///2016 Abstract Details
2016 Abstract Details2019-07-15T10:10:51-05:00

The Prone Position in Preeclampsia (P3) Study

Abstract Number: T-48
Abstract Type: Original Research

Alicia T Dennis MBBS PhD PGDipEcho FANZCA1 ; Liesel Hardy MD2; Liz Leeton BSc3

Introduction:The prone position, achieved using appropriate pillows, is a safe position for pregnant women. It is utilised in allied health fields & for relaxation & massage in pregnancy. In this position uterine compression of large abdominal vessels is significantly reduced. In non-pregnant critically ill adults respiratory mechanics are also improved. Despite these advantages, the prone position is rarely used in medical settings in pregnancy. There is little information about the position in pregnancy & no published information about the prone position in preeclampsia(PE). Recently a new unified theory of PE has been published.1 It proposes that hypertension in PE is an adaptive response to the demands of a growing fetus & is driven by an imbalance between maternal oxygen supply to the fetus (which may be caused by inadequate blood flow to the uteroplacental unit) & fetal oxygen demands. We hypothesise that placing a women with PE in the prone position will reduce her blood pressure(BP) by eliminating abdominal compression of blood vessels thereby reducing abdominal vascular resistance & improving blood flow. We aimed to test this hypothesis & assess feasibility of the prone position in pregnancy.

Method:After IRB approval, consent & trial registration (ACTRN:12615000160538) 62 women(50 healthy term pregnant(HP) & 12 PE) had their BP, heart rate(HR), oxygen saturation(SpO2), respiratory rate(RR), fetal HR(FHR) & comfort levels measured in 2 positions: left lateral, & prone. Measurements were after 5 minutes rest in each position. Sample size(12) PE group was based on a clinically important 10 mmHg change in systolic BP from lateral to prone position(power 80%,5% type 1 risk,two tailed t-test).

Results:62 women completed the study. All found the prone position acceptable. Mean±SD age, gestation & body mass index for HP women was 33±4.1 years, 38±1.0 weeks and 27±3.2 kg.m-2 & for PE women was 31±3.7 years, 36±3.7 weeks, 32±5.9 kg.m-2 respectively. 44% HP & 50% PE women preferred the prone position to lateral. Hemodynamic & respiratory variables are shown in the table.

Conclusions:The prone position is feasible & comfortable in pregnant women including those at term. The prone position may reduce SBP in women with PE without obvious adverse effects & may be an acute treatment for PE. Randomised controlled trials are needed. Pregnancy should not be a contraindication to the prone position.

Reference:1. Dennis A,Castro J. Anaesthesia 2014;69:1183-1189

SOAP 2016