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2A.3 Post-partum hemorrhage
Extended Abstracts / Thrombosis Research 119 Suppl. 1 (2007) S1–S96
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2A.3 Post-partum hemorrhage C. McLintock *. Department of Obstetrics and Gynaecology, National Women’s Health, Auckland City Hospital, New Zealand Every year, an estimated 529,000 women die as a result of complications of childbirth [1]. The socalled “Big Five” direct causes of maternal death are hemorrhage, sepsis, eclampsia, obstructed labor and unsafe abortion. Hemorrhage it the most common cause of maternal death worldwide accounting for about 150,000 deaths annually. The marked disparity between the maternal mortality rate in industrialized countries and resource poor countries is well recognised; over half of maternal deaths due to hemorrhage occur in sub-Saharan Africa and another third in Asia. On a global scale the UK maternal mortality ratio due to hemorrhage of 8.5 per 100,000 maternities [2,3] pales into insignificance when compared to the estimated mortality rate from hemorrhage in sub-Saharan Africa of 300 per 100,000 live births. However, it is sobering to note that of the 17 women who died of hemorrhage in the UK in the last triennial, the majority were thought to have received substandard care. Postpartum hemorrhage is responsible for the majority of maternal deaths due to hemorrhage and is defined as blood loss in excess of the average loss following a normal vaginal delivery, namely >500 ml [3], occurring in 15 19% of pregnancies in developed countries. The majority of healthy pregnant women can easily accommodate this degree of blood loss as it represents a loss of only around 10% of the circulating maternal blood volume at term. A more clinically relevant definition of postpartum hemorrhage that is likely to be associated with increased maternal morbidity, is blood loss of >1000 ml occurring in about 2 4% of pregnancies [4,5]. However, in otherwise healthy women who do not have pre-existing anemia, even this degree of blood loss is well tolerated with a slight increase in heart rate being the only notable sign of significant blood loss. By the time a woman develops a hypotensive response to blood loss, as much as 1500 ml, equivalent to one quarter of the circulating blood volume, may have been lost. Given a blood flow of 600 800 ml/min to the uterine spiral arteries at term, it can easily be appreciated how rapidly such massive blood loss can occur. The significant morbidity and mortality associated with postpartum hemorrhage is due in part to a lack of recognition of the severity of maternal blood loss. Maternal risk factors for postpartum hemorrhage that can be identified in the antenatal period include previous PPH, maternal obesity, a maternal
Table 1. Risk factors for postpartum hemorrhage that can be identified antenatally Previous postpartum hemorrhage Antepartum hemorrhage Placental abruption Placental previa Multiple pregnancy Macrosomic infant (>4 kg) Previous uterine surgery including CS Maternal obesity Maternal anticoagulation
bleeding disorder; as can a number of pregnancyspecific problems; a macrosomic fetus, placenta previa, or multiple pregnancy, Table 1. Delivery complications such as prolonged labour (>12 hours), a prolonged third stage of labour, retained placenta, especially following induction of labour, and also genital tract injury in particular after instrumental delivery all increase the risk of PPH, Table 2. Prediction of which women will have PPH is not always possible and as uterine atony is a major contributing factor to hemorrhage; all women should have active management of the 3rd stage of labour with an ecbolic agent such as syntocinon. Women with placenta previa who have had previous uterine surgery are at particularly high risk of having placenta accreta i.e. morbid attachment of the placenta to the uterine wall that is associated with a significant risk of massive, rapid hemorrhage and should be delivered by experienced consultant staff. Other recommendations from Confidential Enquiries into Maternal Deaths report are listed in Table 3. Contemporary definitions of massive blood loss include either loss a rate of blood loss exceeding 150 ml/min or loss of 50% blood volume within a 3 hour period [6]. A key factor in management of critical hemorrhage is early recognition of the problem to prevent hypoperfusion of the microcirculation. Clinical vigilance, regularly assessing blood loss, monitoring basic observations such as heart rate and blood pressure will identify clinically important bleeding before the circulating blood volume gets too low. Early resuscitation with crystalloids and blood products is important but a methodical investigation of the potential cause or causes of hemorrhage must be carried out at the same time. In addition to examining for and treating uterine atony or retained placenta or genital tract trauma, an early coagulation screen may help detect an unanticipated, pre-existing
