key: cord-1003158-bf1q4k6t
authors: Bouchghoul, Hanane; Vigoureux, Solene
title: Do pregnant women have protective immunity against COVID‐19?
date: 2020-06-24
journal: BJOG
DOI: 10.1111/1471-0528.16342
sha: a9613ca055614bccaa4a03a34cafe9103e8facbf
doc_id: 1003158
cord_uid: bf1q4k6t

nan

The current epidemic caused by the highly contagious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its rapid spread globally is of major concern. Pregnant women could constitute a vulnerable population.

We read with interest the article COVID-19 in pregnancy by Jim G. Thornton, in which the author relates that coronavirus disease 2019 (COVID-19) is less severe in pregnancy than the two previous coronavirus infections, SARS and Middle East respiratory syndrome. 1 We fully agree with the author and would like to make some assumptions for a less frequent and severe disease in pregnancy.

Lower rates of SARS-CoV-2 among pregnant women have been reported in different surveys published around the world (USA, China, Italy) and is probaby due to several factors: pregnant women are younger and therefore are less likely to have typical symptoms; but are also admitted usually for labour and delivery and not because of SARS-CoV-2 symptoms, so are less tested.

Furthermore, as SARS-CoV-2 infection can activate innate and adaptive immune responses with severe consequences, pregnant women could be preserved by the state of immunomodulation during pregnancy.

In pregnancy, progesterone has immunomodulatory properties allowing maternal tolerance of the fetus and so can impact many immune pathways involved in autoimmune disease and immune-mediated injury. 2 During pregnancy, there are increased circulating levels of antiinflammatory molecules interleukin-1 receptor antagonist (IL-RA) and soluble tumour necrosis factor-a receptor (TNF-R), along with decreased IL-1b and TNFa. 2 Autoimmune diseases like rheumatoid arthritis and multiple sclerosis remit during pregnancy.

In the most severe SARS-CoV-2 infections we report uncontrolled inflammatory innate responses and impaired adaptive immune responses that may lead to harmful tissue damage, both locally and systemically. Progression to acute respiratory distress syndrome is associated with the increase of pro-inflammatory cytokines and chemokines, known as cytokine release syndrome. 3 A cytokine profile has been reported in most severe SARS-CoV-2 infections, characterised by increased levels of cytokines and chemokines.

In a systematic review of the available literature including six studies with 51 pregnant women, 4 the outcome has been generally favourable for both mothers and fetuses. In their review, women have been most often delivered by caesarean section, and frequently before term gestation. As in patients infected with SARS-CoV-2, the serious complication is acute respiratory distress syndrome and ventilation of the mother may be difficult in the third trimester of pregnancy; it is certainly possible that the decision to delivery by an elective caesarean section was influenced by the understandable anxiety towards the potential consequences. &

COVID-19 in pregnancy

Progesterone and autoimmune disease

COVID-19: consider cytokinestormsyndromesandimmunosuppression

COVID19 during pregnancy: a systematic review of reported cases