Protocol for a randomised controlled trial of fetal scalp blood lactate measurement to reduce caesarean sections during labour: the Flamingo trial [ACTRN12611000172909]

BMC Pregnancy and Childbirth

Shaun P. Brennecke¹  C. Omar Kamlin²  Mary-Ann Davey⁴  Stefan C. Kane³  Christine E. East¹ 

[1] Department of Obstetrics and Gynaecology, The University of Melbourne, Parkville 3052, Australia;Neonatal Services, Royal Women’s Hospital, Parkville 3052, Australia;Department of Perinatal Medicine, The Royal Women’s Hospital, Parkville 3052, Australia;Judith Lumley Centre (formerly Mother & Child Health Research), La Trobe University, 215 Franklin Street, Melbourne 3000, VIC, Australia

关键词: Obstetric labour complications;    Lactate;    Fetal scalp blood sampling;    Electronic fetal monitoring;    Cardiotocography;    Fetal hypoxia;    Caesarean section;   

Others  :  1232714
DOI  :  10.1186/s12884-015-0709-7

 received in 2015-01-15, accepted in 2015-10-16,  发布年份 2015

【 摘 要 】

Background

The rate of caesarean sections around the world is rising each year, reaching epidemic proportions. Although many caesarean sections are performed for concerns about fetal welfare on the basis of abnormal cardiotocography, the majority of babies are shown to be well at birth, meaning that the operation, with its inherent short and long term risks, could have been avoided without compromising the baby’s health. Previously, fetal scalp blood sampling for pH estimation was performed in the context of an abnormal cardiotocograph, to improve the identification of babies in need of expedited delivery. This test has largely been replaced by lactate measurement, although its validity is yet to be established through a randomised controlled trial. This study aims to test the hypothesis that the performance of fetal scalp blood lactate measurement for women in labour with an abnormal cardiotocograph will reduce the rate of birth by caesarean section from 38 % to 25 % (a 35 % relative reduction).

Methods/Design

Prospective unblinded randomised controlled trial conducted at a single tertiary perinatal centre. Women labouring with a singleton fetus in cephalic presentation at 37 or more weeks’ gestation with ruptured membranes and with an abnormal cardiotocograph will be eligible. Participants will be randomised to one of two groups: fetal monitoring by cardiotocography alone, or cardiotocography augmented by fetal scalp blood lactate analysis. Decisions regarding the timing and mode of delivery will be made by the treating team, in accordance with hospital protocols.

The primary study endpoint is caesarean section with secondary outcomes collected from maternal, fetal and neonatal clinical course and morbidities. A cost effectiveness analysis will also be performed. A sample size of 600 will provide 90 % power to detect the hypothesised difference in the proportion of women who give birth by caesarean section.

Discussion

This world-first trial is adequately powered to determine the impact of fetal scalp blood lactate measurement on rates of caesarean section. Preventing unnecessary caesarean sections will reduce the health and financial burdens associated with this operation, both in the index and any future pregnancies.

