Kristen V. Brown writes in The Atlantic:

Starting after Trump’s election, through the end of 2018, 38,000 fewer babies than would otherwise be expected were conceived in Democratic counties. By contrast, 7,000 more than expected were conceived in Republican counties in that same period. (The study, published in 2022, was conducted before data on the rest of Trump’s term were available.) Over the past three decades, Republicans have generally given birth to more kids than Democrats have. But during those first years of the first Trump administration, the partisan birth gap widened by 17 percent.

(Unfortunately, the author later falls for ProPublica’s shoddy reporting on the effects of abortion restrictions on maternal mortality.)