ABSTRACT
Postpartum haemorrhage (PPH) is the common cause of obstetric haemorrhage and the leading cause of maternal deaths in Nigeria. Injectable uterotonics, which include ergometrine, oxytocin and syntometrine are the conventional drugs used and also remain the first line drug for prevention and treatment of PPH. However, these drugs are heat-sensitive when exposed to hot climates over long period of time which means they need to be refrigerated in order to maintain their potency. This may be difficult in low-resource settings or rural areas where electricity is very erratic.Misoprostol, another uterotonic that is available in tablet form, was thus approved by the Federal Ministry of Health. The purpose of this study was determine the knowledge and use of misoprostol in the prevention and treatment of Post-Partum haemorrhage. The research design was a descriptive survey method nd one hundred and fifty six primary health care workers that met the inclusion criteria across the twenty five facilities of Sabon Gari and Zaria local government area were included for the study. A validated questionnaire constructed by the researcher based on the guidelines on the use of misoprostol in the prevention an d treatment of Post-Partum haemorrhage was used for data collection. Information derived from the questionnaire was subjected to descriptive statistics and chi-square test of association. The findings from the study showed that only 31.3% of the respondents had high level of knowledge of misoprostol in the prevention and treatment of PPH and only 38.3% of the respondents had used misoprostol correctly for the prevention of PPH .For the treatment of PPH, findings revealed that only 16.3% of the respondents had used misoprostol correctly. Only about a quarter of the respondents (23.3%) had received training on the use of misoprostol and (27.3%) of the respondents claimed that the drug was always available in their facility. Knowledge of misoprostol was associated with the correct use of misoprostol for the prevention and treatment of PPH. Based on the findings the following recommendations were made; investment in training and retraining of primary health care workers on the use of misoprostol in the prevention and treatment of post-partum haemorrhage, monitoring and supervision of primary health care workers on the use of the drug and frequent supply and sustainable commodity management will be good mechanisms to improve availability of the drug and thus promote the frequent use of the drug.
CHAPTER ONE
INTRODUCTION
Background to the Study
Maternal mortality has been and still continues to be a public health problem particularly in developing countries. It is made more tragic because women die in the process of performing the essential physiologic function of childbearing and in efforts to fulfill their natural role of perpetuating the human race. According to WHO (2005), maternal mortality is the death of a woman while pregnant or within 42 days of termination of a pregnancy irrespective of the duration or site of the pregnancy from any cause related to or aggravated by the pregnancy or its management but not from accidental causes. Globally, an estimated 287 000 maternal deaths occurred in 2010, Sub-Saharan Africa (56%) and Southern Asia (29%) accounted for 85% of the global burden (245 000 maternal deaths) in 2010. At the country level, two countries account for a third of global maternal deaths: India at 19% (56 000) and Nigeria at 14% (40,000) (WHO,UNFPA, UNICEF & World Bank, 2012).
In Nigeria, the maternal mortality is estimated to be 545/100,000 live births (National Demography & Health Survey 2008). Indeed, the country has been ranked as the number two country (after India) with the highest absolute number of maternal death in the world. The causes of maternal mortality were reported in percentages as post partum haemorrhage (23%), infections (13%), unsafe abortion (13%), eclampsia (12%),obstructed labour (8%), other direct causes (8%) and indirect causes 20% (FMOH, 2007). Indirect causes such as malaria, anaemia, HIV/AIDS and cardiovascular disease complicate pregnancy or are aggravated by it (WHO, 2005).
Postpartum hemorrhage (PPH) is the common cause of obstetric haemorrhage and the leading cause of maternal death in Nigeria, as one in four maternal deaths is due to it (FMOH, 2007).According to the World Health Organization (WHO, 2000), PPH is defined as bleeding from the genital tract of 500 ml or more within the first 24 hours of delivery of the baby. Bleeding after delivery is normal; however excessive bleeding is often fatal. Uterine atony, which is the failure of the uterus to properly contract after delivery, is the commonest cause, accounting for about 90% cases of PPH (Chelmow, 2008). Other causes of PPH include tear in the cervix or vaginal tissue, uterine rupture, retained placenta or membrane, blood clotting disorders such as disseminated intravascular coagulation accounting for 10% of cases (FMOH, 2007).
