200811 obstetrics 1

OBSTETRICS

Blood Transfusion for Primary PostpartumHemorrhage: A Tertiary Care Hospital ReviewMrinalini Balki, MBBS, MD,1 Sudhir Dhumne, MBBS, MD,1 Shilpa Kasodekar, MBBS, MD,1

Gareth Seaward, MBBCh, FRCSC, MSc, Jose C.A. Carvalho, MD, PhD, FANZCA, FRCPC1,2

1Department of Anesthesia and Pain Management, Mount Sinai Hospital, University of Toronto, Toronto ON2Department of Obstetrics and Gynaecology, Mount Sinai Hospital, University of Toronto, Toronto ON

Abstract

Objective: To describe the common characteristics, clinicalmanagement, and outcome of patients requiring blood transfusionwithin 24 hours of delivery.

Methods: We conducted a retrospective cohort study of patients whoreceived blood transfusion for postpartum hemorrhage (PPH) inthe first 24 hours post-delivery, over a five-year period(2000–2005). The medical records of patients were reviewed toobtain information about demographics, pregnancy and deliverycharacteristics, transfusion data, and complications.

Results: The overall blood transfusion rate for PPH was 0.31%(104/33 631 deliveries). The rate of blood transfusion in womenwho had a Caesarean section during labour was 0.49%, whereasin women who had a vaginal delivery or elective Caesareansection it was 0.28% and 0.23%, respectively. Antenatal riskfactors for PPH were identified in 61% of patients, and 39% ofpatients developed intrapartum risk factors. The most importantetiological factors were uterine atony (38.5%) and retainedproducts of conception (33.7%). Twenty-one percent of thepatients developed coagulopathy, and 24% required admission tothe intensive care unit.

Conclusion: Severe primary PPH requiring blood transfusion can bepredicted in the majority of patients on the basis of antenatal riskfactors, while the remaining patients require vigilant monitoring forrisk factors during labour and delivery. In the multidisciplinaryeffort to prevent and control major PPH, we should re-evaluate thepharmacotherapy for PPH and ensure careful removal of retainedplacental tissue after delivery.

Résumé

Objectif : Décrire les caractéristiques, la prise en charge clinique etles issues courantes en ce qui concerne les patientes nécessitantune transfusion sanguine dans les 24 heures suivantl’accouchement.

Méthodes : Nous avons mené, sur une période de cinq ans(2000–2005), une étude de cohorte rétrospective portant sur despatientes qui avaient reçu une transfusion sanguine motivée parune hémorragie postpartum (HPP) au cours des 24 premièresheures suivant l’accouchement. Les dossiers médicaux des

patientes ont été analysés afin d’en tirer des renseignementsquant aux caractéristiques démographiques, aux caractéristiquesde la grossesse et de l’accouchement, aux données sur latransfusion et aux complications.

Résultats : Le taux global de transfusion sanguine motivée parl’HPP était de 0,31 % (104/33 631 accouchements). Le taux detransfusion sanguine chez les femmes qui avaient subi unecésarienne au cours du travail était de 0,49 %, tandis que chez lesfemmes qui avaient connu un accouchement vaginal ou unecésarienne de convenance, il était de 0,28 % et de 0,23 %,respectivement. Des facteurs de risque prénatals en ce quiconcerne l’HPP ont été identifiés chez 61 % des patientes; 39 %des patientes en sont venues à présenter des facteurs de risqueintrapartum. Les facteurs étiologiques les plus importants étaientl’atonie utérine (38,5 %) et la rétention de produits de conception(33,7 %). Vingt et un pour cent des patientes en sont venues àprésenter une coagulopathie; 24 % des patientes ont nécessitéune admission à l’unité des soins intensifs.

Conclusion : Chez la plupart des patientes, l’HPP primaire gravenécessitant une transfusion sanguine peut être prédite en fonctionde leurs facteurs de risque prénatals, tandis que chez les autrespatientes, une surveillance vigilante des facteurs de risque aucours du travail et de l’accouchement s’avère nécessaire. Dans lecadre des efforts multidisciplinaires pour la prévention et lamaîtrise de l’HPP majeure, nous devrions réévaluer lapharmacothérapie visant l’HPP et nous assurer du retrait intégraldes tissus placentaires à la suite de l’accouchement.

