About 6% of U.S. completed pregnancies with laboratory evidence of possible recent Zika infection had a fetus or infant with evidence of a Zika-related birth defect, according to a study published online yesterday by the Journal of the American Medical Association. Of 442 completed pregnancies included in the study, 26 fetuses or infants had birth defects, including 18 (4%) with microcephaly. According to a separate study reported yesterday by the Centers for Disease Control and Prevention, Zika virus can continue to replicate in infants’ brains even after birth. For more information on Zika, visit http://www.cdc.gov/zika and http://www.aha.org/zika. A new toolkit from the American College of Obstetricians and Gynecologists also offers Zika resources for clinicians.