The NHS is planning to cut services at the Friarage Hospital in Northallerton, claiming they are unsustainable.
Last month the health secretary rejected calls for an independent review of the plans, saying a public consultation was appropriate.
The consultation is expected to start at the end of July or early August.
The preferred option of NHS Hambleton, Richmondshire and Whitby Clinical Commissioning Group (CCG) is to replace overnight children's care at the Friarage with a day care assessment unit, and to have midwife-led maternity services instead of consultant-led.
It would mean pregnant women at risk of complications travelling to hospital in Middlesbrough, 22 miles (35km) away, to give birth.
Dr Vicky Pleydell, the CCG's chief clinical officer, said: "The case for change is clear, and it would not be safe for the service to remain as it is currently.
"The number of sick children requiring inpatient care and number of high-risk births are too small to support the size and experience required of medical teams to ensure a safe and high-quality service.
"Our preferred option would mean that the vast majority of children's and maternity services at the Friarage would be retained and women would still be able to choose the Friarage for low-risk births.
"We aim to start the consultation as soon as we have a project team in place."
A public consultation into plans to reduce maternity and child services at a North Yorkshire hospital is to be held in the next two months.