1. Introduction
Coronaviruses are spherical, enveloped, and the largest of positive-strand RNA viruses. They have a wide host range, including birds, farm animals, pets, camels, and bats, in which they primarily cause respiratory and gastrointestinal disease. Belonging to the order Nidovirales, family Coronaviridae, and the subfamily Orthocoronaviridae there are four genera of coronaviruses—Alphacoronavirus, Betacoronavirus, Deltacorona virus, and Gammacoronavirus [1,2,3,4].
In humans, they are a cause of mild illnesses including the common colds occurring in children and adults, and were believed to be of modest medical importance. However, two zoonotic coronaviruses—including the severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV)—can produce severe lower respiratory tract infections. Both the SARS-CoV and MERS-CoV have several features in common that are factors in producing nosocomial transmission, replication in the lower respiratory tract, and viral immunopathology. Both coronaviruses are zoonotic infections and constitute significant public health threats that have resulted in epidemics with significant loss of life [1,5,6]. When the SARS-CoV and MERS-CoV infect women who are pregnant, they can result in poor obstetric outcomes including maternal morbidity and death. There are currently no vaccines or specific treatments approved for coronavirus infections [2,6].
Prior to December 2019, there were a total of six coronavirus species that produced human infection: HCoV-229E and HCoV-NL63 belonging to the Alphacoronavirus genus; and HCoV-OC43, HCoV-HKU1, MERS-CoV, and SARS-CoV, which belong to the Betacoronavirus genus [1,2]. As of December 2019, there are now seven species that infect humans.
As the newly identified novel coronavirus, termed 2019-nCoV and subsequently named SARS-CoV-2, spreads rapidly throughout China and across to other countries, researchers scramble to understand transmission dynamics, virulence, and pathogenicity. Given the rapidly progressive spread of this current 2019 novel coronavirus it is reasonable to expect that pregnant women have already become infected. The effect of 2019-nCoV during pregnancy is, at the present, unknown. This communication reviews the medical and clinical findings from coronavirus infections in pregnant women in order to anticipate how the newly discovered 2019-nCoV might affect maternal and infant morbidity and mortality.