BAR HARBOR – As part of an overall $3.5 million capital campaign, officials at Mount Desert Island Hospital announced plans Tuesday to renovate part of the hospital into a modern obstetrics unit.

About 2,500 square feet of space on the top floor of a hospital wing built in 1937 is being renovated for the facility, which will cater to expectant mothers who choose to give birth at the hospital. The four new rooms will be larger than the four rooms in the existing obstetrics unit and will help provide patients with more privacy, security and modernized care, Art Blank, MDI Hospital president and CEO said Tuesday.

“What we do for them is different today than what we did years ago,” he said.

There will be two postpartum rooms and two birthing rooms, one of which will have a built-in tub for women who opt for underwater births. The hospital now has a portable tub that staff fill, empty and clean by hand.

One of the postpartum rooms, for use by women after they give birth, will have a double bed for families that want to be together after the birth of a child, officials said. Overall, the new facility will have 700 more square feet of space than the existing unit.

The $750,000 renovation represents a needed change at the hospital, according to hospital executives.

“Over time, things have to change,” said Linda Robinson, a certified nurse midwife. “A lot of health care facilities don’t do that and become obsolete.”

Jeanne Fortier, the hospital’s vice president of clinical services, said the new unit would have improved security to help prevent the kind of newborn abduction that happened at Eastern Maine Medical Center in Bangor in 1996. Access to the new obstetrics unit will be more restricted, she said, and newborns will wear bracelets that will activate locks at the unit’s entrance if the babies get too close.

“It’s a shame you have to do that,” Blank said.

The hospital, which has enough beds to accommodate up to 25 overnight patients at a time, plans to relocate all of its inpatient units. In addition to the obstetrics unit, the medical-surgical, critical care and telemetry units eventually will be moved from the first floor to the second floor of the facility.

Blank said all of the planned renovations should take about three years to complete.

Hospital staff have donated $181,000 to the $3.5 million campaign, which is more than twice the amount expected, according to Blank. Seasonal Bar Harbor residents Ruth and Tris Colket have donated $1 million toward the campaign, with half of that being used as a challenge grant to the community.

About $700,000 remains to be raised to reach the goal of the campaign, which also will fund the purchase of medical technology and establishment of a nursing education endowment, according to written statements released by the hospital.