The International Federation of Obstestrics and Gynaecology/International Council of Midwives (FIGO/ICM, 2006) recommended the use of active management of the third stage of labour (AMTSL) to prevent post partum haemorrhage. It involves the administration of a drug that causes the uterus to contract known as uterotonics, controlled cord traction only when a skilled attendant is present at birth and uterine massage after delivery of the placenta. Injectable uterotonics, which include ergometrine, oxytocin and syntometrine are the conventional drugs used and also remain the first line drug for prevention and treatment of PPH. However, these drugs are heat-sensitive when exposed to hot climates over long period of time which means they need to be refrigerated in order to maintain their potency. This may be difficult in low-resource settings or rural areas where electricity supply is very erratic and may be ineffective at preventing PPH and maternal mortality, sufficiently for Nigeria’s quest to accelerate pace towards MDG-5 target (FMOH, 2007).
Misoprostol, another uterotonic that is available in tablet form, was thus approved by the Federal Ministry of Health in 2007 for the prevention and treatment of PPH (FMOH, 2007). It has since been in increased use in obstetric and gynaecological practice, including the treatment of post partum haemorrhage. This is because it is relatively inexpensive, has alternative routes of administration (rectally, orally, and sublingually), is easy to store and is stable in field condition, has long shelf life of about 3 years and is easy to use with or without a skilled attendant (Prata, 2005). These characteristics make it very important and useful in rural settings where the efficacy of the other uterotonics (and injection safety) are not assured and the skilled birth attendants to administer the latter are even in short supply.
FIGO and ICM (2005), jointly recommend that in the absence of safe injection, oral misoprostol should be administered to prevent and treat post partum haemorrhage by a skilled birth attendant especially in rural areas. Therefore, there is need to promote misoprostol as an effective and easily administered drug for the prevention of PPH, and to ensure its ready availability in all settings where deliveries take place in the country especially in Primary health care facilities. This is because Primary Health Centres (PHCs) are the basic health care units in the country, and are located mainly in the rural communities where other categories of health facilities are few. Women needing delivery care first present in PHCs, and only when they experience severe complications are they referred to secondary or tertiary levels of care (Okonofua, 2010).
However, referral mechanisms between the different levels of care are not well developed in Nigeria and PPH being a rapidly developing phenomenon, may not be amenable to resolution even by prompt referral (Okonofua, 2010). Therefore, an effective approach to preventing maternal mortality associated with PPH is to ensure that efforts are put in place to effectively prevent or treat PPH in a timely fashion at childbirth. Thus the knowledge and use of misoprostol among nurses, midwives and community health workers, who are the principal delivery care providers of maternal health services at the primary level of care become necessary. This study is aimed at determining the knowledge and use of misoprostol in the prevention and treatment of post partum among primary health care workers in Zaria metropolis.
Statement of Problem
The Federal ministry of health, as part of her commitment to reducing maternal mortality due to PPH, trained selected health professionals fraom the 36 states and the FCT in the use of misoprostol for the reduction of maternal mortality (FMOH, 2011). Also, the department of Obstestrics and Gynaecology, Ahmadu Bello University Zaria in 2009 and 2010 in collaboration with University of California, Bekerley, trained primary health care providers in Zaria metropolis on the use of this drug in the prevention and treatment of post partum haemorrhage (Population & Reproductive Health Initiative, based at ABUTH, Zaria 2010).
