Clinical implications of blood pressure variability (BPV) in pregnancies: a review

Background Hypertension disorder in pregnancy (HDP) is the second most common contributor to maternal morbidity and mortality worldwide. Blood pressure variability (BPV), with the assistance of ambulatory blood pressure monitoring (ABPM), measures blood pressure readings in pregnant women and has the potential to predict the occurrence of pregnancy-induced hypertension (PIH) or preeclampsia (PE) before any symptoms develop. Methodology Studies involving ABPM among pregnant women were identified using electronic databases such as PubMed, Scopus, Google Scholar, ScienceDirect, Medscape, Ovid and ProQuest. These electronic databases were assessed from 1990 to 2018. Keywords used to search for literatures included a combination of BPV matched with pregnancy, pregnant women and HDP, gestational hypertension and/or PE. Results Out of 21,526 articles identified, a total of 10 studies met the criteria. Seven articles used the spectral analysis method while another two articles used a combination of spectral analysis, time domain and a non-linear method for BPV analysis. The final article described BPV as vagal baroreflex. Four articles agreed that high frequency (HF) BPV was mainly dominant from the second trimester until 4 days postpartum in HDP patients. This reflects the dominant features of parasympathetic activities among these patients. Two articles that used time domain also agreed that standard deviation (SD) BPV increased in PE patients. Conclusions In pregnancy, BPV has a strong impact on the knowledge understanding of the disease in clinical fields, allows a superior ability to predict PIH and PE in mid-pregnancy and offers potential value for addressing hypertension in pregnancy.