Changes in maternal heart rate in delayed post-partum preeclampsia

Aim: Delayed-onset postpartum preeclampsia (PET) is defined as a new diagnosis of preeclampsia presenting 48 h to 6 weeks postpartum. This disorder is infrequent and associated with a higher incidence of complications as compared to antepartum PET. There seems to be a need to further characterize this disorder. The aim of the study was to investigate the difference of maternal heart rate in women with delayed onset postpartum preeclampsia as compared to healthy controls. Methods: The medical files of all women who were readmitted with delayed onset postpartum preeclampsia during 2014–2020 were reviewed. Data on maternal physiological characteristics were compared to healthy control group of women at the same post-partum day, with uncomplicated pregnancies. Results: Included 45 women with the diagnosis of delayed onset of preeclampsia at 6.3 ± 2.86 post-partum day. As compared to controls (n = 49), women with delayed post-partum were older, 34.6 ± 5.4 vs. 32.3 ± 4.7 years, p = 0.003. There were no differences between groups regarding maternal gravidity, parity, BMI (kg/m²) or Hb level at delivery day. Women with delayed post-partum preeclampsia had lower mean pulse rate as compared to controls, 58 ± 15 bpm vs. 83 ± 11.6 bpm, respectively, P < 0.0001. Only 17% of the women in the delayed onset group had pulse rate above 70 bpm as compared to 83% in the control group. Conclusions: Maternal low heart rate in cases with delayed onset of post-partum preeclampsia is an important clinical characteristic that may reflect baroreceptors response to maternal hypertension.