The trainings were informed by the result of a community based study which showed that less than 5% of primary health care workers in the country have knowledge of the drug (Okonofua, 2008). Another study conducted in Benin revealed that only 24.2% of primary health care workers indicated that they had heard about misoprostol. However, when asked the route of administration and the dose for the prevention of PPH, only 5 (15.1%) respondents indicated correctly. Similarly, only 3 respondents correctly mentioned the route of administration of misoprostol for treatment of PPH but none could mention the correct dose for this purpose. Also, available records from primary health care facilities in Zaria metropolis showed that majority of the maternal deaths were as a result of PPH caused by uterine atony (Sabon-Gari Health Department, 2011). The researcher also observed that during the course of her practical experiences with students in the facilities that misoprostol was not commonly used by the health workers rather oxytocin and ergometrine were the commonly used drugs, despite the advantages of misoprostol (ease of storage, can be administered through multiple sites without the use of injection and has lower tendency to lose potency in tropical climate). Also, the researcher observed that primary care health workers do not use the correct recommended dose. The questions being raised in this study are how knowledgeable are the primary health workers in the use of misoprostol in the prevention and treatment of PPH and furthermore, does knowledge of misoprostol influence its use among primary health care workers? This study is geared towards finding answers to these questions.
Purpose of the Study
The purpose of this study was to determine the knowledge and use of misoprostol for the prevention and treatment of post partum haemorrhage among primary health care providers in Zaria metropolis.
Objectives of the Study
Specifically, the objectives of this study include to:-
- Determine the level of knowledge of misoprostol as a drug used in the prevention and treatment of PPH among primary health care workers in Zaria metropolis.
- Determine how primary health care workers use misoprostol in the prevention and treatment of post partum haemorrhage
- Identify factors influencing use of misoprostol for the prevention and treatment of post partum haemorrhage.
- Determine the relationship between knowledge of Misoprostol and the use of Misoprostol among the primary health care workers.
- Determine the relationship between some demographic characteristics such as age of respondents ,qualification, and years of experience and the knowledge of misoprostol.
Research Questions
- What is the level of knowledge of misoprostol in the prevention and treatment of post partum hemorrhage among primary health care workers in Zaria metropolis?
- How do Primary health care workers use misoprostol in the prevention and treatment of post partum hemorrhage?
- What are the factors influencing use of this drug?
- What is the relationship between knowledge of misoprostol and the practice of its use among the respondents?
- What is the relationship between some demographic characteristics of the respondents and their knowledge of misoprostol
Significance of the Study
The study is significant because it will provide information on the knowledge and use of misoprostol in the prevention and treatment of post partum haemorrhage among primary health care workers. The findings from the study when communicated will inform stakeholders thereby making a case for proper training of primary health care workers. Also such capacity building for primary health care workers on misoprostol use has the potential of preventing PPH, reducing complications of PPH, reducing number of referrals, especially in this setting where referral is weak and consequently reduction of maternal mortality. The result will be useful in promoting use of misoprostol for the prevention and treatment of post partum haemorrhage. The findings from this study will equally provide information on the factors influencing the use and non use of the drug among primary health care workers in the prevention and treatment of post partum haemorrhage. The identified factors when communicated will assist health policy makers, ministry officials, local government health officials, local and international organization and other government agencies in taking the proper steps to resolve the problems thus making the use of misoprostol correctly.
Finally information gathered from this study will serve as a source of literature and guide for future research and as well serve as empirical reference for further studies.
Scope of the Study
The study is limited to primary health care workers (Nurses, Midwives and community health extension workers) providing delivery services in Zaria metropolis. Specifically it is limited to Knowledge and use of misoprostol among primary health care workers in the prevention and treatment of post partum in Zaria metropolis .It is also confined to factors influencing use of misoprostol in the prevention and treatment of post partum haemorrhage among primary health care workers in Zaria Metropolis.
Operational Definition of Terms
Level of knowledge of Misoprostol: Refers to the respondents understanding of the class of the drug, routes of administration and dosages of the drug for both prevention and treatment of PPH, when the drug is administered, mechanism of action and side effects associated with the use of the drug. For the purpose of this study, knowledge of the respondents will be categorized in to three levels. Respondents scoring 80-100% will be graded as having high level of knowledge,50-79% as moderate level of Knowledge and 49% and below will be regarded as low level of knowledge.
