If you are off work due to sickness during pregnancy, you should be paid sick pay in the same way as other staff. However, if you are sick during the last four weeks of your pregnancy, your employer can insist that your maternity leave starts, although some employers are happy to overlook odd days of absence.
Once your maternity leave has started, you cannot claim sick pay from your employer if you become ill. Instead, you will receive maternity pay (statutory or contractual) until this runs out.
If you are dismissed or suffer other unfavourable treatment because of a pregnancy-related illness, you are likely to have a claim for pregnancy and/or maternity discrimination. You may also have a claim for sex discrimination and/or automatically unfair dismissal.
It is against the law to penalise you for pregnancy-related sickness absence, even if the decision to treat you negatively (for example, selecting you for redundancy) takes place after you have returned from your maternity leave.
You have a right to written reasons for your dismissal, whether or not you ask for it.
If you have any difficulties with enforcing your rights under these rules, get advice immediately from your union or from a specialist advisor.