Bleeding during delivery is common but usually minor, and well compensated for by the physiological changes of pregnancy. However, major haemorrhage is a significant cause of maternal morbidity and mortality throughout pregnancy. Life threatening haemorrhage occurs in around 6.7 per 1000 deliveries.
Bleeding in pregnancy can be categorized into 3 main categories:
Bleeding in early pregnancy - before 24 weeks gestation
Antepartum haemorrhage - after 24 weeks gestation
Early - <24 hours
Late - 24h - 6 weeks
The aetiology of the bleeding is different in each category.
Bleeding in early pregnancy:
Early postpartum haemorrhage:
Genital tract trauma
Adherent placenta (e.g. accreta)
Retained products of conception
Late postpartum haemorrhage
Retained products of conception
Rarely, other causes can lead to major haemorrhage e.g. splenic or hepatic haemorrhage in pre-eclampsia patients.
Many of the principles in management will be similar in each category, but there will also be some significant differences.
Massive Obstetric Haemorrhage
This is variably defined as:
Blood loss > 1500ml
Hb drop > 4g/dl
Transfusion requirements > 4 units PRBC
Some important aspects include:
Uterine blood flow in pregnancy is 700-900ml/min (12% of cardiac output) - exsanguination can be rapid.
Uterine bleeding can be hard to control
The beneficial physiological changes of pregnancy to cope with haemorrhage (increased plasma volume, increased stroke volume) can mask the signs usually associated with it
Blood loss can be hard to estimate because of the presence of amniotic fluid (and concealment) - volume replacement should usually be instigated early
Smaller patients will need lower thresholds as such blood loss will reflect a greater percentage of their circulating volume.
Much of the management is the same, regardless of the nature of the haemorrhage. There will of course be some variations in ante and postpartum haemorrhage.
An A to E assessment process will help provide a structured approach. This will include:
Get help early
15L NRB mask O2
Left lateral position if antenatal - can consider leg raise
Establish large bore access - x2 16g cannula
Cross match 6 units PRBC
Provide volume resuscitation
Activate massive haemorrhage protocol if suspicion of need
Crystalloid as temporising measure
PRBC as soon as possible - O negative or type specific
Warm all fluids
Consider these factors which will be related to the nature of bleeding.
Delivery of the foetus in major APH is likely to be needed
Specific surgical interventions may be need in PPH, including hysterectomy
There are number of uterotonic agents used for PPH
Avoid uterine relaxants in PPH
Tranexamic acid may play a role in major haemorrhage
This will be guided by the clinical scenario, including the condition of both the mother and foetus (if antepartum). In general, if there is cardiovascular compromise, general anaesthesia will likely be the method of choice, because of the potential disastrous effect of neuraxial blockade on sympathetic tone (coagulopathy may also develop rapidly in these patients). A stable induction will be essential. Ketamine and etomidate have pharmacologically advantageous profiles for this, but skilled use of propofol and thiopentone may still allow relative CVS stability.
Additional intraoperative factors include:
Establishing invasive BP monitoring
Employing cell-salvage (where time and facilities allow)
Minimising uterine relaxation by avoiding excessive volatile anaesthetic agent doses.
The important principles in massive obstetric haemorrhage are to maintain adequate intravascular volume and oxygen carrying capacity. Initial resuscitation with crystalloids can achieve the former, but RBC transfusion may be required, especially in massive haemorrhage. Thresholds and triggers have been hard to define due to the variation in speed of bleeding, and the subsequent challenges of clinical detection and biochemical detection. Even point of care testing of haemoglobin can be misleading in rapid haemorrhage. As such, guidance is to combine clinical and biochemical assessment to guide transfusion practice.
Many aspects of major haemorrhage in other contexts therefore also apply:
Group O negative blood if needing urgently
The use of ‘major haemorrhage packs’ for appropriate blood product ratios
Major haemorrhage is cover in more detail elsewhere.