Use of misoprostol for prevention and treatment of PPH: Refers to whether they have used the drug, how they used it, when they gave the drug, the dosage they administered for both prevention and treatment of post partum haemorrhage. It also refers to the correct use of misoprostol as stipulated by guidelines of the federal Ministry of health. For the purpose of this study respondents that have used misoprostol will be deemed to have used the drug correctly if the dosage and route of administration, timing for administration for prevention and treatment were accurately documented.
Factors influencing use: These refer to factors such as availability, supply, previous experience with the use of the drug, cost of the drug, health workers perception of effectiveness of the drug, e.t.c which can enhance or inhibit its utilization in the prevention and treatment of postpartum haemorrhage.
Primary Health care workers refer to nurses, midwives and community health workers who provide maternal and child health care delivery services in primary health care facilities.
Socio-demographic variables of the respondent: This refers to the age, qualification and years of working experience of the respondents.
CHAPTER TWO
LITERATURE REVIEW
The chapter dealt with the review of relevant literature. The relevant literature discussed were conceptual, theoretical and empirical review. The literature was concluded with a summary of the reviews.
OVERVIEW OF MATERNAL MORTALITY AND POST PARTUM HAEMORRHAGE
Maternal mortality also known as ‘maternal death’ or ‘obstetric death’ is the death of a woman during or shortly after a pregnancy. According to world Health Organization (WHO 2005), maternal mortality is defined as the death of a woman while pregnant or within forty-two days after the termination of pregnancy, irrespective of the duration and site of the pregnancy, from any cause related to or aggravated by the pregnancy or its management but not from accidental or incidental causes.
Globally, an estimated 287,000 maternal deaths occurred in 2010 (WHO, UNFPA, UNICEF & World Bank, 2012).Sub-Saharan Africa (56%) and Southern Asia (29%) accounted for 85% of the global burden (245,000 maternal deaths) in 2010. At the country level, two countries account for a third of global maternal deaths: India at 19% (56,000) and Nigeria at 14% (40, 000). The global MMR in 2010 was 210 maternal deaths per 100,000 live births, down from 400 maternal deaths per 100,000 live births in 1990. The MMR in developing regions (240) was 15 times higher than in developed regions (16). Sub-Saharan Africa had the highest MMR at 500 maternal deaths per 100,000 live births, while Eastern Asia had the lowest among MDG developing regions, at 37 maternal deaths per 100,000 live births. The MMRs of the remaining MDG developing regions, in descending order of maternal deaths per 100 000 live births are Southern Asia (220), Oceania (200), South-eastern Asia (150), Latin America and the Caribbean (80), Northern Africa (78), Western Asia (71) and the Caucasus and Central Asia (46) (WHO, UNFPA, UNICEF & World Bank, 2012).
This implies that more maternal deaths occur in countries in sub-Saharan Africa. This is because women in developing countries have many pregnancies on the average; their lifetime risk more accurately reflects the overall burden of these women (WHO, 2010). Lifetime risk is the probability that a woman will die from complications of pregnancy and childbirth over her lifetime; it takes into account both the maternal mortality ratio and the total fertility rate (probable number of births per woman during her reproductive years). Thus in a high-fertility setting a woman faces the risk of maternal death multiple times, and her lifetime risk of death will be higher than in a low-fertility setting. The lifetime risk of maternal death in the developing world in 2008 was 1 in 120, compared with industrialized regions with an estimated 1 in 4300 (WHO, 2010). Among the regions, women in sub-Saharan Africa faced the highest lifetime risk – 1 in 31 – followed by , South Asia – 1 in 110.
