Mechanism of Materno-Fetal Transmission
Possible discussion on the vertical transmission have been discussed by many authors with most of them believing there’s insufficient data on vertical transmission from the mother to her fetus24-27. Scientists have run SARS-CoV-2 RT-PCR analysis on COVID-19 positive mothers’ breastmilk samples and specimens of amniotic fluid, blood from the umbilical cord and throat swabs from the neonates. All of these tests have found a negative presence of the viral antigen in the abovementioned specimens, thereby making the physicians unsure of materno-fetal transmission16.
A possible vertical transmission was reported in a 34 weeks gestational mother who presented with respiratory difficulties, had patchy-ground-glass opacities on Chest CT and had a positive RT-PCR on nasopharyngeal swabs. Her infant girl was delivered by caesarian section in a negative pressure isolation room and had no symptoms, but was immediately quarantined in the neonatal intensive care unit. After 2 hours of birth, her the SARS-CoV-2 IgG level were reported to be 140.32 IU/mL and the IgM level were recorded at 45.83 IU/mL. Immunological cytokines such as IL-6 and IL-10 were raised at 28.26 pg/mL and 153.60 pg/mL respectively with an elevated white blood cell count of 18.08 × 10^9/L. Her SARS-CoV-2 IgM and IgG level remained above normal limits at the time of discharge 15 days after birth. This too was consistent with abovementioned findings of negative SARS-CoV-2 breastmilk RT-PCR28.
Among other plausible ways of SARS-CoV-2 infection, in addition to vertical transmission are: close contact transmission, droplet transmission from family members & family visitors and nosocomial infections. If the mother does get tested positive, the newborn should be isolated and observed as soon as possible, and nucleic acid tests should be carried out, too. In addition, breastfeeding should not be performed if the mother was infected by SARS-CoV-229, even though WHO strictly doesn’t prohibit breastfeeding, it does recommend caution.