BEVERLY — Hundreds of mothers from across Massachusetts are rallying together to stop the North Shore Birth Center from closing.

They've called friends, organized meetings, started a blog and a Facebook page, and are launching a letter-writing campaign to the board of trustees of Northeast Health Corp. — which owns Beverly Hospital and the birth center.

Ipswich mother Pav Kneedler, who organized the campaign, said she heard on Nov. 18 the board will receive a proposal to no longer allow women to have babies at the center.

A statement from the North Shore Birth Center said no final decision has been made and did not mention a closing date.

"As with other birth centers around the nation, North Shore Birth Center is experiencing a significant rise in the cost of malpractice insurance premiums," the statement said. "As a result, we are currently evaluating the services provided by North Shore Birth Center."

Opened in 1980, it's the first freestanding birth center in the Northeast. The only other center in the state is in Cambridge.

The North Shore Birth Center is tailored to women with low-risk pregnancies who want to give birth naturally, with no drugs, in a quiet, private setting. Its two delivery rooms are an alternative to having a child in a clinical setting. It's similar to a home birth — except it's covered by most insurance and on the Beverly Hospital campus so patients can easily be transferred should problems arise.

"It's the best of both worlds," Kneedler said. "I had both my boys there."

In a quiet, dimly lit room, she relaxed in a Jacuzzi, surrounded by her husband and two midwives, and she gave birth naturally to her son Alec.

"You have this healthy baby, and you did it all by yourself," she said. "It's just an amazing experience. It gives you strength in your life, and I think it also changes who you are."

Kneedler, who has worked on and off as a labor and delivery nurse for 10 years in Salem and at other hospitals, said she understands natural births are not for everyone.

"There are plenty of women who just want to know when they can have their epidural," she said.

But some women would prefer to allow labor to unfold on its own in a calm, peaceful environment, she wrote in a letter to the board of trustees.

"Had the birth center not been doing births, we would have a home birth, and I fear that is what will happen should you stop allowing births at the Birth Center," she wrote. "You will lose those clients — they will not simply say, 'Oh, well, let's just do it at the hospital.'"

Kneedler said her letter is the first of many. More than 100 people are expected to show up tomorrow morning at the Crunchy Granola Baby in Salem to talk about the rumored proposal and to brainstorm what to write to hospital trustees.

"It would be a shame to lose this resource," Kneedler said.