J Obstet Gynaecol Can 2008;30(11):1002–1007

INTRODUCTION

Primary postpartum hemorrhage is a major cause ofmaternal morbidity and mortality worldwide, and cer-

tainly remains an important cause of “near miss” severemorbidity in Canada.1,2 This major public health issue hasbeen further aggravated by a recent unexplained increase inthe frequency and severity of PPH in Canada.2 It has there-fore been suggested that a review of severe maternal mor-bidity, which most commonly results from major PPHrequiring blood transfusion, may provide a better appraisalof the threats to maternal health in pregnancy.

The interdisciplinary management of PPH involves resusci-tation using fluid replacement, administration of uterotonic

1002 � NOVEMBER JOGC NOVEMBRE 2008

OBSTETRICS

Key Words: Postpartum hemorrhage, blood transfusion, riskfactors, vaginal delivery, Caesarean section

Competing Interests: None declared.

Received on January 28, 2008

Accepted on April 3, 2008

drugs, a variety of surgical techniques to control bleeding,and, if blood loss becomes excessive, blood transfusion.The recent introduction of interventional radiologic tech-niques for selective uterine artery embolization has beenrevolutionary in reducing blood loss during delivery inwomen with a prior diagnosis of abnormal placentation3;however, most PPH is due to uterine atony, and therefore isnot directly amenable to control using embolization meth-ods. Being prepared for blood transfusion remains a veryimportant aspect of the management in women with thissevere complication.

Many studies have analyzed the risk factors associated withPPH in women undergoing vaginal delivery and Caesareansection, but no study has examined the subset of patientsrequiring blood transfusion.4–6 The present study wasdesigned to identify the population at risk of major PPHrequiring blood transfusion at our institution, and to evalu-ate the clinical management and outcome of these patients.

METHODS

We conducted a retrospective cohort study of all obstetricpatients who reached at least 24 weeks of gestation andreceived blood transfusion within 24 hours of delivery,between June 1, 2000 and June 30, 2005. This period waschosen because interventional radiologic techniques, whichcomplement the practice of modern obstetrics, were intro-duced into clinical practice during this time. The patientswith postpartum blood transfusion were identified througha computerized search of the hospital database, and theirmedical records were verified against the eligibility criteria.Their charts were reviewed to assess (1) the risk factors forPPH, (2) the pharmacological, surgical and interventionalradiology management undertaken, (3) the transfusion data,and (4) the patient outcome.

PPH was identified if there was a blood loss in excess of500 mL after a vaginal delivery, 1000 mL after CS, or a 10%change in hematocrit. Other factors identifying PPHincluded the need for blood transfusion, or any amount ofblood loss that threatened the woman’s hemodynamic sta-bility.7 The risk factors for PPH, as described in previousstudies, included the factors that could be identifiedantenatally and those presenting intrapartum.4–6

Antepartum factors included multiple gestation, abnormalplacentation, bleeding or coagulation disorders,macrosomia, pregnancy-induced hypertension, chorio-

amnionitis, previous uterine surgery, or a history of PPH.Intrapartum factors consisted of a prolonged first stageof labour (latent labour > 20 hours in null ipara or> 1 4 hour s in mu l t i pa r a ; c e rv i c a l d i l a t a t i on of< 1 .2 cm/hour in nullipara or < 1.5 cm/hour inmultipara), a prolonged second stage of labour (> 2 hours innullipara without epidural anaesthesia or > 3 hours innullipara with epidural anaesthesia; > 1 hour in multiparawithout epidural anaesthesia or > 2 hours in multipara withepidural anaesthesia), or a prolonged third stage of labour(� 30 minutes). Additional risk factors included labours thatwere induced or augmented with oxytocin.4,5

At our institution, the pharmacological and surgical man-agement of PPH is primarily based on the guidelines set bythe MoreOB program of the Society of Obstetricians andGynaecologists of Canada,8 and the perioperative transfu-sion of blood products follows the Health Canada guide-lines.9 The transfusion data, in the form of transfusion ofpacked red blood cells, fresh frozen plasma, platelets,cryoprecipitate or recombinant factor VII, were reviewed inall cases. We recorded patient outcomes in the form ofimmediate and delayed morbidity and mortality as a resultof major PPH and blood transfusion.