Trial registration

Australian New Zealand Clinical Trials Registry ACTRN12611000172909

【 授权许可】

   
2015 East et al.

【 参考文献 】

• [1]Lumbiganon P, Laopaiboon M, Gulmezoglu AM, Souza JP, Taneepanichskul S, Ruyan P, et al. Method of delivery and pregnancy outcomes in Asia: the WHO global survey on maternal and perinatal health 2007-08. Lancet. 2010;375(9713):490–9.
• [2]East CE, Leader LR, Sheehan P, Henshall NE, Colditz PB. Intrapartum fetal scalp lactate sampling for fetal assessment in the presence of a non-reassuring fetal heart rate trace. Cochrane Database Syst Rev. 2010; 3:CD006174.
• [3]Althabe F, Belizan JM. Caesarean section: the paradox. Lancet. 2006; 368(9546):1472-1473.
• [4]Li ZZR, Hilder L, Sullivan EA. Australia's mothers and babies 2011. Perinatal statistics series. Australian Institute of Health and Welfare, Canberra; 2013.
• [5]Menacker F, Hamilton BE. Recent trends in cesarean delivery in the United States. NCHS Data Brief. 2010; 35:1-8.
• [6]Macklon NS, Greer IA. The deep venous system in the puerperium: an ultrasound study. Br J Obstet Gynaecol. 1997; 104(2):198-200.
• [7]Rossen J, Okland I, Nilsen O, Eggebø T. Is there an increase of postpartum hemorrhage, and is severe hemorrhage associated with more frequent use of obstetric interventions? Acta Obstet Gynecol Scand. 2010; 89(10):1248-1255.
• [8]Jain L, Dudell GG. Respiratory transition in infants delivered by cesarean section. Semin Perinatol. 2006; 30(5):296-304.
• [9]Al-Zirqi I, Stray-Pedersen B, Forsen L, Vangen S. Uterine rupture after previous caesarean section. BJOG. 2010; 117(7):809-820.
• [10]Getahun D, Oyelese Y, Salihu HM, Ananth CV. Previous cesarean delivery and risks of placenta previa and placental abruption. Obstet Gynecol. 2006; 107(4):771-778.
• [11]Smith GC, Pell JP, Dobbie R. Caesarean section and risk of unexplained stillbirth in subsequent pregnancy. Lancet. 2003; 362(9398):1779-1784.
• [12]East CE. Fetal intrapartum pulse oximetry. St. Lucia, Qld; The University of Queensland (Thesis). 2006.
• [13]The American College of Obstetricians and Gynecologists. ACOG Practice Bulletin No. 106: Intrapartum fetal heart rate monitoring: nomenclature, interpretation, and general management principles. Obstet Gynecol. 2009;114(1):192-202.
• [14]Intrapartum Care: Care of healthy women and their babies during childbirth. National Institute for Health and Care Excellence: Guidance. RCOG Press, London; 2014.
• [15]Liston R, Sawchuck D, Young D. Fetal health surveillance: antepartum and intrapartum consensus guideline. J Obstet Gynaecol Canada. 2007; 29(9 Suppl 4):S3-56.
• [16]Intrapartum fetal surveillance : clinical guidelines. 3rd ed. RANZCOG, Melbourne; 2014.
• [17]The American College of Obstetricians and Gynecologists. ACOG Committee Opinion. Number 326, December 2005. Inappropriate use of the terms fetal distress and birth asphyxia. Obstet Gynecol. 2005;106(6):1469-1470.
• [18]Umstad MP. The predictive value of abnormal fetal heart rate patterns in early labour. Aust N Z J Obstet Gynaecol. 1993; 33(2):145-149.
• [19]Devane D, Lalor J. Midwives' visual interpretation of intrapartum cardiotocographs: intra- and inter-observer agreement. J Adv Nurs. 2005; 52(2):133-141.
• [20]Palomaki O, Luukkaala T, Luoto R, Tuimala R. Intrapartum cardiotocography -- the dilemma of interpretational variation. J Perinat Med. 2006; 34(4):298-302.
• [21]Saling E, Schneider D. Biochemical supervision of the foetus during labour. J Obstet Gynaecol Br Commonw. 1967; 74(6):799-811.
• [22]Jaiyesimi RK, Hickey WP. Fetal haemorrhage after fetal scalp blood sampling. Lancet. 1990; 336(8718):819-820.
