The Effect of Left Uterine Displacement During Caesarean Delivery on Maternal and Neonatal Outcomes: A Systematic Review & Meta-analysis

The Effect of Left Uterine Displacement During Caesarean Delivery on Maternal and Neonatal Outcomes: A Systematic Review & Meta-analysis | Authorea try { document.documentElement.classList.add('js'); } catch (e) { } var _gaq = _gaq || []; _gaq.push(['_setAccount', 'G-8VDV14Y67G']); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); })(); Skip to main content Preprints Collections Wiley Open Research IET Open Research Ecological Society of Japan All Collections About About Authorea FAQs Contact Us Quick Search anywhere Search for preprint articles, keywords, etc. Search Search ADVANCED SEARCH SCROLL This is a preprint and has not been peer reviewed. Data may be preliminary. 23 January 2026 V1 Latest version Share on The Effect of Left Uterine Displacement During Caesarean Delivery on Maternal and Neonatal Outcomes: A Systematic Review & Meta-analysis Authors : Unyime Ituk 0000-0003-0304-7894 [email protected] , Michelle Bremer Gama N , Rawan Hassanain , and Rakesh Sondekoppam V Authors Info & Affiliations https://doi.org/10.22541/au.176916075.59902476/v1 497 views 120 downloads Contents Abstract Supplementary Material Information & Authors Metrics & Citations View Options References Figures Tables Media Share Abstract Background: Left uterine displacement (LUD) during caesarean delivery (CD) is widely recommended to prevent aortocaval compression and improve maternal haemodynamic and neonatal outcomes. However, prior Cochrane review conducted a decade ago found limited evidence supporting LUD’s efficacy. Objective: To evaluate the impact of LUD on maternal haemodynamic state, vasopressor requirements, and neonatal outcomes during CD Search Strategy: MEDLINE, EMBASE, CINAHL, and Cochrane Central Register of Controlled trials (CENTRAL) from January 1966 to August 2025. Selection Criteria: Randomized controlled trials comparing LUD + supine versus supine position during CD. No language restrictions. Data Collection and Analysis: Using PRISMA guidelines two reviewers independently screened studies, extracted data and assessed risk of bias. A random effects model was used for meta-analysis to estimate pooled odds ratios with 95 % confidence intervals. The protocol was registered on the International Prospective Register of Systematic Reviews (PROSPERO: CRD42023408564). Main Results: Seven studies (666 patients) met inclusion criteria. Pooled data showed no significant differences between LUD + supine versus supine groups for the primary outcome of the incidence of hypotension (OR 0.51, 95% CI: 0.24 to 1.06) or umbilical artery pH (MD (95%CI): 0.01 (-0.01 to 0.02). Maternal systolic or mean blood pressure, incidence of nausea/vomiting or vasopressor requirements did not show significant differences nor did any other neonatal outcomes, including APGAR scores. Conclusion: Left uterine displacement does not significantly impact maternal haemodynamic state, vasopressor use, or neonatal outcomes in the current obstetric anaesthesia practice. Routine LUD application during CD should be reconsidered. INTRODUCTION Landmark studies demonstrated that, in the third trimester of pregnancy, the enlarged uterus causes aortocaval compression, reducing venous return and leading to supine hypotension syndrome[1-3]. Subsequent studies examining the effects of maternal positioning during caesarean delivery (CD) found that a 15-degree left uterine displacement was associated with reduced maternal cardiovascular instability and more favorable fetal acid–base status[4,5]. These findings led to the widespread adoption of left uterine displacement (LUD)—achieved by tilting the operating table or placing a wedge under the right pelvis—as a standard practice during caesarean delivery. Currently, it is recommended that a LUD be performed after induction of anaesthesia in all women having CD with a goal of improving maternal haemodynamics and uteroplacental blood flow[6]. However, a Cochrane systematic review and meta-analysis on maternal positioning during CD that was conducted in 2013 reported limited evidence to support the use of any of the studied maternal positions including LUD. As there was only 1 study confirming the benefit of LUD in decreasing maternal hypotension the authors concluded that larger well designed studies are needed to determine the benefits and risks of each position.