Ethics approval for this study was obtained from theResearch Ethics Board at Mount Sinai Hospital.

RESULTS

During the study period, 33 631 patients delivered at ourinstitution. Of these, 23 478 patients (70%) delivered vagi-nally, 5073 (15%) delivered by CS during labour, and 5080(15%) delivered by elective CS before labour. The overallincidence of primary PPH was 3.2% (1078/33 631). Bloodtransfusion within 24 hours of delivery was required in0.31% of the patients (104/ 33 631). The blood transfusionrate was highest in the patients requiring CS during labour(0.49%, or 25/5073), compared with 0.28% (67/23478) inthose who delivered vaginally, and 0.23% (12/5080) inthose who had elective CS before labour. In patients whoexperienced labour, blood transfusion was more commonlyrequired in those with spontaneous labour (48%) than inthose with induced (26%) or augmented labour (26%).Normal placentation was present in the majority of patients(83%). Sixty-seven percent of patients with abnormalplacentation were delivered by CS. The principal causes ofPPH were uterine atony (38.5%) and retained products ofconception (33.7%) (Table 1). The risk factors for PPHcould be identified antenatally in 61% of patients, and areshown in Table 2. The remaining 39% of patients receivingblood transfusions had one or more intrapartum riskfactors for PPH.

Blood Transfusion for Primary Postpartum Hemorrhage: A Tertiary Care Hospital Review

NOVEMBER JOGC NOVEMBRE 2008 � 1003

ABBREVIATIONS

CS Caesarean section

PPH postpartum hemorrhage

PRBC packed red blood cell

The mean lowest hemoglobin concentration during bleed-ing was 63 � 15 g/L, the mean lowest hematocrit was 0.19 �

0.44%, and the mean lowest platelet count was 128 000 �

74 000/mm3 (Table 3). All patients received transfusions ofPRBCs (median 3 units; 900 mL). Recombinant factor VIIwas administered in one patient. The use of other bloodproducts is shown in Table 4. Details of the uterotonicagents used are shown in Table 5. All four uterotonic agents(oxytocin, ergometrine, carboprost, and misoprostol) wereadministered concomitantly in only 20% of the cases, whileabout 50% of the patients received an additional drug otherthan oxytocin. Dilatation and curettage (26.9%) and manualremoval of the placenta (17.3%) were the most commonsurgical procedures performed, and hysterectomy and gelfoam embolization of uterine arteries were each performedin 16.3% of patients (Table 5).

Invasive monitoring with arterial line and central veincannulation was carried out in 37.5% and 14.4% of patients,respectively, and both of these procedures were used in

12.5% of patients. Twenty percent of patients developedcoagulopathy including disseminated intravascular coagula-tion, and 24% required admission to the intensive care unit.Pulmonary complications were observed in 2.8% ofpatients, and cardiac complications were observed in 1%.No deaths occurred in this series.

DISCUSSION

Despite improvements in management strategies, PPHremains one of the leading causes of maternal morbidityand mortality worldwide.1 The United Kingdom Confiden-tial Enquiry into Maternal Deaths in 2000–2002 reported17 deaths due to hemorrhage, compared with seven in theprevious triennium; 10 were due to PPH, compared withone in the previous report.10 A recent population-basedprospective study in Scotland and a study in Nova Scotiareported hemorrhage to be the most important cause ofmajor obstetric morbidity, accounting for more than 50%of the overall incidence.11,12

OBSTETRICS


Table 1. Demographics, obstetric details, and etiology of postpartum hemorrhage requiring bloodtransfusion

Total(n = 104)

Vaginal deliveries(n = 67)

Elective CS(n = 12)

CS during labour(n = 25)

Demographics

Age in years, ± SD 33.6 � 4.8 33.3 � 4.9 35.0 � 5.0 33.7 � 4.8

Weight in kg, ± SD 75.9 � 13.3 75.4 � 13.7 78.9 � 15.7 75.6 � 8.6

Gestational age in weeks ± SD 35.8 � 6.1 35.0 � 7.0 37.3 � 2.2 36.9 � 4.7

Primipara, n (%) 56 (53.8) 38 (56.7) 3 (25) 15 (60)

