A study published in the journal Indian Pediatrics has claimed that Covid-19 can be transmitted from an infected mother to a baby during the perinatal period. The study also suggests increased morbidity in infected infants, with a significant correlation with premature births, indicating at the possibility of increased risk of premature labour in Covid-positive pregnant women.
The study also found that SARS-CoV-2 positive newborns are more likely to be symptomatic, more likely to have respiratory symptoms, and other neonatal morbidities but no significant increase in mortality was seen. Perinatal transmission is defined newborn testing positive in the RT-PCR test for Covid-19 in the first 72 hours after birth and can include transmission that may have occurred in the uterus or during birth.
The prospective cohort study, collected data of newborns from 20 hospitals across India voluntarily enrolled in the National Neonatology Forum (NNF) of India Covid-19 registry, which was initiated in April 2020, and was published in Indian Pediatrics in March this year. Among the 20 hospitals were Arpan Newborn Care Centre in Ahmedabad and Shree Navajivan Children Hospital in Rajkot. The study group included extramural neonates – a baby not born within premises of the treating centre – as well as intramural neonates – a baby born within premises of the treating centre.
The web-based Covid-19 registry received a total of 1,733 entries for mothers and infants, of which 1,711 mother-infant duos were enrolled for the study.Of this, over 90 per cent (1,589) were intramural, while 122 were extramural births. Among the intramural infants enrolled, data of 1,330 neonates were analysed of which 143 (10.8%) were Covid-19 positive. Among these neonates, 106 (8%) tested positive within 72 hours of birth, confirming perinatal transmission, and 21 (1.5%) beyond 72 hours of birth, indicating horizontal transmission. Among the extramural infants, 39 tested Covid positive.
The multi-centre study, that also saw participation from AIIMS New Delhi and Bhubaneswar, also observed that Covid-19 positive neonates were five times more likely to be symptomatic compared to Covid-19 negative neonates and twice more likely to need resuscitation. Respiratory distress, pneumonia, sepsis, seizures, septic shock, jaundice and other morbidities were significantly higher in Covid-19 positive intramural neonates compared to those who tested negative.
“They (Covid-positive neonate group) were also more likely to have received surfactant, steroids and inotropes. The risk of mortality was however not significantly different between the two groups,” the study notes. Notably, among the intramural covid-positive neonates, 68 of the 143 tested positive on day one of birth. These neonates, as the researchers hypothesise, may have acquired the viral infection either inside the uterus or during birth.
“It is also to be noted that many neonates were tested for the first time on day three as per the local protocols, and the absence of testing on the first day after birth could have led to misclassification of the type of infection,” the authors of the study add. With the study finding that Covid-19 infected neonates were significantly more likely to need resuscitation, be symptomatic, need NICU admission, have abnormal chest X-rays, and need respiratory support, a marginally higher incidence of infection in neonates who were roomed-in with mother was also seen although no association with breastfeeding was reported.
The World Health Organization (WHO), however, recommends that neonates should be roomed-in with mother and exclusively breastfed while following precautions to limit the spread infection to neonates. The study notes that a higher incidence of neonatal infection in infants roomed-in with mothers is likely “due to incomplete adherence to the suggested precautions.”
A key limitation, as highlighted in the paper, is, non-uniformity in age at testing of neonates born to Covid-19 positive mothers as well as inability to test for other bodily fluids and parameters to arrive at a conclusion with regard to source and time of transmission.
“As this was a registry-based study, testing of other biological sources like amniotic fluid, placenta, blood, or breastmilk was not pursued. We also did not test for the presence of specific antibodies in the neonatal blood to look for intrauterine infection as suggested by a recent guideline to classify the type of neonatal infection (whether infection was acquired during birth or acquired after birth). We did not capture data for neonates with the possibility of multi-system inflammatory syndrome in children (MIS-C) following SARS-CoV-2 infection, which is recently being reported,” the paper adds