Mothers-to-be may have to make the two-hour journey down the A9 to Raigmore Hospital in Inverness as NHS Highland revealed that the situation in the obstetric department at Caithness General Hospital in Wick is "very precarious" and the service is "fragile".
The staff shortage has raised fears in the community that the six-bed unit could be under threat of closure again.
The health board has advised it may have to cut the obstetric and gynaecology services to daytime only, and out-of-hours maternity care would be affected, with the possibility of pregnant women transferring to Inverness.
The staffing difficulty came after one of the three consultant obstetricians left in December and a new locum died.
Gill McVicar, NHS Highland director of operations, said: "This, together with leave commitments, leaves a very precarious staffing situation and a fragile service."