As noted above, this is defined as bleeding in pregnancy at a gestation of greater than 24 weeks (i.e. once foetal viability has been reached). It complicates approximately 3% of pregnancies. There is a particular increase in perinatal morbidity and mortality, but also a risk to the mother. The causes, as noted above, include:
Placental abruption (about ⅓)
Placenta praevia (about ⅓)
Other causes e.g. uterine rupture, vasa praevia (about ⅓)
The rarer causes include; vaginal trauma, cervical inflammation, cervical cancer.
A to E assessment as with other critically ill patients, and will be similar to the general measures Specific points include:
Establish wide bore IV access (2 x 16g cannula)
Send bloods - FBC, Coagulation
Crossmatch blood - 6 units PRBC. Consider major haemorrhage protocols if indicated. Be aware of the potential for coagulopathy.
Foetal assessment will form an important part of the overall assessment and subsequent management plan. Assessment of foetal heart rate can provide information on whether there is foetal compromise and thus on the urgency of ongoing care.
This is where there is premature separation of the the placenta from the uterine wall. It can occur at any time in the pregnancy and may be partial or complete. Risk factors include:
Previous abruption (biggest risk)
Uterine distension e.g. polyhydramnios, multiple pregnancy
Abdominal trauma e.g. RTC, domestic violence
In many cases it will occur without warning in patients with no risk factors.
The presentation is one of abdominal pain +/- vaginal bleeding. The presentation may be divided into:
Revealed - bleeding occur PV (80%)
Concealed - no bleeding PV (20%)
The concealed form may be considered the most dangerous as the degree of blood loss can be easily underestimated. In the revealed form, blood will drain out the cervix. The volume of blood can still be totally unrelated to the total blood loss, but is more likely associated with a incomplete abruption.
The bleeding results in myometrial irritation and abdominal pain. This abdominal pain is usually continuous, but the bleeding can also trigger uterine contractions and the onset of labour. The uterus will often be tender, and can be described as feeling ‘woody’.
The clinical picture can be very variable, but important consideration include:
there may be significant hypovolemia resulting from this haemorrhage and the mother may be overtly shocked.
Some mothers may have no hypovolaemia.
The disruption of placental blood flow can again be variable, resulting in varying degrees of foetal hypoxia and distress, or even death.
The initial management should be the focused A to E assessment and resuscitation as described for general obstetric haemorrhage. Again, the wide variation in presentation means that there may be a range of subsequent management options.
If the abruption is minor, and the mother and foetus are unaffected, then the patient may be admitted for monitoring only. In the case of more significant abruption, then there may be a few scenarios, though the management options will be guided by the obstetric team. Treatment will primarily focus on maternal resuscitation and optimising care of the foetus, giving a few approaches:
Uncompromised foetus - may aim for normal vaginal delivery
Compromised foetus - emergency delivery by C-section
Foetus already dead - vaginal delivery unless other implications
Steroids may be given in cases where the foetus is still premature, and there may be efforts to delay delivery to allow optimal effect. Labour may be induced in some patients if it hasn’t been triggered e.g. amniotomy.
If the patient is labouring, epidural analgesia would likely be the analgesia option of choice. This will allow good analgesia as well as hopefully providing easy access to anaesthesia if urgent surgical input required. As in other cases of major obstetric, general anaesthesia may be the preferred technique in cases where there is maternal physiological disturbance (cardiovascular, coagulopathic).
Patients who have has placental abruption are at an increased risk of PPH. Large amounts of blood in the uterus may impair uterine contraction. Uterotonics should be used to help with appropriate uterine contraction and thus reduce haemorrhage.
This refers to the pathological condition when the placenta is inserted into the lower segment of the uterus (either wholly or partly). It is potential cause of both maternal and foetal morbidity and mortality and a cause of antepartum haemorrhage. A low lying placenta is a common finding in early pregnancy (approx. 5%), but in the majority of cases this resolves with ongoing development of the lower segment of the uterus. It is present in about 0.5% of pregnancies at term.
