SARS-CoV-2 in infant urine and fecal samples after in utero COVID-19 exposure.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a pandemic that has and will continue to affect many pregnant women. Knowledge regarding the risk of vertical transmission is limited. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) real-time reverse transcriptase-polymerase chain reaction (RT-PCR) of nasopharyngeal swabs typically have been used to confirm the diagnosis among infants, but whether the virus can be detected in other biological specimens, and therefore potentially transmitted in other ways, is unknown. Positive SARS-CoV-2 RT-PCR has been reported from feces and urine from adult patients. We hypothesize that the presence of SARS-CoV-2 in infant urine and fecal samples after prenatal COVID-19 exposure is low. METHODS: We examined the presence of SARS-CoV-2 RNA using RT-PCR in urine and fecal samples among 42 infants born to SARS-CoV-2-infected mothers during different stages of pregnancy. RESULTS: A urine sample was collected from 39 of 42 infants and fecal samples from all 42 infants shortly after birth. Although the majority of the women had the symptomatic disease (85.6%), we were unable to detect the presence of SARS-CoV-2 virus from any infant urine or fecal samples. CONCLUSIONS: SARS-CoV-2 was not detected in infant urine or feces after maternal infection during pregnancy, providing further evidence for low rates of perinatal transmission. IMPACT: SARS-CoV-2 was not detected in the urine or feces of infants of mothers with COVID-19 during various time points in pregnancy. This study provides further evidence for low rates of perinatal transmission of SARS-CoV-2. Results help to provide guidance on perinatal care practices for infants exposed to COVID-19 in utero.

Maternal, Infant, and Breast Milk Antibody Response Following COVID-19 Infection in Early Versus Late Gestation.

BACKGROUND: Coronavirus disease 2019 [severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)] infection at varying time points during the pregnancy can influence antibody levels after delivery. We aimed to examine SARS-CoV-2 IgG, IgM and IgA receptor binding domain of the spike protein and nucleocapsid protein (N-protein) reactive antibody concentrations in maternal blood, infant blood and breastmilk at birth and 6 weeks after SARS-CoV-2 infection in early versus late gestation. METHODS: Mothers with SARS-CoV-2 infection during pregnancy were enrolled between July 2020 and May 2021. Maternal blood, infant blood and breast milk samples were collected at delivery and 6 weeks postpartum. Samples were analyzed for SARS-CoV-2 spike and N-protein reactive IgG, IgM and IgA antibodies. Antibody concentrations were compared at the 2 time points and based on trimester of infection ("early" 1st/2nd vs. "late" 3rd). RESULTS: Dyads from 20 early and 11 late trimester infections were analyzed. For the entire cohort, there were no significant differences in antibody levels at delivery versus 6 weeks with the exception of breast milk levels which declined over time. Early gestation infections were associated with higher levels of breastmilk IgA to spike protein ( P = 0.04). Infant IgG levels to spike protein were higher at 6 weeks after late infections ( P = 0.04). There were strong correlations between maternal and infant IgG levels at delivery ( P < 0.01), and between breastmilk and infant IgG levels. CONCLUSIONS: SARS-CoV-2 infection in early versus late gestation leads to a persistent antibody response in maternal blood, infant blood and breast milk over the first 6 weeks after delivery.