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2nd Int. Symp. on Women’s Health Issues in Thrombosis and Haemostasis / Thrombosis Research 119 Suppl. 1 (2007) S1–S96 Table 2. Intrapartum risk factors for postpartum hemorrhage Uterine Atony
Uterine, cervical or vaginal injury
Coagulopathy
Multiple pregnancy Polyhydramnios Baby >4 kg Prolonged labour >12 h Prolonged 3rd stage (>30 min) Retained placenta Febrile illness
Instrumental delivery Caesarean section esp. emergency
Amniotic fluid embolism Placental abruption
Table 3. Essential steps in women identified at high-risk of postpartum hemorrhage [8] • women should be screened and treated for anaemia pre-partum • all elective and emergency surgery should be performed by an experienced consultant that any anaesthetic should be given by a consultant anaesthetist • adequate intravenous access (two large bore cannulae) should be established before surgery starts • women should be delivered in a unit with facilities for blood transfusion and intensive care • active management of the 3rd stage of labour is essential • if bleeding is excessive the obstetrician should consider embolisation of uterine arteries by an interventional radiologist or further surgical procedures and should call for immediate assistance from a colleague or vascular surgeon if they do not feel competent to perform the required procedure • a consultant haematologist should be consulted for advice regarding transfusion requirements in cases of massive transfusion or disseminated intravascular coagulation (DIC) • A multidisciplinary massive hemorrhage protocol should be available in all units and updated and rehearsed regularly in conjunction with the blood bank.
coagulopathy due to amniotic fluid embolism or placental abruption. Prostaglandin analogues are the uterotonic agents of choice when uterine contraction cannot be maintained by oxytocic agents. Misoprostol, a prostaglandin E1 analogue, promises to play an important role in the management of PPH especially in low resource countries. Unlike other prostaglandins it is cheap, heat-stable, has a long shelf-life and can be given orally, rectally or vaginally and does not need to be administered by skilled birth attendants. A recent study carried out in India, has shown that oral misoprostol reduced the rate of acute postpartum haemorrhage and mean blood loss [7]. Postpartum hemorrhage remains an important cause of maternal death. The disparity between the absolute numbers of mothers who die as a result of
hemorrhage in developed and developing countries should not detract from the application of key approaches in the attempt to reduce the number of women who die in childbirth. These include education of birth attendants to be aware of the ever-present risk, identification of women at increased risk, early recognition and treatment of significant hemorrhage when it occurs and development of health systems to allow timely transfer of the sickest women to centres that can provide the necessary care. The challenge is to customise strategies so that they are appropriate for and applicable to the countries they are developed for.
Reference(s) [1] Maternal Mortality in 2000: Estimates developed by WHO, UNICEF, UNFPA; 2004. [2] World Health Organisation. Technical working group: care in normal birth: a practical guide. Geneva; 1996. [3] CEMACH. Why mothers die. Report on Confidential enquiries into maternal deaths in the United Kingdom. London: RCOG Press, 2004. [4] Bais JMJ, Eskes M, Pel M, et al. Postpartum haemorrhage in nulliparous women: incidence and risk factors in low and high risk women. A Dutch population-based cohort study on standard (500 ml) and severe (1000 ml) postpartum haemorrhage. Eur J Obstet Gynecol Reprod Biol 2004; 115: 166 72. [5] Stones RW, Paxton CM, Saunders NS. Risk factors for major obstetric haemorrhage. Eur J Obstet Gynecol Reprod Biol 1999; 48: 15 8. [6] Macphail S, Talks K. Massive post-partum haemorrhage and management of disseminated intravascular coagulation. Curr Obstet Gynaecol 2004; 14(2): 123 31. [7] Derman RJ, Kodkany BS, Goudar SS, et al. Oral misoprostol in preventing postpartum haemorrhage in resource-poor communities: a randomised controlled trial. Lancet 2006; 368: 1248 53. [8] National Institute for Clinical Excellence. Why mothers die: Confidential enquiries into maternal deaths 2001. London: RCOG Press, 2001.