Post-partum hemorrhage was the leading cause of maternal mortality worldwide, accounting for about 34% of deaths, hypertension 18%,sepsis 8%,abortion 10%, embolism 1%, other direct causes 11% and indirect cause’s accounts for about 18% (WHO, 2010). According to the Kinney, Kerber, Black et al(2010) the picture in sub-Saharan Africa is similar to the global distribution of causes of death with haemorrhage accounting for about 34% of all maternal deaths.
Nigeria is the most populous country in Africa, 2% of the world’s population but contributes about 14% (40,000 maternal deaths) to the global estimates of maternal mortality (UNPA, WHO, 2012). The World Health Organization and the Federal Ministry of Health of Nigeria report that about 145 women died everyday in Nigeria as a result of causes related to childbirth and in terms of absolute numbers, Nigeria ranked second globally to India in number of maternal deaths. The risk of a woman dying from child birth was 1 in18 in Nigeria, compared to 1 in 61 for all developing countries, and 1 in 29,800 for Sweden (Nwosu, Odubanjo & Osinusi, 2009). The proportions of maternal deaths attributable to PPH varied considerably between developed and developing countries, suggesting that deaths from PPH are preventable.
Interventions to prevent PPH in developing countries are therefore pivotal in the global effort to achieve by 2015 the Millennium Development Goal of reducing maternal mortality ratio by three-quarters (from 1990 levels).
According to the NDHS (2008) maternal mortality ratio in Nigeria was 545/100,000 live births, with a wide regional variation. The MMR in Northern Region was consistently over 1,000 per 100,000 live birth compared to the MMR in the Southern Region, which was frequently below 300 per 100,000 live births (Northwest-1025,Northeast-1549,Southwest-165,Southeast-285). Also, MMR in rural areas was higher than that of the urban areas (Centre for reproductive rights, 2009). The wide regional variation is attributed to differences in a range of factors such as wealth indices, educational level, cultural practices, health care coverage and utilization (Ozumba, 2009). The main causes of maternal mortality in Nigeria are post- partum haemorrhage, accounting for 23% of deaths, post-partum infections accounting for 17%, and the trio of eclampsia, obstructed labour and complications of abortion each accounting for about 11% of deaths. Other indirect causes of maternal deaths include malaria and anaemia in pregnancy (FMOH, 2007).
Prevalence of Post Partum Haemorrhage
According to World Health Organization (WHO, 2000), PPH is defined as bleeding from the genital tract of 500 mls or more within the first 24 hours of delivery of the baby. PPH is the most common life- threatening complication of the third stage of labour. It can also be a cause of long-term severe morbidity, and approximately 12% of women who survive PPH will have severe anemia (Abou-Zahr, 2003; WHO, 2006). Additionally, women who have severe PPH and survive (“near misses”) are significantly more likely to die in the year following the PPH (Carrolli, 2007).
Postpartum haemorrhage (PPH) is the leading cause of maternal mortality worldwide with a prevalence rate of approximately 6%; Africa has the highest prevalence rate of about 10.5% Considerable variations were also recorded for different regions of the world ranging from 2.55% in Asia to 10.5% in Africa although the rates were comparable for Europe (6.38%), Latin America and the Caribbean (8.90%), Northern America (6.37%) and Oceania (7.68%). However, these regional differences are not a direct reflection of the magnitude and risk of PPH-related maternal death which are largely determined by the availability of skilled birth attendants and facilities needed to save women’s lives. The risk of maternal death from PPH in developing countries is estimated to be one in 1000 deliveries compared with developing countries such as the UK, where the risk is estimated to be less than one in 100,000 deliveries (CMACE, 2011).
In Nigeria, PPH is the most common cause of maternal deaths accounting for about 23% of all maternal deaths (FMOH, 2007). Thus, efforts to achieve the fifth Millennium Development Goal must therefore include aggressive interventions to reduce PPH-related death. Although specific studies on postpartum haemorrhage in Nigeria are scanty, the contribution of postpartum haemorrhage to maternal mortality is well documented. Balachandran (2005) in Kaduna, Northern Nigeria documented postpartum haemorrhage as the most common cause of maternal mortality, accounting for 25% of all maternal deaths. Adewunmi’s (1986) reported that postpartum haemorrhage contributed to 18.7% of maternal mortality in Ibadan.
