Oral Presentation Society of Obstetric Medicine of Australia and New Zealand and Australasian Diabetes in Pregnancy Society Joint Scientific Meeting 2017

Non-invasive study of haemodynamic parameters in normotensive versus hypertensive pregnancies (#35)

Jade Martyn 1 , Franziska Pettit 2 3 , Jack Mangos 1 , Rachel Preece 4 , Mark Brown 2 3 , Amanda Henry 5 6
  1. University of New South Wales, Sydney, NSW, Australia
  2. Department of Renal Medicine , St George Hospital , Sydney , NSW, Australia
  3. Department of Medicine, University of New South Wales, Sydney , NSW, Australia
  4. Department of Renal Medicine , Bathurst Base Hospital , Bathurst, NSW, Australia
  5. School of women and children's health, UNSW medicine, Sydney , NSW, Australia
  6. Department of Women and Children's Health , St George Hospital , Sydney , NSW, Australia

Background/Objectives: Major cardiovascular system physiological changes during pregnancy include decreased systemic vascular resistance (SVR) and increased cardiac output (CO). In hypertensive disorders of pregnancy, especially preeclampsia, these usual cardiovascular adaptations maybe deficient. This study aims to evaluate differences in cardiac function and haemodynamic parameters using point-of-care, non-invasive testing, in non-pregnant women, and in women with normotensive and hypertensive (chronic hypertension, CH, preeclampsia, PE gestational hypertension, GH) pregnancies.

 

Methods: Non pregnant (NP, n=33), normotensive (NT, n=73) and hypertensive (HT, n=57; 21 CH, 16 GH, 20 PE) pregnant women aged 18-45 with a singleton pregnancy studied cross-sectionally from 20 weeks’ gestation in this ongoing prospective study. Haemodynamic parameters were obtained non-invasively via the Ultrasound Cardiac Output Monitor (USCOM) and liquid crystal sphygmomanometer. Women are followed prospectively and pregnancy outcomes, including preeclampsia development, ascertained.

 

Results: There was no statistically significant difference in average stroke volume (79mL/NP, 74mL/NT, 70mL/CH, 78mL/GH, 73mL/PE; p=0,67), cardiac output (5.5/5.9/5.8/6.0 and 5.7L respectively; p=0.75) and cardiac output index (3±0.6 versus 3±0.9 versus 3±0.8 versus 3±0.9 versus 3±1L/min/m2; p=0.084) between groups. Preeclamptic pregnancies had significantly higher SVR (1851±1111 versus 1204±381 dyne/se/cm-5; p≤0.001) and systematic vascular resistance index (3653±2189 versus 2231±887dyne/sec/cm-5/m-2; p≤0.001) than NT pregnancies. As expected, HT participants had significantly higher mean arterial pressure, systolic (109±9mmHg NP,110±12 NT,129±10 CH,130±11 GH,138±12 PE; p≤0.001) and diastolic blood pressure (67±7, 69±9, 79±9, 81±9, 87±12mmHg respectively; p≤0.001) than NT or NP.

 

Conclusions: In this pilot study of non-invasive (USCOM) haemodynamic measurements, significant differences in systemic vascular resistance, but not overall cardiac output, were seen between normotensive and hypertensive pregnancies. A larger sample size is needed for further investigation, including determining whether USCOM may be useful in predicting which pregnancies will progress from gestational hypertension and/or chronic hypertension, to preeclampsia.