[7] Furthermore, the review did not assess the impact of LUD on vasopressor requirements during CD. Since the publication of the review there have been further studies investigating the effect of LUD during CD. Therefore, we performed this systematic review and meta-analysis to reexamine the evidence regarding efficacy and benefits of LUD during CD. METHODS This systematic review and meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic review and Meta-Analysis (PRISMA) guidelines. Details of the protocol for this review were registered on PROSPERO (CRD42023408564) and can be accessed at https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023408564 . Eligibility criteria, source of information, search and study selection A systematic literature search was performed in MEDLINE, EMBASE, CINAHL and Cochrane Central Register of Controlled trials (CENTRAL) databases to identify randomized clinical trials that assessed the efficacy of LUD on maternal haemodynamics and neonatal outcomes during CD. We included randomized controlled trials in women ≥ 18 years of age having CD who were randomized to either a left lateral tilt position of the operating table or a wedge placed under the right hip/pelvis to achieve a LUD compared to a supine position after initiation of anaesthesia. The search was restricted to studies published between January 1966 and August 2025 with no language restrictions. The bibliographies of retrieved articles were also searched to identify additional studies. Abstracts, reviews, letters to the editors, retrospective studies and case reports were excluded. The term ‘caesarean section’ was combined with ‘patient positioning’ and its variations (Appendix S1). Rayyan, a web-based application (https://new.rayyan.ai) was used to screen and deduplicate retrieved studies. Two reviewers (MBG and RH) independently screened each study for eligibility. Any disagreement in eligibility were resolved after discussion with a third reviewer (UI) Risk of bias assessment The eligible articles were assessed independently by two reviewers (MBG and RH) using the Cochrane Risk-of-Bias Tool for Randomized Trials to assess bias. The criteria evaluated were random sequence generation, allocation concealment, blinding of participants, blinding of outcome assessment, incomplete outcome data, selective reporting bias, and other sources of bias. Any discrepancies in risk of bias assessment were resolved by discussion with a third reviewer (UI). Due to insufficient number of studies, we did not perform a publication bias assessment of the included trials. Data collection process and data items A standardized data entry form was used by two reviewers (MBG and RH) to extract data independently from the retrieved articles. Data extracted included: first author and publication year, study design, anaesthetic technique, number of patients included, primary outcome of the study, secondary outcomes of the study; maternal systolic and mean arterial blood pressure, incidence of hypotension, vasopressor requirement, intraoperative nausea and vomiting, foetal umbilical arterial blood gas, and APGAR scores. Authors of data reported only in graphs were contacted, if no response was received the reviewers extracted data from the graph using the WebPlot Digitizer software (https://plotdigitizer.com/). Any discrepancies in extracted data were resolved by discussion with a third reviewer (UI). Primary outcomes were incidence of maternal hypotension as defined by the trials and foetal umbilical artery pH. Secondary outcomes included maternal SBP at 5 and 15 minutes after initiation of anaesthesia, maternal vasopressor requirements, maternal intraoperative nausea and vomiting, foetal umbilical artery base excess, and APGAR scores at 5 minutes after birth. For the purpose of analysis, in studies where patients received ephedrine, the dose was converted to the phenylephrine equivalent using a relative potency ratio for phenylephrine: ephedrine of 80:1[8] to calculate the total vasopressor requirements. Analyses and synthesis of results A random-effects model meta-analysis was planned for all outcome measures due to inherent methodological differences anticipated in studies due to treatment protocol, anaesthesia techniques or demographic differences. For dichotomous data, we presented results as summary risk ratio (RR) with 95% confidence intervals (CI) and for continuous data, we used the mean difference (MD) with 95% CI. A 2-sided P-value ≤ 0.05 was considered statistically significant. We assessed statistical heterogeneity in each meta-analysis using the T 2 , I 2 and Chi 2 statistics. We regarded heterogeneity as substantial if I 2 was greater than 50% and either T 2 was greater than zero, or there was a low P value (less than 0.10) in the Chi 2 test for heterogeneity. The Review Manager (RevMan 8.9) software (www.revman.cochrane.org) was used for statistical analysis. RESULTS A total of 3129 studies were identified that fulfilled our initial search strategy. After deduplication and manual screening, 7 studies with a total of 666 patients were included in the final