Analysis of SARS-CoV-2 vertical transmission during pregnancy

Abstract

The impact of SARS-CoV-2 infection during gestation remains unclear. Here, we analyse the viral genome on maternal and newborns nasopharyngeal swabs, vaginal swabs, maternal and umbilical cord plasma, placenta and umbilical cord biopsies, amniotic fluids and milk from 31 mothers with SARS-CoV-2 infection. In addition, we also test specific anti-SARS-CoV-2 antibodies and expression of genes involved in inflammatory responses in placentas, and in maternal and umbilical cord plasma. We detect SARS-CoV-2 genome in one umbilical cord blood and in two at-term placentas, in one vaginal mucosa and in one milk specimen. Furthermore, we report the presence of specific anti-SARS-CoV-2 IgM and IgG antibodies in one umbilical cord blood and in one milk specimen. Finally, in the three documented cases of vertical transmission, SARS-CoV-2 infection was accompanied by a strong inflammatory response. Together, these data support the hypothesis that in utero SARS-CoV-2 vertical transmission, while low, is possible. These results might help defining proper obstetric management of COVID-19 pregnant women, or putative indications for mode and timing of delivery.

Vertical Transmission of SARS-CoV-2 from COVID-19 Infected Pregnant Women: A Review on Intrauterine Transmission

“…As per that classification system a neonatal congenital SARS-CoV-2 infection is confirmed if it fulfills criteria: 1) the virus is detected from amniotic fluid through intact amniotic membrane, 2) the virus is detected in the blood of newborn early after birth. In the current review, one case report [21] and one prospective study [22] confirm the intrauterine transmission by fulfilling the above mentioned case definitions. In addition, magnetic resonance imaging of the newborn [21] showed bilateral gliosis of the deep white periventricular and subcortical matter.…”

“…Of 16 studies included in the current review, four [8][9][10][11] reported no vertical transmission. Twelve studies [12][13][14][15][16][17][18][19][20][21][22][23] reported vertical transmission (probable or confirmed). In 10 studies, SARS-CoV-2 reverse transcriptase polymerase chain reaction (RT-PCR) of newborns was positive and in other two studies SARS-CoV-2 IgM antibodies were detected in the newborns (Table 1).…”

“…In a recent multicenter prospective study [22] conducted in Italy, 31 pregnant women with confirmed COVID-19 infection were enrolled. Biological samples were collected at admission, delivery and postpartum.…”

Severe Acute Respiratory Syndrome Coronavirus 2 Placental Infection and Inflammation Leading to Fetal Distress and Neonatal Multi-Organ Failure in an Asymptomatic Woman

“…Further studies in pregnant women with an active or a COVID-19 infection during pregnancy are warranted to investigate if morphological and histopathological placental characteristics are specific for SARS-CoV-2 infection and if these findings are associated with clinical perinatal outcome. Until now, only a few confirmed cases of vertical transmission of SARS-CoV-2 have been reported [ 4–8 ]. In our case, despite the massive placental infection, all neonatal samples were negative for SARS-CoV-2, and we found no evidence for vertical transmission.…”

“…In general, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy is not considered to be an increased risk for severe maternal outcomes but has been associated with an increased risk for fetal distress [ 1 ]. Localization of SARS-CoV-2 particles in placental tissue has been visualized [ 2 , 3 ], and recently, a few cases of vertical transmission of SARS-CoV-2 have been reported [ 4–8 ]. Besides related to direct in utero infection with SARS-CoV-2, the mechanisms leading to the adverse perinatal outcomes are not well understood.…”