• [23]Maiques V, Garcia-Tejedor A, Perales A, Navarro C. Intrapartum fetal invasive procedures and perinatal transmission of HIV. Eur J Obstet Gynecol Reprod Biol. 1999; 87(1):63-67.
• [24]Pachydakis A, Belgaumkar P, Sharmah A. Persistent scalp bleeding due to fetal coagulopathy following fetal blood sampling. Int J Gynecol Obstet. 2006; 92(1):69-70.
• [25]Kruger K, Hallberg B, Blennow M, Kublickas M, Westgren M. Predictive value of fetal scalp blood lactate concentration and pH as markers of neurologic disability. Am J Obstet Gynecol. 1999; 181(5):1072-1078.
• [26]Westgren M, Kublickas M, Kruger K. Role of lactate measurements during labor. Obstet Gynecol Surv. 1999; 54(1):43-48.
• [27]Alfirevic Z, Devane D, Gyte GML. Continuous cardiotocography (CTG) as a form of electronic fetal monitoring (EFM) for fetal assessment during labour. Cochrane Database Syst Rev. 2013; 5: Article ID CD006066
• [28]Haverkamp AD, Orleans M, Langendoerfer S, McFee J, Murphy J, Thompson HE. A controlled trial of the differential effects of intrapartum fetal monitoring. Am J Obstet Gynecol. 1979; 134(4):399-412.
• [29]Goodwin TM, Milner-Masterson L, Paul RH. Elimination of fetal scalp blood sampling on a large clinical service. Obstet Gynecol. 1994; 83(6):971-974.
• [30]Kruger K, Kublickas M, Westgren M. Lactate in scalp and cord blood from fetuses with ominous fetal heart rate patterns. Obstet Gynecol. 1998; 92(6):918-922.
• [31]Ramanah R, Martin A, Riethmuller D, Maillet R, Schaal JP. Value of fetal scalp lactate sampling during labour: a comparative study with scalp pH. Gynecol Obstet Fertil. 2005; 33(3):107-112.
• [32]Allen RM, Bowling FG, Oats JJN. Determining the fetal scalp lactate level that indicates the need for intervention in labour. Aust N Z J Obstet Gynaecol. 2004; 44(6):549-552.
• [33]Engidawork E, Chen Y, Dell'Anna E, Goiny M, Lubec G, Ungerstedt U, et al. Effect of perinatal asphyxia on systemic and intracerebral pH and glycolysis metabolism in the rat. Exp Neurol. 1997;145(2 Pt 1):390–6.
• [34]Myers R, Wagner K, De Courten G. Lactic acid accumulation in tissue as cause of brain injury and death in cardiogenic shock from asphyxia. Clinical perinatal biochemical monitoring, Williams & Wilkins, Baltimore; 1981.
• [35]Nordström L, Chua S, Roy A, Arulkumaran S. Quality assessment of two lactate test strip methods suitable for obstetric use. J Perinat Med. 1998; 26(2):83-88.
• [36]Orsonneau J-L, Fraissinet F, Sebille-Rivain V, Dudouet D, Bigot-Corbel E. Suitability of POC lactate methods for fetal and perinatal lactate testing: considerations for accuracy, specificity and decision making criteria. Clin Chem Lab Med. 2013; 2:397.
• [37]Reif P, Lakovschek I, Tappauf C, Haas J, Lang U, Schöll W. Validation of a point-of-care (POC) lactate testing device for fetal scalp blood sampling during labor: clinical considerations, practicalities and realities. Clin Chem Lab Med. 2014; 52(6):825-833.
• [38]Wiberg-Itzel E, Lipponer C, Norman M, Herbst A, Prebensen D, Hansson A, et al. Determination of pH or lactate in fetal scalp blood in management of intrapartum fetal distress: randomised controlled multicentre trial. BMJ (Clinical research ed). 2008;336(7656):1284–7.
• [39]The Royal Women's Hospital. Policy, Guideline and Procedure Manual: Fetal Blood Sampling. In: Melbourne, Victoria, Australia; The Royal Women's Hospital. 2014.
• [40]Nordstrom L, Ingemarsson I, Kublickas M, Persson B, Shimojo N, Westgren M. Scalp blood lactate: a new test strip method for monitoring fetal wellbeing in labour. Br J Obstet Gynaecol. 1995; 102(11):894-899.
• [41]Nordstrom L, Ingemarsson I, Persson B, Shimojo N, Westgren M. Lactate in fetal scalp blood and umbilical artery blood measured during normal labor with a test strip method. Acta Obstet Gynecol Scand. 1994; 73(3):250-254.
