“It’s all about market share,” said Lois Uttley, a senior adviser to the hospital equity and accountability project at Community Catalyst. Uttley, who has been tracking hospital mergers and acquisitions since the 1990s, said that with fewer choices, patients today face more difficulty obtaining reproductive services.

In Schenectady, N.Y., Ellis Medicine is in talks with the multistate Catholic giant Trinity Health. Last month, in Quad Cities, Iowa, Genesis Health System signed a letter of intent to enter a partnership with MercyOne, also part of Trinity Health. And this semester, Oberlin College had to find a new provider to prescribe contraceptives after outsourcing student health services to a Catholic system that would not provide them.

In rural northeast Connecticut, residents are protesting the prospect of their 128-year-old hospital becoming part of a Catholic system and the potential impact on reproductive services.

“It would be very troubling to see . . .