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2A.3 Post-partum hemorrhage C. McLintock *. Department of Obstetrics and Gynaecology, National Women’s Health, Auckland City Hospital, New Zealand Every year, an estimated 529,000 women die as a result of complications of childbirth [1]. The socalled “Big Five” direct causes of maternal death are hemorrhage, sepsis, eclampsia, obstructed labor and unsafe abortion. Hemorrhage it the most common cause of maternal death worldwide accounting for about 150,000 deaths annually. The marked disparity between the maternal mortality rate in industrialized countries and resource poor countries is well recognised; over half of maternal deaths due to hemorrhage occur in sub-Saharan Africa and another third in Asia. On a global scale the UK maternal mortality ratio due to hemorrhage of 8.5 per 100,000 maternities [2,3] pales into insignificance when compared to the estimated mortality rate from hemorrhage in sub-Saharan Africa of 300 per 100,000 live births. However, it is sobering to note that of the 17 women who died of hemorrhage in the UK in the last triennial, the majority were thought to have received substandard care. Postpartum hemorrhage is responsible for the majority of maternal deaths due to hemorrhage and is defined as blood loss in excess of the average loss following a normal vaginal delivery, namely >500 ml [3], occurring in 15 19% of pregnancies in developed countries. The majority of healthy pregnant women can easily accommodate this degree of blood loss as it represents a loss of only around 10% of the circulating maternal blood volume at term. A more clinically relevant definition of postpartum hemorrhage that is likely to be associated with increased maternal morbidity, is blood loss of >1000 ml occurring in about 2 4% of pregnancies [4,5]. However, in otherwise healthy women who do not have pre-existing anemia, even this degree of blood loss is well tolerated with a slight increase in heart rate being the only notable sign of significant blood loss. By the time a woman develops a hypotensive response to blood loss, as much as 1500 ml, equivalent to one quarter of the circulating blood volume, may have been lost. Given a blood flow of 600 800 ml/min to the uterine spiral arteries at term, it can easily be appreciated how rapidly such massive blood loss can occur. The significant morbidity and mortality associated with postpartum hemorrhage is due in part to a lack of recognition of the severity of maternal blood loss. Maternal risk factors for postpartum hemorrhage that can be identified in the antenatal period include previous PPH, maternal obesity, a maternal
Table 1. Risk factors for postpartum hemorrhage that can be identified antenatally Previous postpartum hemorrhage Antepartum hemorrhage Placental abruption Placental previa Multiple pregnancy Macrosomic infant (>4 kg) Previous uterine surgery including CS Maternal obesity Maternal anticoagulation
bleeding disorder; as can a number of pregnancyspecific problems; a macrosomic fetus, placenta previa, or multiple pregnancy, Table 1. Delivery complications such as prolonged labour (>12 hours), a prolonged third stage of labour, retained placenta, especially following induction of labour, and also genital tract injury in particular after instrumental delivery all increase the risk of PPH, Table 2. Prediction of which women will have PPH is not always possible and as uterine atony is a major contributing factor to hemorrhage; all women should have active management of the 3rd stage of labour with an ecbolic agent such as syntocinon. Women with placenta previa who have had previous uterine surgery are at particularly high risk of having placenta accreta i.e. morbid attachment of the placenta to the uterine wall that is associated with a significant risk of massive, rapid hemorrhage and should be delivered by experienced consultant staff. Other recommendations from Confidential Enquiries into Maternal Deaths report are listed in Table 3. Contemporary definitions of massive blood loss include either loss a rate of blood loss exceeding 150 ml/min or loss of 50% blood volume within a 3 hour period [6]. A key factor in management of critical hemorrhage is early recognition of the problem to prevent hypoperfusion of the microcirculation. Clinical vigilance, regularly assessing blood loss, monitoring basic observations such as heart rate and blood pressure will identify clinically important bleeding before the circulating blood volume gets too low. Early resuscitation with crystalloids and blood products is important but a methodical investigation of the potential cause or causes of hemorrhage must be carried out at the same time. In addition to examining for and treating uterine atony or retained placenta or genital tract trauma, an early coagulation screen may help detect an unanticipated, pre-existing
