Pregnancy and Antibodies

Maternal Antibody Detection:

Maternal antibodies are a critical component of neonatal immunity. The maternal antibody response to COVID-19 infection to immunization against COVID-19 during pregnancy are important concepts to understand how mothers and babies may be protected from the disease. In one study of pregnant women infected with COVID-19, maternal IgG antibodies were detected in cord blood and thus had been transferred across the placenta after both asymptomatic and symptomatic infection during pregnancy. Recently, the first known case of an infant with SARS-CoV-2 IgG antibodies detected in cord blood after maternal vaccination was reported. At the time of delivery, cord blood antibodies were detected to the S-protein of SARS-CoV-2.

A study of lactating mothers recently diagnosed with COVID-19 did not find SARS-CoV-2 RNA in any sample of their breast milk, though one breast swab detected SARS-CoV-2 RNA. All milk samples contained both IgA and IgG antibodies to SARS-CoV-2 . Lactating women who received two doses of the BNT162b2 mRNA vaccine had antibodies in breastmilk and in serum that included both IgG and IgA. A separate study indicated that lactating women who received either two doses of the Pfizer-BioNTech or Moderna vaccine had elevated levels of SARS-CoV-2 specific IgG and IgA antibodies in breastmilk.

The Centers for Disease Control and Prevention, the American College of Obstetricians and Gynecologists, and the Society for Maternal-Fetal Medicine all recommend that the COVID-19 vaccine should be offered to pregnant individuals who are eligible for vaccination.