Postpartum haemorrhage (PPH) is when there is bleeding of at least 500ml of blood after vaginal delivery or 1000ml after C-section. This is specifically referred to as primary PPH. Secondary PPH refers to vaginal bleeds of 500ml or more up until 12 weeks postpartum. It is a huge contributing factor to maternal morbidity and mortality and is considered a medical emergency.
🔢 Classification
We can classify PPH based on the time when it occurs as well as the amount of blood loss:
Temporal classification:
- Primary PPH - loss of at least 500ml of blood (vaginally) within 24 hours of delivery of the baby.
- Secondary PPH - loss of at least 500ml of blood (vaginally) from 24 hours - 12 weeks of delivery of the baby.
Quantitative classification
- Minor PPH - <1000ml of blood lost.
- Major PPH - >1000ml of blood lost. It can be sub classified as moderate (1000-2000ml) or severe (>2000ml).
Pathophysiology
There are 3 (some may consider 4) stages of labour:
First stage:
This is from the onset of contractions until the cervix is fully dilated to 10cm. The cervix undergoes effacement (ripening) where it becomes shorter until it essentially is absent at the junction of the vaginal canal and the uterus. The mucus plug which blocks the cervix during pregnancy becomes loose and falls away.
We can break down the first stage of labour into 3 sub-stages:
- Latent phase - this is when the cervix dilates from 0-3cm at a rate of approximately 0.5cm per hour (but this actually can take much longer as in days to weeks even). During the latent phase, uterine contractions are irregular.
- Active phase - dilation of the cervix from 3-7 cm at a rate of 1cm per hour. Contractions are more regular throughout this stage.
- Transition phase - dilation from 7-10cm at a rate of 1cm per hour. The contractions are regular but stronger throughout this phase.
Second stage:
This stage is from full dilatation of the cervix (10cm) to delivery of the baby.
There are 3 P’s that the second stage is dependent on:
- Power - uterine tone.
- Passenger - the baby and its features. Namely:
- Size - especially the head of the baby as this is the largest part.
- Attitude - the posture of the foetus. We refer to the rounding of the back, the flexion of the limbs and the posture of the head. The head should be flexed and not extended (as in a stargazing posture). We can refer to the attitude as vertex, military, brow and face.
- Lie - longitudinal, oblique or transverse.
- Presentation - cephalic (head first), shoulder, breech (legs first). Breech can be complete (cannonball position), frank breech (hips flexed and knees extended, or footling breech (foot hanging out of the cervix). Footling breech is the most dangerous type.
- Passage - shape and size of the bony pelvis as well as the soft tissue structures. The bladder and rectum are also to be considered here.
Third stage:
From delivery of the foetus to delivery of the placenta. This is the phase where postpartum haemorrhage takes place.
In this phase we may have physiological management in which the placenta is delivered naturally by the mother. We may also have active management where placental delivery is assisted by the doctor. NICE recommends advising women on the lower risk of PPH associated with active management. Active management involves 3 components - uterotonics, early cord clamping and controlled cord traction when delivering the placenta.
Some consider a fourth stage to be the first 2 hours after birth. This is also a crucial period for PPH to develop.
The aetiology of primary PPH is attributable to the 4 T’s:
- Tone - uterine atony specifically. This refers to the failure of the uterus to contract as a result of a loss of tone in uterine muscle. A lack of uterine contraction means that the placental blood vessels do not constrict and therefore haemorrhage occurs. It happens in approximately 2% of all labours, however, it does not always lead to PPH. Factors that may lead to uterine atony:
- Maternal age
- BMI >35
- Asian ethnicity
- Uterine distension - due to multiple pregnancy, polyhydramnios, macrosomic baby.
- Labour - a prolonged labour as well as induction of labour is more likely to lead to uterine atony too.
- Placental issues - placenta praevia, placental abruption.
- Trauma - for example with C-section, instrumental delivery, episiotomy.
- Tissue - retained products of conception leads to continuous bleeding.
- Thrombin - coagulopathies such as von Willebrand’s disease, haemophilia, immune thrombocytopenia, DIC, HELLP syndrome.
Secondary PPH is usually due to retained products of conception (RPOC) or infection (specifically endometritis). Some rarer causes may be trophoblastic disease as well as issues with involution of the placental area within the uterus leading to the spiral arteries sloughing off.