analysis (figure 1). Five studies (381 patients) used spinal anaesthesia for CD (190 patients had LUD and 191 with no LUD)[9-13], one study with 80 patients used combined spinal epidural anaesthesia for CD (40 patients had LUD and 40 did not)[14], and the final study with 204 patients (103 patients had LUD and 101 did not) did not standardize the anaesthesia technique (177 patients received general anaesthesia and 27 spinal anaesthesia) [15]. A summary of included studies is reported in Appendix S2. Quality of studies All included studies used either computer block randomization, random number table or ballot method of randomization for group assignment. Matorras et al. and Iqbal et al. did not state how allocation concealment was maintained. Due to the nature of the intervention (left uterine displacement) the surgeon and anaesthesiologist caring for the patients were unblinded. Chungsamarnyart et al. and You et al. were the only included studies that had outcome data assessors blinded to group assignment. The methodological quality across all included studies presented as percentages is reported in figure 2 and risk of bias summary of each included study is reported in figure 3. Maternal haemodynamics The incidence of maternal hypotension was reported in 4 studies[9,11,13,14], figure 4. Pooled results did not show statistically significant difference in the incidence of maternal hypotension (odds ratio 0.51, 95% CI, 0.24 to 1.06, I 2 , 53%). Five studies [9,10,12-14] reported on systolic blood pressure (SBP) readings at 5 minutes post-spinal and three studies [10,11,13] reported SBP at 15 minutes post-spinal. Pooled results for SBP showed no statistically significant difference between the groups at 5 minutes (mean difference 2.90, 95% CI, -2.62 to 8.42, I 2 , 81%), figure 5; or at 15 minutes following the spinal (mean difference 2.15, 95 % CI, -3.52 to 7.81, I 2 , 71 %), figure 6. Mean arterial pressures (MAP) at 5 minutes post-spinal were recorded by three studies [12-14] with no statistically significant difference (mean difference -0.30, 95 % CI, -5.68 to 5.08, I 2 , 56 %). Lastly, two studies [10,13] reported cardiac output at 5 and 15 minutes post-spinal anaesthesia. No statistically significant difference was seen at 5 minutes (mean difference 0.57, 95 % CI, 0.38 to 0.77, I 2 , 0 %) or 15 minutes (mean difference 0.96, 95 % CI, 0.64 to 1.28, I 2 , 18 %) post-spinal. Vasopressor requirements Five studies [10-14] reported vasopressor requirements with no difference found between the LUD and control groups (mean difference -8.82, 95% CI, -46.80 to 30.37, I 2 , 64%, figure 7. Subgroup analysis of either phenylephrine or ephedrine requirements showed no significant difference. Two studies [10,11] reported on phenylephrine requirements (mean difference -71.65, 95% CI, -268.29 to 125.00, I 2 , 90%) and three studies [12-14] reported on ephedrine requirements (mean difference 0.09, 95% CI -1.18 to 1.35, I 2 , 0%). Umbilical Artery Blood Gases and Apgar score Foetal umbilical artery blood gas values including pH, pCO 2 , pO 2 , HCO 3 , and base excess were recorded in three studies[10,11,15]. There was no statistically significant differences in the pH values (mean difference 0.01, 95% CI, -0.01 to 0.02, I 2 , 0%), pCO2 values (mean difference 0.42, 95% CI, -1.96 to 2.80, I 2 , 0%), pO2 values (mean difference -0.94, 95% CI, -2.89 to 1.01, I 2 , 58%), HCO3 values (mean difference 0.09, 95% CI, -0.27 to 0.44, I 2 , 0%), or base excess (mean difference -0.49, 95% CI, -1.55 to 0.57, I 2 , 53%). Five studies [10-12,14,15] reported the Apgar score at 5 minutes but only a single study [14] provided either the raw or analysed data for this outcome so a pooled analysis was not possible. However, none of the studies reported any difference at 5 minutes between the LUD and control group. Maternal Symptoms The incidence of maternal nausea and vomiting were recorded in 2 studies [10,12]. Pooled results showed no significant difference in the incidence of maternal nausea (odds ratio 0.50, 95% CI, 0.14 to 1.70, I 2 , 74%) or in the incidence of maternal vomiting (odds ratio 0.28, 95% CI, 0.05 to 1.54, I 2 , 0%). Main findings This systematic review and meta-analysis assessed the impact of left uterine displacement (LUD) during caesarean delivery (CD) on maternal haemodynamics and neonatal outcomes. Despite its longstanding recommendation as a preventive measure against aortocaval compression syndrome, our findings reveal limited evidence supporting the efficacy of LUD in improving maternal or neonatal outcomes under modern anaesthetic practices. Strengths and Limitations The main strength of this work is that it includes recent studies examining the benefits of LUD. Therefore, it reflects current obstetric anaesthesia practice of