You can decriminalise self-abortion whilst not changing the regulations that doctors work under. Women wouldn't be able to turn up at 32 weeks LMP demanding an abortion because the doctor would refuse on the grounds that he's not allowed to do that. Were she to take matters into her own hands, she would not be arrested.
This would be inline with the views stated by several posters that the woman needs mental health support, not jail. It allows for the "we shouldn't enable that" and "she shouldn't be jailed for it" views to co-exist.
Northern Ireland has decriminalised self-abortion and has fully on-demand doctor-assisted abortion but the time limit is only twelve weeks. It's crazy that NI, home of the DUP, has more liberal abortion laws than the rest of the UK. The rest of the UK's sentencing, up to life, is the most severe in Europe.