RESULTS
A total of 22 articles were shortlisted for addition into the final manuscript. The PRISMA flow diagram of study selection at all stages can be visualized in Figure 1. Two of the full texts were excluded due to wrong population: discussing Middle Eastern Respiratory Syndrome (MERS) and eight articles were excluded because they were either editorials or commentaries.
The accepted articles can be visualized in Table 1 below. NOS measures the risk bias and quality of the cohort and case control manuscripts on bases of three variables: selection (scored out of 4 stars, represented in the first row of table), comparability (scored out of 2 stars, represented in the second row of the table) and exposure (measured out of 3 stars, represented in the third row of the table). A score of 7 or more is expected to be a good score. MQC measures the quality of methodology using selection (scored out of one plus sign), ascertainment (scored out of 2 plus signs), causality (scored out of 4 plus signs), and reporting (scored out of 1 plus sign). A score of 6 or more was considered a good score. AMSTAR score was used in reviewing the methodology of included systematic reviews. AMSTAR marks on 11 components with yes, partial yes and no. To make the evaluation brief, these three scores are grouped together and the final score is given in the table. The guidelines were not evaluated because of the exhaustive process and time constraints. Perspective reports and technical documents were subjectively screened for risk bias assessment.
The demographics of patients in terms of trimester of pregnancy in which diagnosis is made, the geographical location of patient(s) and symptoms warranting screening and testing are included in the studies are shown in Table 2 . A total of 403 pregnancies were considered in the study with most of the patients in the third trimester of pregnancy. Due to high volumes of data from China, most of the studies either originates from mainland China or are published by Chinese authors. In the cohort sampled, there was no maternal mortality reported and only 6 different fetal mortalities have been reported by Schwartz et al, Zaigham et al, Panah et al and Mullins et al. of which there was 1 intrauterine, 1 still birth and the other 4 neonates expired shortly after birth14-17.