prophylactic blood pressure management during CD. However, there are several limitations of this meta-analysis that should be acknowledged. First, the heterogeneity among included studies, including variations in study design, sample size, and anaesthesia protocols, poses challenges for definitive conclusions. Although a random-effects model was employed, residual variability remains. Second, the relatively small number of randomized controlled trials limits the statistical power to detect subtle effects. Third, while publication bias could not be formally assessed due to the limited number of studies, it remains a general consideration in systematic reviews. However, most of the included studies reported nonsignificant findings for key outcomes, such as maternal haemodynamics and neonatal acid-base status, suggesting that any potential publication bias may not have substantially influenced our conclusions. Interpretation The pooled analysis revealed no significant differences in maternal systolic blood pressure, incidence of hypotension, or vasopressor requirements between the LUD and supine groups. These findings suggest that, in the era of routine prophylactic vasopressor use, LUD may no longer offer a substantial advantage in maintaining maternal hemodynamic stability. This observation aligns with the earlier Cochrane review, which showed that maternal position did not influence SBP, DBP or the incidence of hypotension[7]. Additionally, neonatal outcomes, including umbilical artery pH and APGAR scores, showed no significant differences. Previous studies, such as Crawford et al. (1972) and Buley et al. (1977), highlighted potential benefits of LUD on maternal and foetal outcomes during CD[4,5]. However, these studies often lacked randomization or were conducted before the widespread adoption of modern vasopressor protocols, potentially overestimating the benefits of LUD. Similarly, maternal symptoms such as nausea and vomiting were not significantly affected by the use of LUD. While nausea and vomiting are multifactorial and primarily linked to hypotension, modern anaesthesia practices with optimized vasopressor management appears to significantly mitigate these symptoms, regardless of patient positioning[16]. Our findings align with the conclusions of the Cochrane systematic review by Cluver et al. (2013, which found insufficient evidence to support specific maternal positioning during CD for preventing maternal or neonatal complications[7]. However, our review builds on these findings by including recent studies that focus on maternal vasopressor requirements and comprehensive hemodynamic parameters, providing a more nuanced understanding of LUD’s clinical implications. Clinical Implications The findings of this meta-analysis challenge the routine application of LUD during CD, especially in healthy parturients receiving prophylactic vasopressors for hypotension management. While the intervention remains low risk, its universal application may be unnecessary for most parturients undergoing elective CD with adequate hemodynamic support. An individualized approach, incorporating patient-specific risk factors such as obesity, preeclampsia, or multiple gestations, may be more appropriate. Conclusion Left uterine displacement does not significantly impact maternal haemodynamic state, vasopressor use, or neonatal outcomes in the current obstetric anaesthesia practice. Further research is needed to address the gaps identified in this review. Large-scale, multicentre randomized controlled trials should focus on standardizing LUD implementation and anaesthesia protocols to evaluate its true impact in modern clinical settings. Subgroup analyses targeting high-risk populations, such as those with severe cardiac conditions or complex obstetric histories, may elucidate scenarios where LUD could be particularly beneficial. Additionally, incorporating advanced hemodynamic monitoring, such as cardiac output and uteroplacental perfusion measurements, could provide deeper insights into the physiological effects of maternal positioning during CD. Acknowledgement We thank Mr. Chris Childs, (clinical education librarian at the Hardin Library for the health sciences) for his assistance in building the search terms for the study . Conflicts of Interest The authors declare no conflict of interest Author Contributions U.I. helped with conceptualization, methodology, investigation, data review, validation, analysis, writing original draft, writing review & editing, and visualization. M.N.B.G helped with data extraction, data review, investigation, analysis, writing original draft, writing review & editing, and visualization. R.H. helped with data extraction, data review, investigation, writing original draft, writing review & editing, and visualization. R.V.S. helped with investigation, validation, writing review & editing, and visualization Data Availability Statement Relevant data for the study are available in the supporting information References [1] Howard BK, Goodson JH, Mengert WF. Supine hypotensive syndrome in late pregnancy. Obstet Gynecol. 