The study by Edlow and colleagues1 carefully characterizes several key biologic parameters of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy, including maternal viral load and antibody response, transplacental antibody transfer, and placental pathology in 64 pregnant women with reverse transcription–polymerase chain reaction (RT-PCR)-confirmed SARS-CoV-2 infection. Women were prospectively enrolled at 3 Harvard-affiliated hospitals in Boston, Massachusetts, (ie, Massachusetts General Hospital, Beth Israel Deaconess Medical Center, and Brigham and Women’s Hospital) during the first wave of the pandemic in the Northeast during April 2, 2020 through June 13, 2020. A major strength of this study is that it included 2 comparison groups that were enrolled contemporaneously at the same hospitals as the cases: pregnant women with RT-PCR results negative for SARS-CoV-2 infection, as well as nonpregnant women of reproductive age.1 For characterizing viral load and antibody response in pregnancy, a control group of nonpregnant women of reproductive age with SARS-CoV-2 infection is most appropriate. For characterizing differences in transplacental antibody transfer and placental pathology, a control group of pregnant women without SARS-CoV-2 infection is most appropriate. In addition, as a comparison for evaluation of mother-to-neonate transfer of anti–SARS-CoV-2 antibodies, Edlow et al1 included measurement of mother-to-neonate transfer of anti-influenza antibodies. These careful studies with inclusion of appropriate control analyses bring us closer to understanding not only the characteristics of SARS-CoV-2, but the characteristics of other viruses during pregnancy; these could provide insight to the characteristics of viruses that might emerge in the future.