Multipara, n (%) 48 (46.2) 29 (43.3) 9 (75) 10 (40)

Labour (n = 92), n (%)

Spontaneous 44 (47.8) 33 (49.2) – 11 (44)

Induced 24 (26.1) 16 (23.9) – 8 (32)

Augmented 24 (26.1) 18 (26.9) – 6 (24)

Prolonged first stage 12 (13) 0 – 12 (52)

Prolonged second stage 6 (6.5) 4 (6.0) – 2 (8)

Prolonged third stage 1 (1.1) 1(1.5) – 0

Placentation, n (%)

Normal 86 (82.6) 61 (91) 6 (50) 19 (76)

Previa 7 (6.7) 2 (3) 2 (16.7) 3 (12)

Accreta 7 (6.7) 4 (6) 1 (8.3) 2 (8)

Percreta 3 (2.9) 0 3 (25) 0

Abruption 1 (0.9) 0 0 1 (4)

Etiology of PPH, n (%)

Atony 40 (38.5) 18 (26.9) 5 (41.7) 17 (68)

Retained tissues 35 (33.7) 28 (41.8) 5 (41.7) 2 (8)

Genital tract trauma 13 (12.5) 12 (17.9) 1 (8.3) 0

Coagulopathy 7 (6.7) 4 (6.0) 0 3 (12)

Undetermined 9 (8.7) 5 (7.5) 1 (8.3) 3 (12)

In our study, the patients requiring blood transfusion repre-sented only 10% of the total patients with PPH. The inci-dence of transfusion for primary PPH (occurring within 24hours of delivery) was 0.31%. This result is consistent withthe data of Reyal et al., which showed a frequency of trans-fusion of 0.23% during the period 1992–1998.13 The ratesof blood transfusion vary in different institutions becauseof a great variance in physicians’ attitudes toward bloodtransfusions. Ransom et al. reported a frequency of transfu-sion of 0.47% in patients undergoing vaginal deliveries, butRouse et al. found a rate of 3.2% in patients having a pri-mary CS and 2.2% in those having a repeat CS.14,15 Thishigh incidence of transfusion could perhaps be due to lackof standardized transfusion strategies in the authors’ institu-tion. Various national health care organizations have intro-duced new policy guidelines for PRBC transfusions,16–18 asa result of which there has been an overall decline in thenumber of PRBC transfusions in the current decade.19

Despite this low rate of transfusion in our patient popula-tion, morbidity in the form of DIC, cardiac and pulmonarycomplications, and a need for ICU admission was seen inabout 32% of patients requiring blood transfusion. Themarkers for this major maternal morbidity were the transfu-sion of more than five units of PRBCs, emergency hysterec-tomy, and/or uterine artery embolization.

The results of our study prompted us to review the currentprotocols for the pharmacologic and surgical managementof PPH in order to minimize the risk for potential bloodtransfusions. The prophylactic administration of oxytocinafter delivery is the current standard for prevention of PPH,because of its rapid onset of action and the lack of seriousadverse effects if administered appropriately.20 Neverthe-less, in clinical practice this drug is often administered inexcessive amounts, especially in the event of postpartumbleeding, which can lead to several undesirablehemodynamic effects such as hypotension and circulatory

collapse.21–23 On the other hand, other uterotonic drugs arestill underused despite ready availability in most centres. Inthe current study, all four uterotonic agents available at ourinstitution (oxytocin, ergometrine, carboprost, andmisoprostol) were concomitantly administered in only 20%of the cases, while only about 50% of the patients receivedan additional drug other than oxytocin.

