The debate surrounding filiation in the contemporary context is cer- tainly stress-testing the methods and rules of Private International Law, in their interrelation with Human Rights Law and, inevitably, with the differ- ent ways in which society reacts to new procreative techniques such as maternal surrogacy and assisted procreation. In the European Union, there are many different approaches on the matter on behalf of domestic rules, both from the perspective of substantial Family Law and of Private Inter- national Law. From the perspective of EU Law, this situation may create obstacles to the exercise of free movement rights of children and their fam- ilies and infringe/undermine Human Rights. From this, the decision of the European Commission to present the Proposal for a Regulation COM(2022)695. However, until the new instrument is adopted, the effec- tive and coherent application of the EU acquis is at times dependent on the operation of domestic law. The UniPAR project, co-funded by the European Commission, aimed at improving the effective and coherent application of the EU acquis by i) identifying parenthood issues arising in connection to existing EU second- ary law, also considering the possible impact of the future Parenthood Reg- ulation at the EU level; ii) analyzing how parenthood is dealt with in the (PIL) domestic law in six jurisdictions, also on the basis of sample cases; iii) discussing the issues with stakeholders, and by developing final Con- clusions and Reccomendations. The present contribution contains the re- sults of the aforementioned research activities.