S18
2nd Int. Symp. on Women’s Health Issues in Thrombosis and Haemostasis / Thrombosis Research 119 Suppl. 1 (2007) S1–S96 Table 2. Intrapartum risk factors for postpartum hemorrhage Uterine Atony
Uterine, cervical or vaginal injury
Coagulopathy
Multiple pregnancy Polyhydramnios Baby >4 kg Prolonged labour >12 h Prolonged 3rd stage (>30 min) Retained placenta Febrile illness
Instrumental delivery Caesarean section esp. emergency
Amniotic fluid embolism Placental abruption
Table 3. Essential steps in women identified at high-risk of postpartum hemorrhage [8] • women should be screened and treated for anaemia pre-partum • all elective and emergency surgery should be performed by an experienced consultant that any anaesthetic should be given by a consultant anaesthetist • adequate intravenous access (two large bore cannulae) should be established before surgery starts • women should be delivered in a unit with facilities for blood transfusion and intensive care • active management of the 3rd stage of labour is essential • if bleeding is excessive the obstetrician should consider embolisation of uterine arteries by an interventional radiologist or further surgical procedures and should call for immediate assistance from a colleague or vascular surgeon if they do not feel competent to perform the required procedure • a consultant haematologist should be consulted for advice regarding transfusion requirements in cases of massive transfusion or disseminated intravascular coagulation (DIC) • A multidisciplinary massive hemorrhage protocol should be available in all units and updated and rehearsed regularly in conjunction with the blood bank.
coagulopathy due to amniotic fluid embolism or placental abruption. Prostaglandin analogues are the uterotonic agents of choice when uterine contraction cannot be maintained by oxytocic agents. Misoprostol, a prostaglandin E1 analogue, promises to play an important role in the management of PPH especially in low resource countries. Unlike other prostaglandins it is cheap, heat-stable, has a long shelf-life and can be given orally, rectally or vaginally and does not need to be administered by skilled birth attendants. A recent study carried out in India, has shown that oral misoprostol reduced the rate of acute postpartum haemorrhage and mean blood loss [7]. Postpartum hemorrhage remains an important cause of maternal death. The disparity between the absolute numbers of mothers who die as a result of
hemorrhage in developed and developing countries should not detract from the application of key approaches in the attempt to reduce the number of women who die in childbirth. These include education of birth attendants to be aware of the ever-present risk, identification of women at increased risk, early recognition and treatment of significant hemorrhage when it occurs and development of health systems to allow timely transfer of the sickest women to centres that can provide the necessary care. The challenge is to customise strategies so that they are appropriate for and applicable to the countries they are developed for.
Reference(s) [1] Maternal Mortality in 2000: Estimates developed by WHO, UNICEF, UNFPA; 2004. [2] World Health Organisation. Technical working group: care in normal birth: a practical guide. Geneva; 1996. [3] CEMACH. Why mothers die. Report on Confidential enquiries into maternal deaths in the United Kingdom. London: RCOG Press, 2004. [4] Bais JMJ, Eskes M, Pel M, et al. Postpartum haemorrhage in nulliparous women: incidence and risk factors in low and high risk women. A Dutch population-based cohort study on standard (500 ml) and severe (1000 ml) postpartum haemorrhage. Eur J Obstet Gynecol Reprod Biol 2004; 115: 166 72. [5] Stones RW, Paxton CM, Saunders NS. Risk factors for major obstetric haemorrhage. Eur J Obstet Gynecol Reprod Biol 1999; 48: 15 8. [6] Macphail S, Talks K. Massive post-partum haemorrhage and management of disseminated intravascular coagulation. Curr Obstet Gynaecol 2004; 14(2): 123 31. [7] Derman RJ, Kodkany BS, Goudar SS, et al. Oral misoprostol in preventing postpartum haemorrhage in resource-poor communities: a randomised controlled trial. Lancet 2006; 368: 1248 53. [8] National Institute for Clinical Excellence. Why mothers die: Confidential enquiries into maternal deaths 2001. London: RCOG Press, 2001.