As of January 1, Texas law requires that pregnant women get screened for sexually transmitted infections (STIs) during their first prenatal doctor's visit and again during their third trimester. Previously, mothers received their second screening at childbirth.

“By [moving up] the time at which pregnant women receive their second HIV test, an infected woman can get started on anti-HIV medications sooner and thus significantly cut the risk that she will transmit HIV to her newborn during birth,” said Allison Lowery, a spokesperson for the Texas health department.

Indeed, according to the Centers for Disease Control and Prevention, administering antiretroviral therapy during pregnancy, labor and delivery—coupled with an elective cesarean section for expectant moms with high viral loads—can reduce the rate of mother-to-child transmission to 2 percent or less.