P5355Evaluation of maternal heart rate during the first week postpartum with wearable device

Abstract

Background Throughout pregnancy and puerperium significant cardiovascular changes occur. Maternal heart rate (HR) increases from the first to the third trimester of pregnancy, with a further increase during labor. Changes in the postpartum period are less well defined, in particular, the phenomenon of postpartum maternal bradycardia (PMB). Purpose To describe the distribution of HR in the first week postpartum, the incidence of PMB and to investigate the relationship between PMB and other maternal factors such as age, BMI and type of delivery. Methods Women who gave their informed consent during a clinical evaluation in the third trimester of pregnancy, and delivered at our tertiary centre between 01/01/2018 and 30/09/2018, were included. Within 12 hours from delivery, a wrist-worn tracker with a light-emitting diode (FitBit Alta HR) was applied and then removed one week postpartum. Data were extracted as 5 minutes recordings, each showing a mean HR. Only day-time recordings were considered. PMB was defined as ratio between bradycardia recordings (mean HR<60 bpm) and all recordings >0.6. SPSS was used for statistical analysis. Results 252 women were included (mean age 35.3±5 years, BMI 23.3±5 kg/m2). 63% of women underwent caesarean section. Mean HR of the total population on day 1 after delivery was 80.7±11 bpm and then progressively decreased, with a mean HR on day 7 of 76.5±12 bpm (figure 1). 24 women developed PMB, with an incidence of 9.5%. The trend of HR in bradycardic women was opposite to that of non-bradycardic women, with an increase from day 1 (55±7 bpm) to day 7 (60.5±9 bpm) (figure 2). Device recordings during the first two days were in agreement with periodic bedside HR measurements. No bradycardic woman experienced syncope or pre-syncope or required treatment. PMB showed a positive correlation with caesarean section vs. vaginal delivery (p<0.01) and maternal age (p<0.05). No correlation was found with BMI and postpartum haemoglobin. Trend of HR in the first week postpartum Conclusion In our population the incidence of PMB identified with wearable device was 9.5% and was associated with caesarean section and maternal age. Considering that HR returned within normal limits 7 days after delivery and no woman was symptomatic, our study suggests that PMB might be considered a benign entity.