No vertical—mom-to-baby—transmission of SARS-CoV-2, the virus that causes COVID-19, occurred in a study of 64 pregnant women with confirmed COVID, reports a study yesterday in JAMA Network Open.While placental positioning of the angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) receptors—two main ways SARS-CoV-2 enters cells—may provide fetal protection in utero, the researchers found unexpectedly low transference of SARS-CoV-2 antibodies from mother to child.The study, led by Andrea Edlow, MD, maternal-fetal medicine specialist at Massachusetts General Hospital, and funded by the National Institutes of Health (NIH), focused on mothers in the third trimester of pregnancy, which is when the highest transfer