Nighttime Arterial Pressure Phenotypes and Their Prognostic Value in Pregnant Women as Predictors for Future Maternal and Neonatal Events

Objective: We have previously demonstrated that some ambulatory blood pressure monitoring (ABPM) values can predict maternofoetal evens in hypertensive pregnant women. The analysis of the different nighttime blood pressure (BP) phenotypes in pregnant women is still an unknown topic. Design and method: A retrospective cohort study which followed a sequential number of 274 hypertensive pregnant patients (mean age of 32 years) from 2007 to 2022, who underwent ABPM made with a Spacelabs 90207. Data was collected and analysed in SPSS Statistics through different parametric tests. Nocturnal BP phenotypes were defined for both systolic and diastolic values as: reverse dipper (RD); non-dipper (ND); dipper (DP); and extreme dipper (ED). An event was defined as the composite endpoint of multiple adverse events: preeclampsia or eclampsia, foetal or neonatal death, prematurity, low weight at birth, gestational diabetes, and maternal death. Results: A Kaplan-Meier survival curve analysis was performed between systolic DP and ND groups, with ND showing a worse survival with a long rank of 11.331 (p<0.001); and for diastolic DP and ND groups, again with ND showing a worse survival with a long rank of 15.335 (p<0.001). In a further systolic nocturnal phenotypes Kaplan-Meier analysis, RS (n=6) showed the worse survival, followed by ND (n=87), while DP (n=162) and ED (n=19) showed better survival, with a log rank of 8.4 (p=0.038). For the diastolic nocturnal phenotypes Kaplan-Meier analysis, ND (n=33) showed the worse survival, followed by DP (157), while ED (81) showed better survival, with a log rank of 21.3 (p<0.001). Diastolic RD showed no events, likely due to the small sample size (n=3). (Fig 1) Conclusions: This study further exemplifies the importance of ABPM in the evaluation of hypertensive pregnant women, both for its major role in diagnosis as well as prognostic value. Different nocturnal phenotypes show different survival rates, and patients without systolic or diastolic dipping seem to be at a major risk.