A judicial review gets underway today into a decision to downgrade A&E services at the Prince Phillip Hospital in Llanelli.
It comes after campaigners called on the High Court in Cardiff to look into how the decision was made.
The decision to close the neonatal unit at Withybush Hospital in Pembrokeshire will also be reviewed.
Hywel Dda Health Board's decision to restructure specialist neonatal care earlier this year, led to protests.
Local people say they're concerned that premature babies would have to leave the county and travel to Glangwili Hospital in Carmarthen.