Classification of Post-Delivery Haemorrhage
When evaluating postpartum haemorrhages, it is necessary to examine in two separate sections in terms of timing,
1) early bleeding: identifies the first 24 hours
2) secondary postpartum hemorrhage: defines between the first 24 hours and the first six weeks.
Let’s start with early bleeding.
This period mainly concerns the separation of the placenta, which is the third stage of birth, and the time after it. When this period is considered physiologically, myometrium, the muscle tissue of the uterus, and the decidua, which assumes the bed of pregnancy are arranged to provide bleeding control following contraction. In the third stage, contractions are strong and long-lasting. With the effect of these contractions, the blood flow to the placenta is stopped and the placenta and its attachments are separated.
There are two different localizations regarding the separation of the placenta. Bleeding occurs in the central part of the placenta in Schultze type separation, which includes a majority of 80%. In Duncan type separation, which occurs at 20% frequency, the separation starts from the edge and is thought to cause relatively more bleeding. Since it is not possible to predict and interfere with the type of weathering in clinical practice, this distinction has no meaning for women.
In the process of separation of the placenta and afterwards, myometrium, the muscle tissue of the uterus, contracts, and the muscle fibers act as a ‘live node’ and close the lumens, their cavities and mouths by pressing the small arteries and veins. At the same time, it is thought that bleeding control is achieved by contracting the uterus and pressing one of the walls to another.
Its mechanical function, which provides postpartum contraction and bleeding control, basically assumes two hormones:
In general definition oxytocin provides uterine contraction by acting on oxytocin receptors. It has been used as a therapeutic agent in postpartum haemorrhage with this mechanism for a long time.
During labor, oxytocin is secreted in waves. The frequency and duration of these fluctuations increase steadily. Although the mechanism of its formation is unknown, the number of oxytocin receptors in the muscle tissue of the uterus increases during pregnancy and labour.
For many years, oxytocin has been used successfully to prevent and treat postpartum haemorrhage. However, the use of oxytocin to increase uterine contractions during labour also increases the likelihood of bleeding, which we refer to as atonia bleeding in the third stage of the action. Probably this is due to the reduction of oxytocin receptor sensitivity by the constant delivery of oxytocin released physiologically into attacks. Indication and duration of use of oxytocin, which we know as artificial pain, should be adjusted so as not to cause postpartum atony and should not be used outside the indication.
The best known prostaglandins, the second hormone, are prostaglandin F and prostaglandin E2 alpha. Prostaglandins produced in the decidua tissue, placenta and membranes in the uterus cause severe contraction in the uterine muscle fibers called myometrium. The contractile creative effect of this group of hormones does not depend on the week of gestation. In many studies, it is stated that high amounts of prostaglandin are secreted in the third stage of birth and the membranes are the main production site.
It has been shown that oxytocin and prostaglandins work together and interact in controlling the onset of labour and postpartum haemorrhage.
The effectiveness of the coagulation mechanism should be emphasized in the physiology of postpartum haemorrhage control. Sensitive changes occur on substances that cause clotting and melt the clot before and after birth. The main factor to prevent postpartum haemorrhage is blockage of small artery mouths with clot plugs. A rare factor VIII deficiency is observed in the rare Von Willebrand disease and the postpartum haemorrhage rate reaches 15%.
Atony constitutes 75-90% of postpartum haemorrhage causes. In 20%, why? birth canal injuries (rupture; rupture of the uterus, inversion: reversal of the uterus like a glove finger and ruptures of the birth canal). Congenital or acquired coagulation disorders come in 3%.
It occurs because the uterus does not contract after birth and cannot close the vessels in the vein. However, if it is thought that 1000 ml of blood passes in the placenta in the last stages of pregnancy, this amount will express 1/5 of the blood available in the circulation of the woman. In this way, it seems clear that atony bleeding will be a serious emergency.
The most important reason for increasing the frequency is having atony bleeding before (relative risk is around 3.3%).
The inability of the uterus to contract may be closely related to the placental parts remaining inside. These fragments can remain cleaved from the placenta, or may be related to the separate tiny placental fragment, called the succinate lobe. The remaining placental parts reveal mechanical resistance to uterine contraction, preventing the muscles from contracting, and the vessels remain open. However, the reason for the placental parts to remain inside in most cases is the ineffective and irregular contraction of the uterus. Therefore, placenta fragments may remain inside as a result of inevitable bleeding.
