Pregnancy has not been associated with a higher risk of mortality in COVID-19. , though disease severity may be higher in the latter half of pregnancy. The risk of hospitalization and admission to intensive care is also increased in pregnancy complicated by COVID-19. COVID-19 beyond 20 weeks of pregnancy is associated with a five-fold risk of ICU admission, but very few women have required oxygen supplementation and mechanical ventilation.
The risk of preterm delivery is three-fold increased in this infection but is mostly due to medical decisions intended to improve the mother’s health. Cesarean sections are also increased in this condition. The powerful immunosuppressive action of corticosteroids has led to their deployment in the management of the ARDS associated with severe COVID-19. The RECOVERY trial showed that the potent corticosteroid dexamethasone, at a low dose of 6 mg, reduced the death rate associated with COVID-19 among those patients who required mechanical ventilation by a third. Moreover, it reduced mortality among those on supplemental oxygen by a fifth. Dexamethasone cannot be used for prolonged periods in pregnancy as it rapidly crosses the placenta and is teratogenic.
The Royal College of Obstetricians and Gynecology (RCOG) therefore recommends oral prednisolone or intravenous hydrocortisone for pregnant women with moderate to severe COVID-19, while another study prefers methylprednisolone instead. The Society of Critical Care Medicine and the European Society of Intensive Care Medicine had earlier issued its guideline on the use of intravenous methylprednisolone in ARDS, because of the improvement in this condition, spanning multiple outcomes, including healthcare use and death rate. The latter drug has been proved to be effective in acute lung injury. Moreover, it does not cross the placenta into the fetus to any significant extent. However, it is more expensive than the others, an important consideration in low-resource settings.
Methylprednisolone is concentrated to higher levels in the lungs compared to prednisolone, being more extensively distributed by volume, remaining in the lung tissues for a longer time, and being lipid-soluble. The ideal corticosteroid for the treatment of pregnancy with moderate-to-severe COVID-19 would thus distribute well in the lung parenchyma but does not cross the placental barrier significantly. If the steroid is being given to hasten fetal lung maturity, because of impending preterm delivery, a short-term course of dexamethasone or betamethasone should be given, followed by methylprednisolone.