Another study from Eastern Nigeria reported 2.72% incidence and a case fatality rate of 3.25% for postpartum haemorrhage (Anya, 1999) .A study conducted in Jos revealed post partum haemorrhage to be the leading cause of maternal deaths accounting for about 34% of all the cases (Ujah, Aisien, Mutihir, Vanderjag, Glew & Uguru, 2005).
Morbidity and mortality due to PPH are largely preventable through skilled care during childbirth. However, delays in identifying haemorrhage, delays in transport to the appropriate point of care, and delays in receiving the recommended treatment all contribute to high rates of maternal mortality and morbidity due to PPH (Okonofua, 2010). In some cases, women may give birth in facilities where skilled birth attendants lack the necessary skills, equipment, or supplies to prevent and manage PPH and shock, thus leading to increase in the cases of PPH. Hence if health workers especially those working in the primary health facility are equipped with evidenced based knowledge on the prevention and treatment of post partum haemorrhage there will be less need for referral to secondary or tertiary health care facility (Okonofua,2010).
OVERVIEW OF ANATOMY AND PHYSIOLOGY OF THE UTERUS
Anatomically, the uterus consists of three divisions: the body or corpus, the isthmus, and the cervix. The body of the uterus is the uppermost part and forms the bulk of the organ. The lining of the cavity is continuous with that of the fallopian tubes, which enter at its upper aspects (the cornua). During pregnancy, the body of the uterus is the portion of the structure that expands to contain the growing fetus. The portion of the uterus between the points of attachment of the fallopian tubes is termed the fundus.
The fundus is also the portion that can be palpated abdominally to determine the amount of uterine growth occurring during pregnancy, to measure the force of uterine contractions during labor, and to assess that the uterus is returning to its non pregnant state after childbirth. The isthmus of the uterus is a short segment between the body and the cervix. In the non pregnant uterus, it is only1 to 2 mm in length. During pregnancy, this portion also enlarges greatly to aid in accommodating the growing fetus. It is the portion of the uterus that is most commonly cut when a fetus is born by a cesarean birth.
The cervix is the lowest portion of the uterus. It represents approximately one third of the total uterus size and is approximately2 to 5 cm long. Approximately half of it lies above the vagina and half extends into the vagina. Its central cavity is termed the cervical canal. The opening of the canal at the junction of the cervix and isthmus is the internal cervicalos; the distal opening to the vagina is the external cervical os. The level of the external os is at the level of the Ischia spines (an important relationship in estimating the level of the fetus in the birth canal).
Uterine and Cervical Coats
The uterine wall consists of three separate coats or layers of tissue: an inner one of mucous membrane (the endometrium), a middle one of muscle fibers (the myometrium), and an outer one of connective tissue (the perimetrium).The endometrium layer of the uterus is the one that is important for menstrual function. It is formed by two layers of cells. The layer closest to the uterine wall, the basal layer, remains stable, uninfluenced by hormones. In contrast, the inner glandular layer is greatly influenced by both oestrogen and progesterone. It grows and becomes so thick and responsive each month under the influence of estrogen and progesterone that it is capable of supporting a pregnancy. If pregnancy does not occur, this is the layer that is shed as the menstrual flow. The mucous membrane lining the cervix is termed the endocervix.
The endocervix, continuous with the endometrium, is also affected by hormones, but changes are manifested in a more subtle way. The cells of the cervical lining secrete mucus to provide a lubricated surface so that spermatozoa can readily pass through the cervix; the efficiency of this lubrication increases or wanes depending on hormone stimulation. At the point in the menstrual cycle when oestrogen production is at its peak, as much as 700 mls of mucus per day is produced; at the point that oestrogen is very low, only few millilitres are produced. Because mucus is alkaline, it helps to decrease the acidity of the upper vagina, aiding in sperm survival. During pregnancy, the endocervix becomes plugged with mucus, forming a seal to keep out ascending infections (the operculum).The lower surface of the cervix and the lower third of the cervical canal are lined not with mucous membrane but with stratified squamous epithelium, similar to that lining the vagina.