Minor - the placenta doesn’t cover the os but is in the lower segment
It is usually detected on routine ultrasound scan. As noted, this is not that uncommon at 20 weeks, but the placental position will not improve on follow up scanning.
Painless vaginal bleeding is the most common presentation of problems. This can often be brisk but brief in nature. In some cases in can be associated with some pain if there concomitant abruption. Although it is not associated with triggering labour in the same way as abruption, there is an increased risk of premature labour developing in the following days after a bleed (in about 25%). Sometimes a small ‘sentinel bleed’ may occur before a significant APH.
Problems occur with the normal mechanics of delivery because of the position of the placenta. As such it is common for there to be a high presenting part or abnormal lie of the foetus.
There is a high risk of patients with placenta praevia who have had a previous c-section of having placenta accreta. These patients should be managed as such.
Again, there can be a wide variety of clinical presentations, from stable but recognised placenta praevia, to significant APH. Factors that can influence decision making include:
These factors will be weighed by the MDT caring for the patient.
Stable placenta praevia Patients with grade 1 or 2 (minor) placenta praevia may be able to deliver vaginally. Patients with grade 3 or 3 (major) placenta praevia will likely need to deliver by C-section. This will aim to be performed at 38 weeks gestation. If there has been bleeding, or other risks are involved, then decisions for early delivery may be considered.
Patients with bleeding In mild bleeding with both maternal and foetal stability, it is often the case that a process of active observation will continue until 37 weeks gestation, to optimise foetal development.
In moderate or severe bleeding, and with signs of maternal or foetal compromise, it is likely that urgent delivery is required (which will generally be through cesarean section) alongside resuscitation of the mother.
Resuscitative and anaesthetic measures will mostly be the same as for other cases of major obstetric haemorrhage as previously outlined. Additional factors for consideration include:
Highly vascular lower segment can result in a greater intraoperative blood loss and a greater risk of PPH - appropriate use of uterotonics and post-operative monitoring is required.
Complex surgical cases (e.g. a more adherent placenta state) may outlast a single shot spinal - consideration of a CSE technique may be appropriate.
This is blood loss that occurs after delivery. As some degree of bleeding with any delivery is ‘normal’, the thresholds are defined as:
There are several causes of PPH, best remembered by the mnemonic “The 4 T’s”:
Tone This refers to uterine atony. Normally the myometrium will contract down after delivery, reducing blood flow through the uterine arteries. If this doesn’t occur, blood flow through these vessels can continue, leading to bleeding. It is responsible for around 80% of PPHs. Risk factors for uterine atony include:
Uterine distension - twins, multiple pregnancies
Uterine fatigue - prolonged labour
Obstruction - full bladder, fibroid
Medication - general anaesthetics, magnesium,
Trauma This refers to any trauma of the genital tract. This may be from the delivery, or iatrogenic:
Trauma from baby - perineal tear, vaginal, cervical
Cesarean section - bleeding from incision sites
Instrumentation - forceps, episiotomy
Tissue This refers to retained tissue with the placenta that allows bleeding to continue. This usually means the placenta, either wholly or fragments of it. In rare cases, a morbidly adherent placenta may be the cause e.g. placenta accreta.
Thrombin This refers to a physiological disturbance of haemostasis that is resulting in ongoing bleeding. Whilst less commonly a cause of PPH by themselves, they may complicate other causes. There are clearly many causes of this, but some are more common in obstetric practice:
Genetic e.g. Von Willebrand disease
The principles of management again follow those of obstetric haemorrhage already described. In addition, there are some more specific treatment considerations for the different causes of PPH, and hence the usefulness of “the 4 T’s” in helping to guide management.
Tone The management strategies can be consider in terms of medical and nonmedical interventions.
