Longitudinal changes in vascular function parameters in pregnant women with chronic hypertension and association with adverse outcome: a cohort study

OBJECTIVES: Raised vascular function measures are associated with development of adverse maternal and perinatal outcomes in low risk pregnancy. This study aimed to evaluate the association between longitudinal vascular function parameters and adverse outcomes in pregnant women with chronic hypertension.

METHODS: Pregnant women recruited to the PANDA (Pregnancy And chronic hypertension: NifeDipine vs lAbetalol as antihypertensive treatment) trial in three UK maternity units had serial pulse wave analyses performed using the Arteriograph® (Tensiomed, Budapest, Hungary) while in a sitting position from 12 weeks onwards. Statistical analysis used random-effects logistic regression models and compared those who developed superimposed pre-eclampsia (SPE) to those who did not, women who delivered a small for gestational age infant (<10th birthweight centile) (SGA10) to those who delivered an infant with birthweight >10th centile, and women of Black ethnicity with women of non-Black ethnicity.

RESULTS: The cohort included 97 women (90% (n=87) randomised to antihypertensive treatment), with up to six longitudinal vascular function assessments (mean 3), (57% (n=55) of Black ethnicity) with chronic hypertension and singleton pregnancies. SPE was diagnosed in 18% (n=17) and 30% (n=29) of infants were SGA10. In women who developed subsequent SPE compared to those who did not, mean brachial systolic blood pressure (SBP) (148 vs 139 mmHg; p=0.002), mean diastolic blood pressure (DBP) (87 vs 82 mmHg; p=0.01), mean central aortic pressure (139 vs 128 mmHg; p=0.001) and mean augmentation index (AIX-75) (29 vs 22%; p=0.01) were significantly higher across gestation. Mean brachial SBP (146 vs 138 mmHg; p=0.001), mean DBP (86 vs 82 mmHg; p=0.01), mean central aortic pressure (137 vs 127 mmHg; p=<0.0001), and mean PWV (9.1 vs 8.5 m/s; p=0.02) were higher across gestation in women who delivered an SGA10 infant compared to women who delivered an infant with birthweight >10th centile. No longitudinal differences were found in the vascular function parameters in women of Black ethnicity compared to non-Black ethnicity.

CONCLUSION: There are persistent differences in vascular function parameters and brachial blood pressure through pregnancy in women with chronic hypertension who later develop adverse maternal and perinatal outcome. Further investigation of the possible clinical use of these findings is warranted.