Interestingly, we found a twofold increase in the require-ment for blood transfusion (0.49%) in patients undergoingCS during labour compared with those undergoing electiveCS (0.23%). These results are concurrent with our previousfindings that labouring patients undergoing CS had approx-imately twice the amount of blood loss experienced bynon-labouring patients undergoing CS.24,25 In accordancewith the literature, this can be attributed to the inappropri-ate myometrial response to oxytocin arising fromoxytocin-receptor desensitization due to prolongedoxytocin exposure during labour.26,27 This effect is likely tobe exaggerated in patients with induced or augmentedlabours, and, although not significantly observed in ourstudy population, one would predict a higher incidence ofhemorrhage in this subset of patients, on the basis of clinicaltrials and biomolecular studies on oxytocin-receptor desen-sitization.24,27 Thus, the labouring uterus is likely to be lessresponsive to the administration of further oxytocin afterdelivery; hence, in the event of postpartum bleeding, thetimely use of additional uterotonics that act via pathwaysother than oxytocin receptors is certainly desirable.

Although uterine atony was the most common etiology inour patients, retained products of conception alsoaccounted for a large number of patients with postpartumbleeding requiring blood transfusion. The higher incidenceof retained placenta in elective CS patients (42%) can beattributed to abnormal placentation or previous uterine sur-gery in these patients. In a study of 154 311 deliveries,Sheiner et al. found retained placenta to be the most signifi-cant risk factor for PPH (OR 3.5; 95% CI 2.1–5.8).28 Someaspects of the obstetrical techniques used warrant reassess-ment in light of this finding. These include the careful man-agement of the third stage of labour in vaginal deliveries todecrease the incidence of retained placental tissue, andallowing spontaneous placental delivery during CS. Theapproach of waiting for the uterine fundus to contract at CSand allowing the spontaneous expulsion of the placenta,rather than removing it manually, has been shown todecrease total blood loss.29 Recently, the injection ofuterotonic agents into the umbilical vein has shown to be anon-invasive, effective, and clinically safe method ofreducing the rate of placentas remaining undeliveredbeyond 15 minutes, and of minimizing the subsequentblood loss.30,31 Inspection of the placenta for completeness



Table 2. Antenatal risk factors for postpartumhemorrhage requiring blood transfusion

Risk factors n (%)

Previous uterine surgery 22 (21.2)

Antepartum hemorrhage 21 (20.1)

Multiple gestation 18 (17.3)

Macrosomia 17 (16.3)

Abnormal placentation 17 (16.3)

Pregnancy induced hypertension 14 (13.5)

Chorioamnionitis 9 (8.7)

Blood disorders/anticoagulation 8 (7.7)

History of PPH 5 (4.8)

and early detection of retained tissue by the use of ultra-sound may help to reduce the incidence of retainedproducts of conception after delivery.

The application of uterine compression sutures, such asB-Lynch sutures or their modifications, is a simple, conser-vative procedure to stop hemorrhage and has been shownto obviate the need for hysterectomy.32,33 However, in ourstudy, these sutures were applied in only 3% of the patientsreceiving blood transfusions. Hysterectomy is the last resortin the management of PPH unresponsive to oxytocic drugsor other conservative methods.7 Uterine arteryembolization is an alternative to hysterectomy in institu-tions where interventional radiology services are readily

accessible, and its high incidence of use in our patientpopulation indicates its efficacy.

Our study was not intended to identify risk factors for PPH,since these have already been described; rather, we com-piled common characteristics seen in patients with majorbleeding episodes requiring blood transfusions. The currentstudy was also limited by the retrospective data collectionand a lack of case-control design; however, it gives us a pro-file of the patients requiring blood transfusions postpartum,and it provides details of the pharmacological management,transfusion requirements and patient outcomes in thesepatients, which have not been described previously.

OBSTETRICS


Table 5. Pharmacological and surgical management of postpartum hemorrhage

Number of patients (%) Mean dose � SD

Drugs

Oxytocin (IU) 104 (100) 47 � 19

Ergometrine (�g) 59 (57) 450 � 260

Carboprost (�g) 51 (49) 730 � 421

Misoprostol (�g) 25 (24) 976 � 167

Surgical Procedures

Dilatation and curettage 28 (26.9)

Manual removal of placenta 18 (17.3)

Hysterectomy 17 (16.3)

Uterine artery embolization 17 (16.3)

Repair of lacerations 14 (13.5)

Uterine artery ligation 6 (5.8)

Uterine compression suture 3 (2.9)

