A family planning provider has suspended surgical abortions for girls under 18 and vulnerable women after safety concerns were raised by the Care Quality Commission (CQC).
A number of other services offered by Marie Stopes International (MSI) have also been halted to make sure patients are protected from potential harm when undergoing pregnancy terminations.
These include the suspension of terminations under general anaesthetic or conscious sedation, and the suspension of all surgical terminations at the provider's Norwich centre.
The intervention by the CQC means 250 women will be sent to other providers.
Marie Stopes International is required to keep the restrictions in place until it has assured the regulator it has appropriate systems in place to care for all of its patients safely.
Professor Edward Baker, deputy chief inspector of hospitals at the CQC, said: "Given the nature of the concerns we identified on our inspections, it is right that Marie Stopes International has suspended a number of its services.
"We will report fully and publicly on our inspection findings as soon as our regulatory process has concluded and we are able to do so."
After planned inspections, the CQC identified a number of concerns linked to the provider's governance arrangements and subsequently carried out an unannounced inspection of MSI's corporate headquarters in England last month and of its call centre on August 12.
The concerns raised related to poor governance arrangements, giving rise to specific immediate concerns relating to the lack of assurance in MSI, in areas such as consent and safeguarding, and the lack of assurance in relation to training and competence in conscious sedation and general anaesthesia.
Professor Sir Bruce Keogh, NHS England's national medical director, said: "This will be an anxious time for those women affected and we are taking immediate action to ensure everybody involved has access to the appropriate confidential advice and services."
The restrictions will take effect immediately and NHS England has set up a confidential helpline on 0300 123 1041 from 9am to 5pm at weekends and 9am to 8pm during the week.
Patients who have already been booked in for procedures that have now been restricted are being contacted so they receive their care at an alternative provider.