Emergency services are growing “increasingly concerned” for the welfare of a mother whose baby boy was found dead in an area of woodland.
Hampshire Constabulary are trying to trace the woman after her newborn was found close to Short Road in Hythe, near Southampton at about 14:00 GMT.
Health professionals said it was “vitally important” she sought medical assistance.
The baby’s death is being treated as unexplained, police said.
Suzanne Cunningham, director of midwifery at University Hospital Southampton, said: “You may not want to call the police, but please speak to someone be that a healthcare professional, a GP or by attending hospital.
“This will undoubtedly have been a very distressing time for you and it is vitally important you seek medical assistance.”
Ms Cunningham appealed for anyone who had concerns about someone who had recently been heavily pregnant to contact them.
Insp Helen Andrews said the baby was white and born “either full-term or close to full-term”.