Ireland.
Imogen Stephens, Marie Stopes UK’s medical director, said: “It is shameful that, in 2018, more than 1,000 women from Northern Ireland are still being forced to travel to England to access abortion care, including those who have become pregnant as a result of rape or incest or whose foetus has no chance of survival outside of the womb.
“Many more women are unable to travel and have no option but to risk prosecution by ordering pills online or continuing a pregnancy they do not want.”
Marie Stopes provides lawful abortion services in the UK.
Ms Stephens added: “Marie Stopes UK calls on the UK Government to stop this suffering and ensure Northern Irish women are finally afforded the caring and compassionate services they deserve.”
In 2018, there were 1,053 abortions for women from Northern Ireland, an increase of 192 from 2017, the Department of Health and Social Care said.
The Democratic Unionists are adamantly opposed to any liberalisation of Northern Ireland’s abortion law.
Unlike other parts of the UK, the 1967 Abortion Act does not extend to there.
A termination is only permitted if a woman’s life is at risk or if there is a danger of permanent and serious damage to her mental or physical health.
Campaigners want the UK Government to legislate in the absence of Stormont powersharing.
Grainne Teggart, Amnesty International’s Northern Ireland campaign manager, said it is unsurprising that the number travelling has increased.
She added: “The ongoing near-total ban on abortion doesn’t stop women needing or seeking abortions, it just forces them to board planes to access the healthcare.
“Women should be treated with respect and dignity and given the right to make choices about their own body at home.
“It’s clear that change needs to happen.
“It’s degrading and insulting that the UK Government allows women in Northern Ireland to travel to receive vital healthcare services, but will not give us this same access at home.”
Marion Woods, spokeswoman for anti-abortion group Both Lives Matter, said she was disappointed but not surprised by the increase.
“It remains the case that the rate of abortion in Northern Ireland is nowhere near the figure of 17.4 per 1,000 women which the 2018 figures reveal for England and Wales. We know our law and policy saves lives,” she said.
More than 100,000 people are alive today who would otherwise not be if Northern Ireland had adopted the 1967 Abortion Act, she added.
“It’s tragic to see that over 200,000 abortions took place in 2018 in England and Wales and of these 39% were to women who had had at least one abortion previously.
“It was once said by pro-choice campaigners that abortion should be ‘safe, legal and rare’.
“The “rare” seems to have been long forgotten now. Can we really be expected to believe that these statistics represent progress for women?
“This highlights once again the need for the restoration of some form of local political governance so that positive steps can be taken to support both lives in every pregnancy.
“There are some great services in place, but women facing crisis pregnancies still need more support.”