In fact, some researchers think baby fever is a reaction to infertility struggles, not a ubiquitous maternal urge. Many women never experience baby fever, because they successfully get pregnant within a few months of going off contraception. But if months go by without a pregnancy, “these kinds of yearnings are triggered because it’s something that you really want, and you have a blocked parenthood goal,” Boivin says. The “broodiness”—as baby fever is called in the U.K.— “is not the cause of you wanting to have children. It’s a consequence of you wanting to have children and not being able to have them.”

Rackin suggested that binary notions of motherhood—either you want it or don’t; you either have baby fever or not—originated back when most women were expected to have kids. But now society has ratcheted up what it takes to be considered a “qualified” parent. The norms of upper-middle-class life pressure people to have an education, a job, a car, a house, and a stable spouse before they even consider parenthood. “It’s really hard to check all those boxes off and be able to say, ‘Now I’m going to try to have a baby,’” Rackin said. It’s less romantic and more daunting to turn 36, pass the bar exam, and get your IUD removed than it was to get pregnant on your honeymoon as a 21-year-old in 1957. Avoiding planning too hard or too purposefully is a way, for some people, to “not have to feel bad about not checking all those boxes before having a child,” Rackin said.

In that way, baby fever can feel like another societal box to check, another thing about which to think, I don’t have it, so I must not be ready.