As the birth-sites of planets, protoplanetary discs have become the object of intense study during the last years. Constraining their typical lifetimes, masses and/or sizes is crucial to understand the process of planet formation. These objects are a natural by-product of early stellar evolution, and therefore a high fraction of Pre-Main Sequence Stars (PMS) are surrounded by a protoplanetary disc. The current census of PMS (and discs) has been limited due to instrumental restrictions (i.e. sensitivity), but this situation is going to change thanks to projects like Gaia. In this talk I will present the results of applying density-based clustering algorithms to the Gaia DR2 dataset with the aim of identifying new members of the Ophiuchus star forming region. I will briefly describe our methodology and present the ~200 potential new PMS that we find.