This has been an ominous year for reproductive rights in America, with states including Georgia, Alabama and now Tennessee in a race to the bottom to pass the most extreme anti-abortion law in the nation.

But while those high-profile abortion bans make their way through the courts — they were designed to provoke legal challenges that could threaten Roe v. Wade — a more immediate threat to women’s health care has been brewing. The Trump administration has quietly been working to gut the Title X family planning program, which helps poor women afford birth control, cancer screenings and testing for H.I.V. and other sexually transmitted infections. On Monday, the administration’s efforts paid off: Planned Parenthood, which serves about 40 percent of Title X patients around the country, felt forced to withdraw from the program.

The nearly 50-year-old Title X program is an unsung hero of American public health. In 2017, Title X clinics served more than four million women, 42 percent of them uninsured, according to the federal Office of Population Affairs, which administers the program. The Guttmacher Institute, a research group that supports reproductive rights, found that Title X clinics helped prevent more than 822,000 unintended pregnancies in 2015. The institute estimates that for every dollar the federal government spends on family planning, it saves more than $7.

The Trump administration’s new Title X rule, announced in February, will lay waste to that progress. The rule bars facilities that receive Title X money from providing abortions, even with a separate source of money, as has been required by law for decades. It also prohibits clinics from referring patients for an abortion at a different facility — in other words, staff members would effectively have to pretend that abortion is not a legal medical option.