1953 Apr;1(4):371-7.[2] Bieniarz J, Branda LA, Maqueda E, et al. Aortocaval compression by the uterus in late pregnancy. 3. Unreliability of the sphygmomanometric method in estimating uterine artery pressure. Am J Obstet Gynecol. 1968 Dec 15;102(8):1106-15.[3] Bieniarz J, Yoshida T, Romero-Salinas G, et al. Aortocaval compression by the uterus in late human pregnancy. IV. Circulatory homeostasis by preferential perfusion of the placenta. Am J Obstet Gynecol. 1969 Jan 1;103(1):19-31.[4] Crawford JS, Burton M, Davies P. Time and lateral tilt at Caesarean section. Br J Anaesth. 1972 May;44(5):477-84.[5] Buley RJ, Downing W, Brock-Utne JG, Cuerden C. Right versus left lateral tilt for Caesarean section. Br J Anaesth. 1977 Oct;49(10):1009-15.[6] Practice Guidelines for Obstetric Anesthesia: An Updated Report by the American Society of Anesthesiologists Task Force on Obstetric Anesthesia and the Society for Obstetric Anesthesia and Perinatology. Anesthesiology. 2016 Feb;124(2):270-300.[7] Cluver C, Novikova N, Hofmeyr GJ, Hall DR. Maternal position during caesarean section for preventing maternal and neonatal complications. Cochrane Database Syst Rev. 2013 Mar 28;2013(3):CD007623.[8] Saravanan S, Kocarev M, Wilson RC, et al. Equivalent dose of ephedrine and phenylephrine in the prevention of post-spinal hypotension in Caesarean section. Br J Anaesth. 2006 Jan;96(1):95-9.[9] Calvache JA, Munoz MF, Baron FJ. Hemodynamic effects of a right lumbar-pelvic wedge during spinal anesthesia for cesarean section. Int J Obstet Anesth. 2011 Oct;20(4):307-11.[10] Lee AJ, Landau R, Mattingly JL, et al. Left Lateral Table Tilt for Elective Cesarean Delivery under Spinal Anesthesia Has No Effect on Neonatal Acid-Base Status: A Randomized Controlled Trial. Anesthesiology. 2017 Aug;127(2):241-249.[11] A. Iqbal MR, Q. Khaleel, A. Khattak. Hemodynamic Effects of Position during Spinal Anaesthesia for Elective Cesarean Section. Pakistan Journal of Medical & Health Sciences. 2019;13(3).[12] Tsai SE, Yeh PH, Hsu PK, et al. Continuous haemodynamic effects of left tilting and supine positions during Caesarean section under spinal anaesthesia with a noninvasive cardiac output monitor system. Eur J Anaesthesiol. 2019 Jan;36(1):72-75.[13] Chungsamarnyart Y, Wacharasint P, Carvalho B. Hemodynamic profiles with and without left uterine displacement: A randomized study in term pregnancies receiving subarachnoid blockade for cesarean delivery. J Clin Anesth. 2020 Apr 16;64:109796.[14] You J, Li M, Fan W, et al. Effect of different position on inferior vena cava dimensions and its influence on hemodynamics during cesarean section under combined spinal-epidural anesthesia: A randomized controlled trial. J Obstet Gynaecol Res. 2022 Dec;48(12):3103-3110.[15] Matorras R, Tacuri C, Nieto A, et al. Lack of benefits of left tilt in emergent cesarean sections: a randomized study of cardiotocography, cord acid-base status and other parameters of the mother and the fetus. J Perinat Med. 1998;26(4):284-92.[16] Habib AS. A review of the impact of phenylephrine administration on maternal hemodynamics and maternal and neonatal outcomes in women undergoing cesarean delivery under spinal anesthesia. Anesth Analg. 2012 Feb;114(2):377-90. Supplementary Material File (figures v2.docx) Download 827.66 KB File (included studies s2.docx) Download 32.58 KB Information & Authors Information Version history V1 Version 1 23 January 2026 Copyright This work is licensed under a Non Exclusive No Reuse License. Keywords delivery: caesarean section intrapartum care Authors Affiliations Unyime Ituk 0000-0003-0304-7894 [email protected] The University of Iowa Department of Anesthesia View all articles by this author Michelle Bremer Gama N University of California Davis Department of Anesthesiology and Pain Medicine View all articles by this author Rawan Hassanain The University of Iowa College of Public Health View all articles by this author Rakesh Sondekoppam V Stanford University Department of Anesthesiology Perioperative & Pain Medicine View all articles by this author Metrics & Citations Metrics Article Usage 497 views 120 downloads .FvxKWukQNSOunydq8rnd { width: 100px; } Citations Download citation Unyime Ituk, Michelle Bremer Gama N, Rawan Hassanain, et al. The Effect of Left Uterine Displacement During Caesarean Delivery on Maternal and Neonatal Outcomes: A Systematic Review & Meta-analysis. Authorea . 23 January 2026. 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