In the ANA-weakly positive group, HCQ significantly reduced the incidence of preeclampsia (6.76% vs. 28.30%, p = 0.002), early-onset preeclampsia (1.35% vs. 13.21%, p = 0.027), and small-for-gestational-age infants (7.89% vs. 35.19%, p < 0.001). Here, BTG3 is linked to preeclampsia.