Evidence has shown that COVID-19 is a respiratory infection, primarily transmitted person-to-person through the inhalation of contaminated droplets exhaled from the coughs and sneezes of an infected individual, although the virus can be isolated from faeces and fomites also. Healthcare providers are recommended to employ strict infection prevention and control (IPC) measures to prevent the spread of the virus; detail is available as per local Health Protection guidance.
With regard to vertical transmission (mother to baby antenatally or intrapartum), emerging evidence now suggests that vertical transmission is possible, although the proportion of pregnancies affected and the significance to the neonate has yet to be determined. Two reports have published evidence of IgM for SARS-COV-2 in neonatal serum at birth (Dong, 2020; Zeng, 2020). Since IgM does not cross the placenta, this is likely to represent a neonatal immune response to in utero infection. Previous case reports from China (Chen, 2020) suggested that there was no evidence for this and amniotic fluid, cord blood, neonatal throat swabs, placenta swabs, genital fluid and breastmilk samples from COVID-19-infected mothers have so far all tested negative for the virus.
The evidence above is all based on small numbers of cases. The situation may change and we will continue to monitor outcomes. MBRRACE-UK commenced centralised, real-time monitoring of affected mothers and their babies through UKOSS. In the interim report from UKOSS, 2.5% of babies (n = 6) had a positive nasopharyngeal swab within 12 hours of birth (Knight, 2020). In a larger systematic review of 666 neonates born to women with confirmed COVID-19, 28 of 666 (4%) neonates had confirmed COVID-19 infection postnatally. On comparing mode of birth, eight of 292 (2.7%) neonates were born vaginally, and 20 of 374 (5.3%) had a caesarean birth; seven were breastfed, three were formula fed, one was given expressed breast milk and in 17 neonates the method of infant feeding was not reported, showing that neonatal COVID-19 infection is uncommon and the rate of infection is no greater when the baby is born vaginally, breastfed or allowed contact with the mother (Walker, 2020).
In the spring of 2020, the UK Government identified pregnant women as being at higher risk of severe illness if they become infected with coronavirus and develop COVID-19, as a precautionary measure. While pregnant women are not necessarily more susceptible to viral illness, changes to their immune system in pregnancy can be associated with more severe symptoms. This decision reflects the need to restrict the spread of illness. If the number of infections were to rise sharply, the number of severely infected women could rise, and this could put the lives of some pregnant women in danger.
There is now more information on COVID-19 and its impact on pregnant women, and the way in which maternity services function. While most current research indicates that pregnant women appear to be at no greater risk of severe illness from COVID-19 than non-pregnant individuals, there may be an increased risk of pregnant women requiring admission to intensive care. As with non-pregnant individuals, women from Black, Asian and minority ethnic groups, those who are overweight or obese, and those who have pre-existing health conditions are at an increased risk of hospital admission and death.
Royal College of Obstetricians and Gynaecologists, Royal College of Midwives, Royal College of Paediatrics and Child Health, Public Health England, Public Health Scotland. Coronavirus (COVID-19) Infection and Pregnancy. Version 14. 19 February 2020.
Chen H, Guo J, Wang C Luo F, Yu X, Zhang W, et al. Clinical characteristics and intrauterine vertical transmission potential of COVID-19 infection in nine pregnant women: a retrospective review of medical records. Lancet 2020;395:809–15.
Knight M, Bunch K, Vousden N, Morris E, Simpson N, Gale C et al. Characteristics and outcomes of pregnant women admitted to hospital with confirmed SARS-CoV-2 infection in UK: national population based cohort study. BMJ 2020;369:m2107.
Walker KF, O’Donoghue K, Grace N, Dorling J, Comeau JL, Li W, et al. Maternal transmission of SARS‐COV‐2 to the neonate, and possible routes for such transmission: A systematic review and critical analysis. BJOG 2020;127(11):1324-36.