“Impact of SARS-CoV-2 on intrapartum cardiotocography: a retrospective
cohort study”
Abstract
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 <10min (29 vs
31%), 10-30min (24 vs 20%) and >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.