The myometrium, or muscle layer of the uterus, is composed of three interwoven layers of smooth muscle, the fibers of which are arranged in longitudinal, transverse, and oblique directions. This network offers extreme strength to the organ. The myometrium serves the important function of constricting the tubal junctions and preventing regurgitation of menstrual blood into the tubes. It also holds the internal cervical os closed during pregnancy to prevent a preterm birth. When the uterus contracts at the end of pregnancy to expel the fetus, equal pressure is exerted at all points throughout the cavity because of its unique arrangement of muscle fibers. After childbirth, this interlacing network of fibers is able to constrict the blood vessels, thereby limiting the loss of blood in the woman (McCance & Heuther, 2007).
The perimetrium, or the outermost layer of the uterus, serves the purpose of adding strength and support to the structure (Pelliteri, 2006).
Uterine Blood Supply
The large descending abdominal aorta divides to form two iliac arteries; main divisions of the iliac arteries are the hypogastric arteries. These further divide to form the uterine arteries and supply the uterus. Because the uterine blood supply is not far removed from the aorta, it is copious and adequate to supply the growing needs of a foetus. As an additional safeguard, after supplying the ovary with blood, the ovarian artery (a direct subdivision of the aorta) joins the uterine artery as a fail-safe system to ensure that the uterus will have an adequate blood supply. The blood vessels that supply the cells and lining of the uterus are tortuous against the sides of the uterine body in non-pregnant women.
As the uterus enlarges with pregnancy, the vessels “unwind” and so can stretch to maintain an adequate blood supply as the organ enlarges. The uterine veins follow the same twisting course as the arteries; they empty into the internal iliac veins.
After the baby is born, the muscles of the uterus contract, helping the placenta to separate from the uterine wall. The amount of blood lost depends on how quickly this happens, since the uterus can contract more effectively after the placenta is expelled. If the uterus does not contract normally (such as in uterine atony), the blood vessels at the placental site stay open and haemorrhage results. Because the estimated blood flow to the uterus is 500 to 800 mls/minute at term, most of which passes through the placenta, severe post partum haemorrhage can occur within just a few minutes. The muscle fibers of the uterus are in a crosshatch (criss-cross) pattern surrounding maternal blood vessels (Figure 1). After the birth of the baby, these muscle fibers begin to contract and retract. Oxytocin, a hormone secreted by the posterior pituitary gland, stimulates uterine contents of the placenta to separate from the uterine wall. Placental separation occurs by contraction and retraction of the uterine muscles, reducing the size of the placental area. This reduction in size of the uterus is caused by retraction of the uterine muscles, a unique characteristic that helps maintain its shortened length after each contraction.
As the placental area becomes smaller, the placenta begins to separate from the uterine wall because, unlike the uterus, it is not elastic and cannot contract and retract. At the area where the placenta separates from the uterus a clot forms. This clot – known as a retro placental clot – collects between the uterine wall and the placenta and further promotes separation.
Additional uterine contractions complete the separation of the placenta from the uterine wall. The placenta descends into the lower uterine segment and into the vagina where it is expelled.
After separation:
- The placental site is rapidly covered by a fibrin net and clots form.
- The muscle fibers of the uterus compress the blood vessels where the placenta was attached, helping to control bleeding at the placental site.
- The uterus continues to contract, forcing the placenta and membranes to fall into the lower uterine segment. With the delivery of the placenta, the uterus is able to contract completely (Pelliteri, 2006).