⚠️ Risk factors
- History of PPH
- Prolonged labour/induction of labour
- Pre-eclampsia
- Maternal age >40
- Polyhydramnios
- Emergency C-section
- BMI >35
- Placental issues - placenta praevia, placenta accreta, retained placenta
- Multiple pregnancy
- Obesity
- Macrosomic baby
- Instrumental delivery
- Episiotomy
- General anaesthesia
😷 Presentation
The predominant feature of PPH is vaginal bleeding that is persistent and excessive after delivery.
Other symptoms may include symptoms of hypovolaemic shock such as: dizziness, blurred vision, syncope, tachycardia, pallor.
🔍 Investigations
The investigations for PPH are more aligned with rectifying the issue of haemorrhage and haemodynamic instability if present (A-E assessment). If it is a secondary PPH, it is more aligned to identifying the cause.
Primary PPH investigations:
- Cross match 4 units of blood
- FBC, U&Es LFTs, coagulation profile
- We can also opt to perform a speculum examination and examination of placenta. It is important to ensure the placenta is complete.
Secondary PPH investigations:
- Speculum examination
- Ultrasound examination - looking for a retained placenta.
- CRP coagulation profile, blood cultures, U&Es
- Endovervical/high vaginal swab - assessing for any infection present.
🧰 Management
PPH occurs in the third stage of labour. The recognition of PPH requires urgent escalation to obstetric-led care.
- A-E approach with frequent observations if resuscitation is required.
- Insert 2 x 14 gauge peripheral cannulae.
- Keep the woman flat.
- Perform bloods such as group and cross match 4 units, FBC, U&Es, coagulation profile.
- Initiate warmed IV fluid infusion.
- Cross matched blood may be transfused. Fresh frozen plasma may be useful in instances of clotting abnormalities
- Supplementary oxygen - regardless of oxygen saturation.
🚨 If need be, activate the major haemorrhage protocol.
The definitive management of PPH involves stopping the bleeding. This can be achieved through 3 categories of options, depending on what the cause of the bleeding is and the severity/urgency. These 3 categories include mechanical, medical and surgical means of management.
Mechanical management:
- Bimanual compression - inserting one hand into the vagina and then forming a fist to compress the uterus, while the other hand compresses the posterior uterus via the abdomen.
- Catheterisation - to empty the bladder as distension of the bladder can prevent uterine contractions.
Medical management:
- 🥇 Oxytocin - given as a slow IV bolus (over 5 minutes usually) initially, followed by an IV infusion of 40 units within 500mls.
- 🥇 Ergometrine - given as a slow IV injection or as an IM injection. It is contraindicated in hypertensive patients, eclampsia and vascular disease. It increases the amplitude and frequency of uterine contractions. Combined with oxytocin it is more effective than oxytocin alone.
- Carboprost - given as an IM injection. Contrandicated in asthmatic and cardiac disease patients. A prostaglandin analogue that stimulates uterine contractions.
- Misoprostol - given sublingually. Another prostaglandin analogue that stimulates uterine contractions.
- Tranexamic acid - an antifibrinolytic that can aid clotting and preventing further bleeding.
Surgical management:
- 🥇 Intrauterine balloon tamponade - a balloon that is inserted into the uterus and inflated to provide a tamponade effect through compression. Of the surgical measures it is the first-line option.
- B-lynch suture - this is a type of suture that is used to compress the uterus.
- Uterine artery ligation or internal iliac artery ligation.
- Hysterectomy - this is more of a last-line option that is reserved as a life-saving procedure.
For women offered a combination of oxytocin and ergometrine they should be offered an antiemetic and advised on the emesis that it is likely to cause
Management of secondary PPH:
Once again the initial management should be based on the woman’s haemodynamic status.
- Antibiotics - ampicillin + metronidazole. Clindamycin may be used in place of ampicillin if allergic.
- Oyxtocin and other uterotonic medications ay be used also.
- Surgery - surgical evaluation of the uterine cavity looking for RPOC, irrespective of the findings on ultrasound. In the post-partum period the uterus is softer and thinner and there should be caution taken to ensure one does not perforate the uterus.