Circadian rhythm changes in ambulatory blood pressure across gestational stages associated with perinatal outcome risk in chronic hypertension

This study aimed to investigate circadian rhythm changes in ambulatory blood pressure monitoring (ABPM) across gestational stages and their associations with preeclampsia (PE) and adverse perinatal outcomes (APO) in chronic hypertension. Method A total of 107 pregnancies with chronic hypertension underwent ABPMs before 14 weeks(first) and after 20 weeks of gestation (second). Based on circadian rhythm changes across ABPMs, four groups were classified: persistent dipper (D D, n = 33),dipper to non-dipper (D-ND, n = 22), persistent non-dipper (ND-ND, n = 33), non-dipper to dipper (ND-D, n = 19). Logistic regression analyses were performed to evaluate the associations of ABPM parameters, circadian rhythm transitions with risks of PE/APO. Results The D-ND group had elevated nighttime BP changes compared to D D, ND-D showed lower nighttime BP compared to ND-ND( P < 0.05) despite more daytime BP percentage changes across ABPMs. Only in 2nd ABPM, nighttime hypertension and Non-Dipper pattern were significantly associated with PE(aOR = 5.08 and 11.51)/Maternal APO. The D-ND group had higher rates of PE(68.2%) and adverse outcomes(59.1%) compared with D D group, while ND-D had lower rates(PE 15.8%, APO 21.1%) compared with ND-ND group( P < 0.05). Across multiple adjustment models(nighttime BP, 24 h mean BP in ABPM, office BP), both D-ND and ND-ND transitions remained increased risks for PE [aOR(95%CI): 8.65 (1.89–39.67) and 7.09 (1.66–30.22)] and APO [aOR(95%CI): 8.53 (1.70–42.79) and 6.79 (1.45–31.83)] ( P < 0.05) compared with D D. Conclusion Dynamic circadian patterns changes in ABPM were associated with risks of PE/APO in pregnancy with chronic hypertension, independent of absolute BP levels.Serial ABPMs enable risk stratification for further monitoring and improving perinatal outcomes.