Table 4. Transfusion data

Blood products Number of patients (%) Median units (range)

Packed red blood cells 104 (100) 3 (1–26)

Fresh frozen plasma 44 (42.3) 4 (1–22)

Platelets 19 (18.2) 5 (1–20)

Cryoprecipitate 10 (9.6) 5.5 (1–15)

Recombinant Factor VII 1 (1) 1

Table 3. Blood work during postpartum hemorrhage

Parameter Baseline Lowest Post-transfusion

Hemoglobin, g/L 117 � 15 63 � 15 91 � 15

Hematocrit, % 0.35 � 0.42 0.19 � 0.44 0.27 � 0.44

Platelets, 000/mm3216 � 84 128 � 74 170 � 81

INR 1.0 � 0.1 1.4 � 0.9 1.1 � 0.1

Values expressed as mean � SD

CONCLUSION

The incidence of postpartum blood transfusion for primaryPPH at our institution is low, and the majority of high-riskpatients can be identified with careful antenatal examina-tion. However, many patients develop risk factors for PPHduring labour, and those developing severe complicationspostpartum are often difficult to identify before delivery.Hence, vigilant monitoring of patients to identify risk fac-tors for bleeding during the peripartum period is necessaryfor more effective planning of resources and better clinicalmanagement. An aggressive prophylactic pharmacologicalapproach and early recognition of retained products of con-ception are vital to reduce the incidence of blood transfu-sions and to prevent life-threatening complications. Weencourage other practitioners to review their own practicesin regard to the management of PPH and bloodtransfusion.

ACKNOWLEDGEMENTS

This paper was presented as a poster at the Society forObstetric Anesthesia and Perinatology Meeting, Holly-wood, Florida, USA, April 26–30, 2006.

The authors acknowledge Kristi Downey (Research Assis-tant) for organizing the database and Dr John Kingdom(Professor of Obstetrics and Gynaecology, University ofToronto) for reviewing the manuscript.

REFERENCES

1. World Health Organization. Attending to 136 million births, every year: makeevery mother and child count: The World Report 2005. Geneva, Switzerland:WHO, 2005. p. 61–73.

2. Joseph KS, Rouleau J, Kramer MS, Young DC, Liston RM, Baskett TF. Maternalhealth study group of the Canadian Perinatal Surveillance System. Investigationof an increase in postpartum hemorrhage in Canada. BJOG 2007;114:751–9.

3. Kachura JR. The role of interventional radiology in obstetrics. Fetal andMaternal Medicine Review 2004; 15:145–180.

4. Combs CA, Murphy EL, Laros RK. Factors associated with postpartumhemorrhage with vaginal birth. Obstet Gynecol 1991;77:69–76.

5. Combs CA, Murphy EL, Laros RK. Factors associated with hemorrhage incesarean deliveries. Obstet Gynecol 1991;77:77–82.

6. Magann EF, Evans S, Hutchinson M, Collins R, Howard BC, Morrison JC.Postpartum hemorrhage after vaginal birth: an analysis of risk factors. SouthMed J 2005;98:419–22.

7. Schuurmans N, MacKinnon C, Lane C, Etches D. Prevention and managementof postpartum hemorrhage. J Soc Obstet Gynaecol Can 2000;22:271–81.

8. MOREOB Program Website. Available at: http://www.moreob.com. AccessedAugust 12, 2008.

9. Callum JL, Pinkerton PH. Bloody easy. Blood transfusions, blood alternativesand transfusion Reactions. 2nd Ed. Toronto: The Sunnybrook and Women’sCollege Health Sciences Centre; 2003.

10. Confidential Enquiry into Maternal and Child Health. Why Mothers Die2000–2002. Available at: http://www.cemach.org.uk. Accessed August 12, 2008.

11. Brace V, Penney G, Hall M. Quantifying severe maternal morbidity: a Scottishpopulation study. BJOG 2004;111:481–4.

12. Baskett TF, O’Connell CM. Severe obstetric maternal morbidity: a 15-yearpopulation-based study. J Obstet Gynaecol 2005;25(1):7–9.