Conditions such as multiple pregnancy, polyhydramnios that cause stretching of the uterus before birth and myomas that cause tension in the 3rd stage also increase the risk of atony bleeding. In these cases that cause tension, ineffective and irregular uterine contractions after birth increase the possibility of atony.
Although rarely encountered, the placenta behind the placenta called ablatio placenta leaks between the muscle fibers of the uterus outside the vein and disrupts the contraction order by creating the condition called ‘couvelaire’ uterus and may cause atony.
The infection table of amniotic fluid and membranes called chorioamnionitis will appear as a cause of postpartum atony by disrupting the regular and effective contraction mechanism of muscle fibers in the uterus.
Prolonged labour also causes oxytocin receptor saturation, increasing the frequency of atony bleeding.
Placement anomalies of the placenta, which is one of the factors that cause bleeding after birth, will be explained in the link in its name.
In the management of postpartum haemorrhages, the woman’s blood loss should be eliminated and the cause of the bleeding should be mastered first. In addition to cause-oriented therapy, oxytocin and prostaglandins not found in our country are used. Meanwhile, blood and blood products need to be supplied quickly. If bleeding cannot be mastered by medical treatments, surgical treatment may require life-saving interventions ranging from hypogastric artery attachment to hysterectomy.
Secondary Postpartum Haemorrhage
There is no standard definition for the amount of bleeding in this period of bleeding, which covers between the first 24 hours and between 6 weeks. It shows a spectrum, the amount of which varies slightly from postpartum haemorrhage to severe bleeding. Its frequency is around 1%.
As with primary postpartum haemorrhages, the most common cause of secondary postpartum haemorrhages is uterine atony. The two most common causes of atony are either rest placenta or infection of the intrauterine tissue (endometritis). In the first one, the placenta fragments must be cleaned, and in the second one, effective, protocol-compatible and broad-spectrum antibiotic treatments should be performed. The smelly discharge in the endometritis table is the detection of uterine sensitivity during fever and examination in the mother. Laboratory findings will also help in diagnosis. Differential diagnosis between the two conditions can be difficult at times and the two conditions can coexist at the same time.
Important causes of late haemorrhages include overlooked vaginal tears and hematoma areas. Especially in prolonged labour, vacuum intervened deliveries and head pelvis incompatibility are more common. Infection of the repaired episiotomy area and opening of the wound may also reveal a bleeding picture. According to the reason, surgical correction should be made at the appropriate time.
In the adhesion anomalies of the placenta, when the placenta is left inside and the uterus is closed, severe bleeding may occur and hysterectomy may be required while the placenta is expected to resorb spontaneously or with the help of methotrexate.
Myomas, especially those that are submucosal or large myomas that increase the effect of stretching, can be effective in late bleeding. Anomalies in the veins and arteries can also occur in mole pregnancies, previous abortion and cesarean history, and cervical cancer.
Hematomas caused by damage to the pelvic vessels during cesarean section and removal of the repaired cesarean section with infection may also be the cause of bleeding. The first condition often requires surgical repair. However, cesarean section infection mostly responds well to antibiotic treatment.
Cases of choriocarcinoma may also occur with late bleeding.
In women with von Willewbrand disease (factor VIII deficiency), haemophilia carriers and factor XI deficiency, both early and late postpartum haemorrhages can be observed. Increased clotting tendency during pregnancy may protect the woman from early bleeding. However, late bleeding will occur more frequently in the reduction of coagulation factors. Since these bleeding can only occur with birth and major traumas, they can be diagnosed with postpartum haemorrhage.
The overall goal of treatment is primarily to quickly determine and correct the vital parameters of the woman. At the same time, medical or surgical treatment should be arranged by revealing the cause. At the time of application, women are generally better than women after early delivery. However, they can also apply with pain tables up to the shock table. 95% of women apply in the first month. In addition to clinical detailed evaluations, laboratory and imaging methods should be evaluated quickly. Treatment should also be planned rapidly, medically, or surgically, or in combination.