Prenatal transmission of severe acute respiratory syndrome coronavirus 2, resulting in neonatal severe acute pneumonia, from an asymptomatic mother: a case report

In June 2021, a 22-year-old woman (gravida 1, para 1, no history of diabetes, hypertension, sickle cell disease, or any other disease, no surgical history) was admitted to our institution at 38 weeks gestation for labor. The patient was not vaccinated against SARS COVID-19. The prenatal course was uncomplicated. Ultrasound surveillance results at 25, 28, and 32 weeks were normal. She tested negative for toxoplasmosis, other infections (syphilis, varicella-zoster, parvovirus B19), rubella, cytomegalovirus (CMV), herpes (TORCH), human immunodeficiency virus (HIV), and hepatitis B. She tested positive for group B streptococcus vaginal infection and was treated according to French guidelines. She was afebrile and asymptomatic with normal vital signs throughout pregnancy. The duration of water break was less than 12 h. Four days before delivery, she routinely tested positive for SARS-CoV-2, without any symptoms.

A live-born female infant was delivered vaginally. The resuscitation and newborn APGARs were 10 and 10 at 1 and 5 min, respectively. Birth weight was 2670 g (18th percentile), length was 49 cm (63rd percentile), and head circumference was 32 cm (10th percentile), all appropriate for gestational age. The patient’s physical status at birth was unremarkable. At minute 11 of life, she presented with respiratory distress (tachypnea, nasal flaring, chest retractions, grunting, and saturation of 90%) requiring noninvasive ventilation. The Silverman index was 3. Peripheral pulses were well perceived, and there was no heart murmur. The rest of the physical examination results were unremarkable. Arterial blood gas (ABG) showed pH 7.30, PCO₂ of 60 mmHg, PaO₂ of 65 mmHg, and HCO ₃ ^– of 20 mmol/L. Thirty minutes after delivery, the neonatal nasopharyngeal swab was positive for SARS-CoV-2 real-time polymerase chain reaction (RT-PCR), and immunoglobulin (Ig)-M and IgG for SARS-CoV-2 were negative. Neonatal isolation was implemented immediately after birth without mother–neonate skin-to-skin contact. At minute 12 of life, she was transferred to the neonatal intensive care unit (ICU) to continue noninvasive ventilation and explore for respiratory distress. At 30 min, chest radiography revealed bilateral opacities consistent with respiratory distress syndrome (Fig. 1). Intravenous penicillin plus gentamycin antibiotics were started and stopped after 5 days, as blood cultures, cerebrospinal fluid remained negative, and C-reactive protein (CRP) levels were low. On the 6th day of life, faced with the persistence of the respiratory distress, a thoracic computed tomography (CT) scan was performed, showing bilateral parenchymatous lesions (10–20%) in ground glass, compatible with a COVID-19-type infection (Fig. 2). At the same time, the neonate showed signs of multiple organ failure (elevated liver and cardiac enzyme levels). The liver enzymes alanine transaminase (ALT), aspartate transaminase (AST), and lactate dehydrogenase (LDH) were 60 IU/L, 540 U/L, and pro-BNP > 350 ng/L, respectively (Table 1). No signs of coronary artery dilation were observed on echocardiography. She was treated with azithromycin (20 mg/kg/day) for 5 days. All the signs recovered fully by day 12. Results of repeated neonatal PCR sampling were positive on days 1, 3, 10, and 18. Inflammatory tests (CRP, Pro-BNP, and LDH), as well as blood gas performed at 2 weeks of age, were strictly normal. She was discharged 30 days after birth, with a plan for close follow-up by her pediatrician. The COVID-19 RT-PCR test result was negative on day 30. At the 3-month follow-up, the infant was breastfeeding well with no fever or respiratory distress. Six months later, mother and baby were doing well. Our patient has been followed for 6 months and has normal growth. She is now 2 years old and developing well, with no sequelae.