The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to the death of millions of individuals throughout the world. SARS-CoV-2 infections have been reported in pregnant and non-pregnant women of all age groups. However, the utero maternal-fetal transmission mechanism of the SARS-CoV-2 is still unknown.

Study: Maternal-Fetal Implications of SARS CoV-2 Infection during Pregnancy, Viral, Serological Analyses of Placenta and Cord Blood. Image Credit: Rinanda Adelia/Shutterstock

Few studies observed that SARS-CoV-2 was not recovered from the placenta or nasopharyngeal swabs of those neonates born to mothers who had tested positive for COVID-19, while some indicated the presence of elevated SARS-CoV-2 IgM antibody in the neonate’s blood. Therefore, the management of newborns born from mothers infected by COVID-19 is still problematic due to the lack of guidelines and evidence.

A new study published in the International Journal of Environmental Research and Public Health evaluated the pregnancy outcomes of pregnant women in the third trimester who were infected by SARS-CoV-2 for the detection of the virus in the placenta and different samples of the newborn as well as detection of antibodies in the cord blood.

About the study

The study recruited pregnant women between 18 and 49 years of age infected with SARS-CoV-2 from 5th May 2020 to 1st May 2021. Anal and gastric swabs were collected from newborns along with placenta samples and cord blood.

Detection of SARS-CoV-2 was carried out with the help of real-time polymerase chain reaction (RT-PCR), while SARS-CoV-2 serology was determined by an immuno-enzymatic technique by chemiluminescence. Furthermore, the demographic characteristics of the recruited patients, their medical history, comorbidities, symptoms, and results of the SARS-CoV-2 PCR and/or SARS-CoV-2 serology were also recorded.

Delivery mode, Apgar scores, birth weight, and umbilical artery pH were also recorded to monitor the fetus. Finally, clinical and biological follow-up and ambulatory patients follow-up was carried out.

Study findings

The results indicated that out of the 45 pregnant women recruited in the study, most were ambulatory, while 10 required hospital admission due to severe symptoms of fetal distress. The clinical symptoms for most of the patients with COVID-19 included fever, diarrhea or vomiting, headache, cough, ageusia, dyspnea, anosmia, and asthenia.

Among the 45 participants, 38 delivered vaginally while 7 had a cesarean delivery (CD), and one was found to be a twin pregnancy. Two women were found to be admitted to the intensive care unit (ICU) with mechanical ventilation for 30 to 45 days post-cesarean delivery due to severe COVID-19 infection. These two women were older than others and also possessed comorbidities.

Among the 46 newborns, six were premature births, 5 had macrosomia, and 5 had intrauterine growth restriction (IUGR). SARS-CoV-2 was detected in 1 out of 30 placental samples at delivery along with 1 out of 33 anal swabs from newborns post-delivery. No SARS-CoV-2 was detected in the maternal and anal swabs as well as in newborn rectal and gastric samples.

IgG antibodies for SARS-CoV-2 were detected in 48.8 percent of the cord samples, while IgM was not detected in the cord blood. In maternal blood, IgG was recorded to be 54% and IgM 17%.

Therefore, the current study demonstrates that most pregnant women with COVID-19 recover well with symptomatic management. However, intrauterine growth restrictions, as well as preterm births, could result due to SARS-CoV-2 infections. Therefore, pregnant women with COVID-19 must be monitored regularly. The study also reported that most pregnant women transmit IgG antibodies to the fetuses via the cord blood, which suggests a probable mechanism of fetal protection as well as passive fetal immunization against SARS-CoV-2 infection.

Limitations

The study had certain limitations. First, the sample size for the study was small. Second, all samples could not be tested due to overwhelming COVID-19 waves. Third, the finding of the study that vaginal delivery of newborns from mothers with COVID-19 is possible in most cases contrasts with the findings of other studies.

Written by

Suchandrima Bhowmik

Suchandrima has a Bachelor of Science (B.Sc.) degree in Microbiology and a Master of Science (M.Sc.) degree in Microbiology from the University of Calcutta, India. The study of health and diseases was always very important to her. In addition to Microbiology, she also gained extensive knowledge in Biochemistry, Immunology, Medical Microbiology, Metabolism, and Biotechnology as part of her master's degree.