• [42]Nordstrom L, Achanna S, Naka K, Arulkumaran S. Fetal and maternal lactate increase during active second stage of labour. BJOG. 2001; 108(3):263-268.
• [43]Milley JR. Uptake of exogenous substrates during hypoxia in fetal lambs. Am J Physiol. 1988; 254(5 Pt 1):e572-578.
• [44]Westgren M. Lactate compared with pH analysis at fetal scalp blood sampling: a prospective randomised study. Br J Obstet Gynaecol. 1998; 105(1):29.
• [45]Vandenbussche F. Effectiveness of fetal scalp blood sampling for the prevention of cesarean section in case of suspected fetal distress during labor (SCALP-trial): A randomized controlled multicenter study. In: Netherlands trial register. 2013. http://www. trialregister.nl/trialreg/admin/rctview.asp?TC=3837 webcite
• [46]Chandraharan E. Fetal scalp blood sampling during labour: is it a useful diagnostic test or a historical test that no longer has a place in modern clinical obstetrics? BJOG. 2014; 121(9):1056-1060.
• [47]Jorgensen JS, Weber T. Fetal scalp blood sampling in labor--a review. Acta Obstet Gynecol Scand. 2014; 93(6):548-555.
• [48]Schulz KF, Altman DG, Moher D. CONSORT 2010 statement: updated guidelines for reporting parallel group randomised trials. BMJ (Clinical research ed). 2010; 340:c332.
• [49]East CE, Brennecke SP, Chan FY, King JF, Beller EM, Colditz PB. Clinicians’ evaluations of fetal oximetry sensor placement in a multicentre randomised trial (the FOREMOST trial). Aust N Z J Obstet Gynaecol. 2006; 46(3):234-239.
• [50]East CE, Brennecke SP, King JF, Chan FY, Colditz PB. The effect of intrapartum fetal pulse oximetry, in the presence of a nonreassuring fetal heart rate pattern, on operative delivery rates: A multicenter, randomized, controlled trial (the FOREMOST trial). Am J Obstet Gynecol. 2006; 194(3):606.e601-606.e616.
• [51]East CE, Chan FY, Brennecke SP, King JF, Colditz PB. Women's Evaluations of Their Experience in a Multicenter Randomized Controlled Trial of Intrapartum Fetal Pulse Oximetry (The FOREMOST Trial). Birth. 2006; 2:101.
• [52]East CE, Gascoigne MB, Doran CM, Brennecke SP, King JF, Colditz PB. A cost-effectiveness analysis of the intrapartum fetal pulse oximetry multicentre randomised controlled trial (the FOREMOST trial). BJOG. 2006; 113(9):1080-1087.
• [53]National Health and Medical Research Council (Australia). Changes to National statement on ethical conduct in human research, 2007. Canberra: NHMRC-publications. 2014.
• [54]Drummond MF. Methods for the economic evaluation of health care programmes/Michael F. Drummond … [et al.]. 3rd ed. Oxford: Oxford University Press; 2005.
• [55]Macones GA, Goldie SJ, Peipert JF. Cost-Effectiveness Analysis: An Introductory Guide for Clinicians. Obstet Gynecol Surv. 1999; 54(10):663-672.
• [56]Donoghue D, Cust A. Australian and New Zealand Neonatal Network, 1998. AIHW National Perinatal Statistics Unit, Sydney; 2000.
• [57]Hannah MEMM, Hannah WJMD, Hellmann JMBB, Hewson SBA, Milner RMIS, Willan AP. Induction of Labor as Compared with Serial Antenatal Monitoring in Post-Term Pregnancy: A Randomized Controlled Trial. N Engl J Med. 1992; 326(24):1587-1592.
• [58]Sarnat HB, Sarnat MS. Neonatal encephalopathy following fetal distress. A clinical and electroencephalographic study. Arch Neurol. 1976; 33(10):696-705.
• [59]East CE. Fetal pulse oximetry for fetal assessment in labour. Cochrane Database Syst Rev. 2014;10.
• [60]Allen VM, O'Connell CM, Farrell SA, Baskett TF. Economic implications of method of delivery. Am J Obstet Gynecol. 2005; 193(1):192-197.
• [61]Gallego G. New rules for caesarean section. In: Health Policy Monitor. 2008. http://hpm. org/en/Surveys/CHERE_-_Australia/11/New_rules_for_caesarean_section.html webcite