Evaluating The Potential For Home-Based Non-Stress Tests In The Setting Of Covid-19 Pandemic

The COVID-19 pandemic increased the frequency of telehealth prenatal visits. Transitioning to home-based NSTs administered by patients would provide antepartum testing without the need to visit a healthcare facility. However, home-based NST's are not common because of the possibility of acute intervention in the setting of a non-reassuring NST. The frequency of tests requiring acute intervention, however, is not known. This study aims to measure the frequency of tests requiring acute intervention after clinic-based NST's. A retrospective review of NST's performed at Tufts Medical Center and its affiliated institutions from 2018-2019 was performed. For each patient, we determined the indication for the NST (e.g. maternal diabetes) and collected information regarding the need for further clinical interventions (e.g. ultrasound and/or delivery) and immediate intervention. Clinical intervention was defined as a service requiring physical interaction with an experienced health care professional. Immediate intervention was defined as a clinical intervention with a timeframe of fewer than 30 minutes. Analysis of 252 pregnancies contributing to a total of 861 NST's revealed 7.2% of NST's [95% CI 5.6%, 9.1%] required further clinical evaluation. Of those, 0.8% [95% CI 0.3%, 1.7%] from separate pregnancies required immediate clinical intervention due to non-reassuring fetal testing. Immediate clinical interventions included in-patient prolonged monitoring (n=5), induction of labor (n=1), and admission to the in-patient antepartum unit (n=1). Of those who received immediate clinical care, 3 patients delivered within 24 hours of their last NST, with the earliest delivery 7.75 hours after the last NST. The proportion of patients who required further clinical evaluation after an NST was 7.2% and those who required immediate clinical intervention was 0.8%. This data is useful for patient counseling and shared decision making regarding the advisability of home-based NSTs.