Lucy Grace Cassells was born to Amy Hicks and Nick Cassells, of Crace, in the Woden hospital on Tuesday night, completely oblivious to the milestone and her importance to the hospital.

Clinical midwife manager Christine Fowler said the CatCH program – which stands for "continuity care at the Centenary Hospital" – was established in September 2011 as an alternate model for care for mothers who needed additional attention and care.

"It's an all risk model which means we offer continuity of care to all women and those who have risks like diabetes, past risks such as diabetes, or other concerns and complications," she said.

Ms Fowler said the program assigned one primary midwife to each expectant mother who would care for them until 14 days after the birth of their child.

"The midwives look after three to four mothers each month and are on call 24-hours a day to assist mothers during their pregnancy," she said.

"Anyone can put their name down for the program but it is limited by the number of midwifes who are available to care for the mother and child each month."

Lucy was delivered by midwife Felicity Finn, who has been working as a continuity nurse since the beginning of the program in 2011.

"It's lovely that she was able to look after the 1000th baby because she has been with us since the start and has been talking with the family about the relationship they have built and how important that support is," she said.

Ms Fowler said there were always expectant mothers on the waiting list and word of mouth was one of the most powerful advertising tools for the program, with women coming back to have their second and third babies with the midwifes.

"We get a lot of positive feedback about the program because the mothers build up a relationship with their primary midwife and that's an important thing during a pregnancy," she said.

The program was made possible by a $3 million ACT Government investment in maternity in 2011, which included an expanded range of options to women giving birth in the territory.