A 27-year-old woman found dead in a terraced house was pregnant, say police.
West Mercia Police formally identified Kimberley Russell, known as Kim, as the woman found dead at a house in Brookside, Telford, on Monday.
A post-mortem examination to try to establish the cause of death proved inconclusive.
A 33-year-old man was arrested on suspicion of murder yesterday, and is still being questioned by detectives.
Officers were called to the home after concerns for welfare were raised and forced the door to gain entry.
Detective Inspector Steve Tonks, the senior investigating officer, said: "Our investigation is on-going and although we do not yet know the exact cause of Kim's death, we are continuing to treat this as a murder investigation while we await the result of further tests.
"I can confirm, however, that Kim was pregnant when she died and clearly this makes her death even more of a tragedy.
"I'd like to reassure local residents that a significant number of resources continue to be dedicated to this investigation and we will continue to use specialist officers until we resolve this case."
He appealed for the public's help in finding out what happened and urged people to come forward with any information "no matter how small or insignificant" it seemed.
Anyone with information can call police on 0300 333 3000 or call Crimestoppers anonymously on 0800 555 111.