Childbirth is the most common reason for hospitalization in the United States (3.9 million/year).1,2 The prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among patients admitted for labor and delivery is between 0% and 15.4%; most patients are asymptomatic.3–5 The extent of SARS-CoV-2 environmental contamination during childbirth is not known. Coughing, speaking, vomiting, and breathing have all been shown to generate aerosols and droplets.6 Expiratory forces are increased during active labor. In addition, the second stage of labor often results in significant fecal contamination, which has been associated with SARS-CoV-2 detection in surface and aerosol samples.7 We aimed to evaluate SARS-CoV-2 environmental contamination in the labor and delivery environment and on personal protective equipment to provide preliminary data as a foundation for future research and guidance for continued protection of health care workers.
We conducted this study at a single academic institution from March 2020 to June 2020. The protocol was approved by the Oregon Health & Sciences University Institutional Review Board. Universal SARS-CoV-2 polymerase chain reaction testing occurred for all patients admitted to the labor and delivery unit. Environmental swabs were collected from room surfaces and health care workers’ face shields. In addition, passive and active air samples were collected. Reverse transcription polymerase chain reaction targeting the spike gene was used to detect SARS-CoV-2 RNA (see Appendix 1, available online at http://links.lww.com/AOG/C57).
We obtained samples for two vaginal and two cesarean births (four asymptomatic patients who tested positive for SARS-CoV-2). General anesthesia was not used for any of these four deliveries. Patients were unable to consistently wear masks during vaginal birth 2 and cesarean birth 1.
In baseline empty room samples, viral RNA was detected in 3 of 45 (6.7%) surface swabs and 1 of 23 (4.3%) passive air samples. After delivery, the total proportion of positive samples increased for both surface swabs (8/45, 17.8%) and passive air samples (5/23, 21.7%) (Table 1). The greatest change from baseline was after vaginal birth 2 (negative pressure room). After vaginal birth 2, the majority of the passive air settling dishes tested positive (four of five). Three of these positive settling dishes were located more than 6 feet from the patient bed.
Postdelivery active air sampling results were not consistent by delivery type. No viral RNA was detected by active air sampling before or after cesarean birth 2, whereas it was detected after vaginal birth 2 (14.4 gene copies/L air) and cesarean birth 1 (4.80 gene copies/L air).
Postdelivery face shield sampling results also varied by delivery type. SARS-CoV-2 RNA was not detected on any face shield (surgeons, anesthesiologist, or nurses) after either cesarean birth. The health care worker personal protective equipment for vaginal birth 1 was not obtainable. All health care worker face shields were positive for SARS-CoV-2 RNA after vaginal birth 2 (Fig. 1).