“Impact of SARS-CoV-2 on intrapartum cardiotocography: a retrospective cohort study”

Objective: To evaluate the frequency of abnormal intrapartum CTG patterns in women infected with SARS-CoV-2. Design: Retrospective cohort study. Setting: Tertiary hospital center. Population or sample: The exposed group consisted of woman who tested positive for SARS-CoV-2. Symptomatic and asymptomatic SARS-CoV-2 infections were included. The control group consisted of randomly selected SARS-CoV-2 negative women. Method: CTG anomalies were blindly identified according to the physiological interpretation of cardiotocography traces, RCOG-classification and 3-tier system. We compared the frequency of CTG anomalies between SARS-CoV-2 positive women and controls, and between symptomatic and asymptomatic infections. Main outcome measures: Frequency of CTG abnormalities, according to the used CTG-classification systems. Results: We included 119 women in the case group, of whom 31 were symptomatic (26%), and 116 women in the control group. We found no significant differences in maternal and labor characteristics between groups. Perinatal outcomes were similar in the two groups. Major CTG abnormalities were present in 27% of cases versus 27% of controls. No significant differences between cases and controls were found using the RCOG-classification or three-tier fetal heart rate system. Abnormal patterns 1h before delivery were present during 30min (47 vs 49%) in cases and controls, respectively. CTG characteristics were similar between SARS-CoV-2 positive asymptomatic and symptomatic women, with no significant differences in the rate of abnormalities. Conclusion: Unlike suggested in earlier case-series, CTG abnormalities do not seem more frequent in maternal SARS-CoV-2 infection. No specific pattern was found in these fetuses.