Fig 1. Impact of inclusion and exclusion criteria on study population.

^a Abbreviations: BP, blood pressure; KPNC, Kaiser Permanente Northern California; KPSC, Kaiser Permanente Southern California; KPWA, Kaiser Permanente Washington. ^aA woman may meet more than one exclusion criterion within a box. Detailed information about inclusion and exclusion criteria is found in S1 Table in S1 File. ^bThe index fill was defined as the earliest fill after the first prenatal visit (typically at 8–10 weeks’ gestation) or, if the visit date was not known, at ≥ 10 weeks gestation.