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821: Directed antihypertensive therapy improves growth restriction and perinatal mortality in women with chronic hypertension

      Objective

      Hypertension during pregnancy is a leading cause of morbidity and mortality for the mother and fetus. Normal maternal hemodynamic adaptations during pregnancy include increased cardiac output and decreased systemic vascular resistance. Pathologic alterations in these adaptations lead to adverse pregnancy outcomes. There are no current guidelines for determining which antihypertensive therapy to initiate in those with chronic hypertension in the first 20 weeks of pregnancy in spite of increasing evidence that the hemodynamic alterations are heterogeneous. We sought to use impedance cardiography to direct medical antihypertensive therapy in order to improve fetal outcomes.

      Study Design

      A prospective longitudinal cohort study was conducted on 961 women referred to the Maternal Hypertension Center at Cabell Huntington Hospital between 2005 and 2014 for the indication of chronic hypertension. Serial assessments of maternal hemodynamics were obtained using non-invasive impedance cardiography. Vasodilators were initiated for increased systemic vascular resistance; elevated cardiac output was treated with beta blockade.

      Results

      Blood pressure at initial visit was stratified into three groups and outcomes were compared to baseline rates of IUGR and perinatal mortality previously published by the MFMU Network. Birthweight < 10th percentile was 7.9% versus 8.8% when BP was < 140/90, 8.5% versus 12.3% when BP was 140-149/90-99, and 10.6% versus 23.7% with BP of 150-159/100-109. Perinatal mortality was 2.2% versus 3.1% when BP was < 140/90, 2.5% versus 7.2% when BP was 140-149/90-99, and 2.1% versus 10% when BP was 150-159/100-109.

      Conclusion

      Impedance cardiography directed antihypertensive therapy during early pregnancy allows for informed initiation and titration of blood pressure medications. This low cost and non-invasive test should be considered for optimizing outcomes in pregnancies complicated by maternal chronic hypertension.
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