13. Reyal F, Sibony O, Oury JF, Luton D, Bang J, Blot P. Criteria for transfusion insevere postpartum hemorrhage: analysis of practice and risk factors. Eur JObstet Gynecol Reprod Biol 2004;112:61–4.

14. Ransom SB, Fundaro G, Dombrowski MP. The cost-effectiveness of routinetype and screen admission testing for expected vaginal delivery. Obstet Gynecol1998;92:493–5.

15. Rouse DJ, MacPherson C, Landon M, Varner MW, Leveno KJ, Moawad AH,et al. Blood transfusion and cesarean delivery. Obstet Gynecol 2006;108:891–7.

16. Expert Working Group. Guidelines for red blood cell and plasma transfusion foradults and children. CMAJ 1997;156:S1–25.

17. Practice guidelines for blood component therapy: a report by the AmericanSociety of Anesthesiologists Task Force on Blood Component Therapy.Anesthesiology 1996;84:732–47.

18. British Committee for Standards in Haematology. Guidelines for the clinical useof red cell transfusions. Br J Haematol 2001;113:24–31.

19. Eogan M, O’Connell MP, Collins R, Murphy K, Keane DP. Trends in bloodtransfusion in obstetrics at the National Maternity Hospital 1991–2001. Ir Med J2003;96:247–8.

20. Cotter A, Ness A, Tolossa J. Prophylactic oxytocin for the third stage of labour.Cochrane Database Syst Rev 2001;4:CD001808.

21. Pinder AJ, Dresner M, Calow C, Shorten GD, O’Riordan J, Johnson R.Haemodynamic changes caused by oxytocin during Cesarean section underspinal anesthesia. Int J Obstet Anesth 2002;11:156–9.

22. Weis FR Jr, Markello R, Mo B, Bochiechio P. Cardiovascular effects of oxytocin.Obstet Gynecol 1975;46:211–4.

23. Why Mothers Die 1997–1999, the fifth report of the confidential enquiries intomaternal deaths in the United Kingdom. London (UK):RCOG Press;2001:134–49.

24. Balki M, Ronayne M, Davies S, Fallah S, Kingdom J, Windrim R, et al. Minimumoxytocin dose requirement after cesarean delivery for labor arrest. ObstetGynecol 2006;107:45–50.

25. Carvalho JC, Balki M, Kingdom J, Windrim R. Oxytocin requirements at electivecesarean delivery: a dose-finding study. Obstet Gynecol 2004;104:1005–10.

26. Robinson CR, Schumann R, Zhang P, Young RC. Oxytocin-induceddesensitization of the oxytocin receptor. Am J Obstet Gynecol2003;188:497–502.

27. Phaneuf S, Rodriguez Linares B, TambyRaja RL, MacKenzie IZ, Lopez Bernal A.Loss of myometrial oxytocin receptors during oxytocin-induced andoxytocin-augmented labour. J Reprod Fertil 2000;120:91–7.

28. Sheiner E, Sarid L, Levy A, Seidman DS, Hallak M. Obstetric risk factors andoutcome of pregnancies complicated with early postpartum hemorrhage: apopulation-based study. J Matern Fetal Neonatal Med 2005;18:149–54

29. Baksu A, Kalan A, Ozkan A, Baksu B, Tekelioðlu M, Goker N. The effect ofplacental removal method and site of uterine repair on postcesarean endometritisand operative blood loss. Acta Obstet Gynecol Scand 2005;84:266–9.

30. Carroli G, Bergel E. Umbilical vein injection for management of retainedplacenta. Cochrane Database Syst Rev 2001;4.

31. Habek D, Frani�evi� D. Intraumbilical injection of uterotonics for retainedplacenta. Int J Gynaecol Obstet 2007;2:105–9.

32. B-Lynch C, Coker A, Lawal AH, Abu J, Cowen MJ. The B-Lynch surgicaltechnique for the control of massive postpartum haemorrhage: an alternative tohysterectomy? Five cases reported. Br J Obstet Gynaecol 1997;104:372–5.

33. Thomas BF. Uterine compression sutures for postpartum hemorrhage: efficacy,morbidity, and subsequent pregnancy. Obstet Gynecol 2007;110:68–71.



200811 obstetrics 1

Documents