For the remainder of our analysis, pregnant women with evidence acute Zika virus infection, women with evidence of Zika virus (timing of infection undetermined), and women with presumptive Zika virus (IgM positive, PRNT results not available) were analyzed together as having any laboratory evidence of Zika virus infection during pregnancy because their clinical management during pregnancy and the subsequent testing of the infants was the same. This evidence concerns the gene CD40LG and infection.