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. With regard to vertical transmission (mother-to-baby antenatally or intrapartum), emerging evidence suggests that vertical transmission is possible (Dong, 2020; Zeng, 2020).
Effect on birth and the fetus
Preterm birth is the single greatest cause of neonatal morbidity/mortality in the UK and occurs in approximately 7% of pregnancies. Symptomatic COVID-19 is associated with a 17% risk of primarily iatrogenic (94%) preterm birth, which is a two- to three-times greater risk compared with non-infected pregnant women (Allotey J et al 2020).
As well as preterm birth, COVID-19 infection is also associated with an increased risk of caesarean section (59%, with approxiamtely half of these owing to maternal or fetal compromise). Of these women, approximately one in five required general anaesthesia, two-thirds of these to intubate for maternal respiratory compromise.
Aside from an increased likelihood of iatrogenic preterm birth, there is no evidence to date to implicate that COVID-19 has any adverse effects on the fetus or neonatal outcomes. Although symptomatic women are more likely to give birth before 32 and 37 weeks of gestation (adjusted odds ratio: 3.98 and 1.87, respectively).