More women are having abortions in St Helens, with those aged 30 or over fuelling the trend.
Health experts have warned older women might find themselves excluded from schemes providing free contraception.
And they also say the two-child benefit cap has deterred many women from having a third, unplanned child.
New Department of Health and Social Care data shows there were 630 abortions in St Helens in 2018 – 8% more than in 2013.
That's a rate of 19 abortions per every 1,000 women aged 15 to 44, compared to 17.5 across England.
Of those, 32% were for women aged 30 or over, up from five years earlier when the proportion was 25%.
Clare Murphy, director of external affairs at the British Pregnancy Advisory Service, said the reasons behind the rise are complex.
She said: "Accessible contraceptive services are often focused on the needs of younger women and women over the age of 25 can, in particular, find themselves excluded from schemes providing free pharmacy access to emergency contraception.
"As so many women in the UK rely on pills and condoms as their main methods of contraception, it is vital that there is swift access to emergency options when those methods fail or a pill is missed."
Data shows 99% of abortions under 10 weeks in St Helens were funded by the NHS, in line with the rate five years earlier.
And nine out of 10 abortions were carried out under 13 weeks' gestation, with 76% under 10 weeks.
Across England and Wales, the number of women having an abortion has hit a record high. There were more than 205,000 in 2018 – 7.6% up on five years earlier.
Ms Murphy said greater access to services was also needed for women who are already mothers, and pointed out that unplanned pregnancy in the year after birth is not uncommon, particularly among women who are breastfeeding.
She added: "However, it is also possible that, over the longer-term, couples are making different decisions about family size and the number of children they can afford and feel able to properly care for.
"The two-child benefit cap was designed to influence reproductive decision-making and we are certainly aware of cases where that has been a factor in a woman's decision to end a third, unplanned pregnancy."
Clare McCarthy, spokeswoman for the Right to Life charity, said that proposals to improve access to abortion could see the numbers rise.