What is a GPST1

[Satstar]

Just curious
Am reading through my notes from my labour and after an emcs my baby was immediately taken into another room as resuscitated by a 'GPST1'. Just curious as to who/what this is.

A doctor who is in their first year of training to be a gp

As above but they will have already completed two years as a foundation doctor after qualifying from medical school

A junior doctor who will eventually be a GP who is in their first year of gp training and has been a doctor for at least two years but maybe longer if they switched specialities rather than going straight from foundation year 2 into gp training