Sive,
The previous posters have set a number of potential routes of redress. Persoanlly, I don;t think they are legally valid. These are my reasons why:
Claim under Fixed Term Work Act 2003:
After 4 years continuous service, under the Fixed Term Work Acts 2003, a fixed-term worker can generally assert a right in law to a permanent contract.
However, contrary to the other posts in this thread, there is nothing preventing an employer from ensuring that an employee does not become permanent. This may be acheived by prior planning to ensure that a person's service comes to an end before the 4 year threshold is reached.
Whilst there a provision in the 2003 Act effectively outlawing any agreement put forward by an employer that seeks to sidestep their obligations under the 2003 Act, this provision relates to clauses inserted into a contract stating "The 2003 Act shall not apply" etc. This does not arise where the term of a contract merely expires prior to an employee attaining 4 years continuous service.
There is little difference between this concept and residential lease agreements that are designed to expire just prior to 4 years of continuous occupation by a tenant, so that a landlord can insure that a tenant cannot then claim any of the rights and benefits arising under Part 4 of the Residential Tenancies Act.
Claim under Unfair Dismissals Acts
Whilst it is unlikely that you can assert any right under the 2003 Act, you may be able to claim unfair dismissal under the Unfair Dismissals Acts on the basis of the fact that you have more than one year's continuous service.
However, you will need to check your employment contract to see if there is a specific clause relating to the unfair dismissals acts and, in particular, a clause that states the Unfair Dismissals Acts will not apply for a termination of employment arising solely by reason of the expiration of the contract.
Under the Unfair Dismissals Act 1993, the insertion of such a clause is a cast iron defence for an employer against any claim of unfair dismissal by a fixed term worker - where such claim relates to their dismissal arising from their contract running out of time. However, such a clause must be explictly set out in a contract for an employer to rely on this "carve-out".
Claim under Equality grounds / Maternity Protection Acts:
The issue of your pregnancy is nothing more than an unfortunate coincidence. There is no suggestion that pregnancy was on the cards when you entered into your current contract. As such , there is clearly no link between the expiry of your contract and the fact that you are now pregnant. This rules out a claim under the Maternity Protection Acts.
Nothing you have said suggests that any other fixed-term worker is being kept on and made permanent.The only basis for an equality claim on the grounds of family status/gender would be if you were treated differently than another comparable employee who was not pregnant (or who was male).
Conclusion:
In light of the above, I would suggest that the only possibility for a claim would arise if your contract does not include an Unfair Dismissals Acts "carve-out".