You cannot be made redundant while you are on protected leave.
Once you return from protected leave, you can be made redundant, although of course you are also entitled to a notice period, or payment in lieu.
If you believe that you have been selected for redundancy on the grounds of your pregnancy or related matter, you may have a claim for unfair dismissal. If this is the case you should speak to your Trade Union, Equality Authority, FLAC or a solicitor.