A sampling device adapted for transcervical sampling of biological materials from a pregnant patient comprising: an elongate insertion tube (4) having a first end (5) adapted for insertion through the external orifice (external os) of said patient's cervix and a second end (6) including a handle means (7) for manipulating said tube; a measuring means for determining the position of said first end of said tube within said cervix, wherein said first end (5) includes a sampling head (9, 14) adapted to collect biological material including cells, mucus and biological fluids, and wherein said measuring means is adapted to determine the extent of insertion and transcervical position of said first end to optimise the transcervical sampling site.