Medical interventions are primarily drugs that cause uterine contraction (uterotonics). These are discussed in more detail elsewhere, but usually consist of a stepwise approach:
Oxytocin 5 units (may be repeated)
Oxytocin infusion (40 units/500ml - 125ml/hr)
Carboprost 0.25mg (max 8 doses at min 15 mins intervals)
Misoprostol 800mcg sublingual
Uterotonics are recommended to be given electively in all patients to reduce the risk of PPH. It is also important to identify and minimise the impact of other medications that are potentially having a relaxing effect on the uterine tone (mentioned above). As an example, in a patient under general anaesthesia steps to reduce the relaxing effect of volatile anaesthetic agents are taken (using nitrous oxide, reducing MAC).
Nonmedical interventions are general procedures that aim to mechanically trigger uterine contraction, or reduce bleeding through their direct action. They are often considered as second line to medical management, but in cases of significant bleeding must clearly be deployed in parallel whilst medical therapy takes effect. This may be through compression e.g. intrauterine balloon, or other surgical interventions on the uterus:
Uterine massage - ‘Rubbing up a contraction’
Uterine artery ligation/embolisation
Uterine massage is an easy, routine steps undertaken to try and aid uterine contraction. Massage of the uterus can stimulate muscular contraction and can be done easily by midwifery staff early on in the management process. Similarly, urinary catheterisation is a rapid, simple procedure that can aid uterine contraction, as well as being part of monitoring. In general, further ‘surgical’ management will be to some degree dependent on the surgical expertise within the team that are present.
Bimanual compression refers to a more invasive procedure where the goal is to tamponade ongoing uterine bleeding with direct pressure.
Intrauterine balloon tamponade e.g. Bakri balloon, is recommended as the first line ‘surgical’ intervention. The balloon ‘tamponade test’ describes whether the inflation of the balloon is effective in controlling haemorrhage. If positive (i.e. it stops bleeding) it is reassuring that laparotomy is not required, whilst if it fails, progression to laparotomy is generally indicated. This video provides a nice overview of the balloon: https://www.youtube.com/watch?v=hRBtRZxf6Kk
Haemostatic suturing is often the next step in surgical management. This involves the use of a suture to generate general uterine compression and thus control bleeding. This is often done at laparotomy (although one technique does not require this) and so may be more useful in cases of PPH at cesarean section. This is a good video demonstrating a B-Lynch suture: https://www.youtube.com/watch?v=sskjFqJ17hk
Ligation or embolisation of uterine vessels may be another approach to gaining control of haemorrhage. This may be ligation at laparotomy, or embolisation by radiological methods. A staged approach has been described:
One uterine artery
Both uterine arteries
Low uterine arteries
One ovarian artery
Both ovarian arteries
Internal iliac artery ligation has also been described.
Hysterectomy may be required in some cases as a life saving procedure. Examples of when it may be more likely needed include cases of a morbidly adherent placenta or uterine rupture. Early decision making is often needed and the RCOG recommend 2 experienced clinicians being involved in the decision.
Trauma Trauma to the genital tract which results in bleeding clearly requires intervention to help gain haemostasis. This may entail transfer to theatre, with repair being dependent on the type of trauma present e.g. perineal repair.
Tissue Any retained tissue may be contributing to ongoing bleeding, so the goal of management here is around its removal. Again, this may well entail a transfer to theatre and anaesthesia to facilitate e.g. manual removal of placenta.
Thrombin Thrombin abnormalities (i.e. coagulopathies) are more likely to be a development of other causes of PPH, but then form part of a vicious circle. As such, the systematic approach to massive haemorrhage already described includes components to reduce this risk (maintaining normothermia, preventing acidosis, appropriate replacement of clotting factors and fibrinogen).
Some patients may be identifiable in advance as being at higher risk of bleeding due to coagulation abnormalities, and these risk factors should be mitigated where possible. Consideration should be given to electively giving 0.5-1g Tranexamic acid IV during cesarean section for patients who are at high risk of PPH to promote haemostasis. TXA should also be given to all woman with ongoing PPH.