Method
This study is a prospective cohort study conducted in Arash women’s hospital, a university hospital affiliated with Tehran University of Medical Sciences.
This study has been approved by the Ethics Committee of Tehran University of Medical Sciences (IR.TUMS.VCR.REC.1398.1057).Written consent was obtained from all participants.
In this study, all pregnant women who were hospitalized in Arash Hospital from March 1 to April 20 2020 were evaluated in terms of inclusion and exclusion criteria. Inclusion criteria were all pregnant women who had been hospitalized in our hospital during the study period and were willing to participate in the study.
Based on the presence or absence of clinical signs or symptoms of covid-19 infection, women were divided into two general categories: One group whose participants had clinical signs and symptoms of the virus and the other group who did not show any clinical signs and symptoms. Clinical symptoms have included fever, dry and progressive cough, tachypnea , shortness of breath, decreased oxygen saturation and fatigue. Reverse transcriptase–polymerase chain reaction for Covid-19 nucleic acid (Covid-19 PCR) test of nasopharyngeal swabs and Chest Computed Tomography (CT) scan were performed for the group with clinical symptoms. Women with positive Covid-19 PCR test were classified as confirmed group. In cases with negative Covid-19 PCR test, if they had very typical clinical symptoms verified by an infectious disease specialist, considering the false negative probability of Covid-19 PCR test and high diagnostic sensitivity of CT scan finding(6, 7), positive findings of CT scan have been considered as a criterion utilized as a tool to confirm the infection. These findings in chest CT scan included ground-glass opacity, consolidation, reticulation/thickened interlobular septa and nodules(6).
Women with negative results of both CT scan and Covid-19 PCR test who had typical clinical symptoms were considered as a potentially infected (probable group) if they had two or more of the laboratory findings including: leukocytosis (white blood cell count >11×109/L), lymphopenia(lymphocyte count <1.0×109/L;),thrombocytopenia , increased C-reactive protein (CRP)(≥10 mg/d).Women with clinical symptoms were excluded from the study in case Covid-19 PCR test and CT scans finding were negative and no laboratory findings were found. Women who did not have any clinical signs or symptom of infection were considered as a control group.
The exclusion criteria for confirmed group were positive CT scan finding in women with mild or transient symptoms in the absence of typical clinical symptoms. The exclusion criteria for probable group were presence of only one paraclinical finding or the presence of only mild and transient clinical symptoms.
In our hospital, universal screening is not performed for all inpatients and since some of affected people may be asymptomatic(8), in order to minimize the presence of asymptomatic individuals in the control group as much as possible, we implemented precise exclusion criteria. So exclusion criteria for control group included: A history of any suspicious symptoms of the virus over the past two weeks, contact with Covid-19 virus infected or suspected individuals within the last 14 days, any suspicious clinical symptoms of the virus over the last two weeks in their family members, attendance in crowded areas such as shopping malls and parties over the past 14 days, going to hospitals or clinics for any reason within the last 14 days except for the time of current hospitalization.
All pregnant women who were hospitalized during the study period were screened according to the above inclusion and exclusion criteria.
Confirmed and probable infected women were treated according to the protocols of the World Health Organization. All other managements and procedures in three groups were performed based on obstetrics indications and our hospital protocols. Given the lack of strong evidence according to perform cesarean section (CS) in women infected by the virus, our hospital’s protocol was choosing delivery method based on other obstetrics indications. So we didn’t impose CS on women because of corona virus infection. It’s worth mentioning that, in our hospital, women give birth in separate rooms during childbirth, and during this epidemic, we have decided to avoid using common tools such as birth balls as much as possible and also doctors, residents, and midwives who take care of each patient are specific for the same patient and do not take care of different patients at the same time as well as use of complete personal protective equipment.
Babies born to infected mothers underwent early cord clamping and early temporary separation from their mothers immediately after birth and Covid-19 PCR test was done via their nasopharyngeal and throat within the same hour after birth.