PATHOPHYSIOLOGY OF POST-PARTUM HAEMORRHAGE
At term, the uterus and placenta receive 500-800 mls of blood per minute through their low resistance network of vessels. This high flow predisposes a gravid uterus to significant bleeding if not well physiologically or medically controlled. By the third trimester, maternal blood volume increases by 50%, which increases the body’s tolerance of blood loss during delivery. Following delivery of the fetus, the gravid uterus is able to contract down significantly given the reduction in volume. This allows the placenta to separate from the uterine interface, exposing maternal blood vessels that interface with the placental surface. After separation and delivery of the placenta, the uterus initiates a process of contraction and retraction, shortening its fiber and kinking the supplying blood vessels, like physiologic sutures or “living ligatures”.
If the uterus fails to contract, or the placenta fails to separate or deliver, then significant haemorrhage may ensue. Uterine atony, or diminished myometrial contractility, accounts for 90% of postpartum hemorrhage (Pelliteri, 2006).
Causes and Risk factor of Post Partum Haemorrhage
According to Ujah & Ejeh (2005) post partum haemorrhage is most commonly caused by uterine atony in Nigeria as in other parts of the world. It accounts for 70-80% of the cases (FMOH, 2011).
Koh, Devendra & Tan (2009) report that there are several possible reasons for severe bleeding during and after the third stage of labour which includes uterine atony (failure of the uterus to contract properly after delivery), trauma (cervical, vaginal, or perineal lacerations), retained or adherent placental tissue, clotting disorders, and inverted or ruptured uterus. More than one of these can cause postpartum haemorrhage in any given woman.
Recognised risk factors to uterine atony include pre-eclampsia, prolonged or augmented labour, large baby or multiple foetuses, high parity and use of halogenated anaesthetic agents prior to delivery (Tsu, 2004). An important predisposing factor that cuts across all causes of PPH is anaemia in pregnancy and labour. Anaemia increases the risk of dying from PPH because blood loss that could readily be tolerated by women with normal haemoglobin levels could be fatal for an anaemic woman. In spite of the long list of risk factors in the literature, most PPH cases occur in women without any identifiable risk factors and thus preventive measures are recommended for all women giving birth (WHO, 2005).
Management of post partum haemorrhage
The specific time at which PPH occurs is during the third stage of labour (after delivery of the baby and until complete delivery of the placenta), when the uterus may suddenly lose its ability to contract. Indeed uterine atony is the biggest cause of PPH worldwide (WHO, 2007). Also, predicting who will have PPH based on risk factors is difficult because two thirds of women who have PPH had no preceding risk factors (JHPIEGO, 2001). Therefore, all women are considered at risk and PPH prevention must be incorporated into care provided at every birth.
An evidence based intervention that is universally recommended for PPH prevention is active management of third stage of labour (AMTSL) (WHO, 2007 and FMOH, 2011). The World Health Organization (WHO, 2007) currently recommends that AMTSL should be performed only by skilled attendants and offered to all women who are giving birth.
It is a set of inter locking intervention that includes the administration of an uterotonic one minute after birth, control cord traction and uterine massage (Fawole, Awolude, Adenija & Onafowokan, 2010). It shortens the duration of the third stage of labour, thus decreasing blood loss after delivery and should be performed by a skilled birth attendant. It also helps in preventing about 60% of PPH as a result of uterine atony (FMOH, 2011).
Uterotonics are pharmacological agents that help to induce contraction of the uterus. According to Okonofua (2011), administration of a potent uterotonic drug will prevent severe haemorrhage and reduce the likelihood of maternal mortality when uterine atony occurs. WHO (2005) also recommends the use of intravenous oxytocin or ergometrine as first or second line drugs, respectively for the prevention and treatment of uterine atony that leads to PPH.
However, there are limitations to the routine in all settings especially in primary health care setting. Firstly they can only be administered by parenteral injections and may be expensive especially when the cost of purchasing syringes, needles and antiseptics are added to the computations. Secondly, the drugs have short half lives as 80% of their potency could be lost by inappropriate storage especially in low resource settings. It is within this context that misoprostol, an analogue of prostaglandin, has advantages over oxytocin and ergometrine (Okonofua, 2010).