Postpartum haemorrhage (PPH) is still ranked among the top

three major causes of maternal death globally (WHO 2007).

Although the majority (99%) of deaths reported occur in

developing countries, the risk of PPH should not be

underestimated for any birth, nor should the potential for the

third stage of labour to be the most dangerous stage of

labour be underestimated (McDonald et al 2004, WHO

2007).

Chapter 29 :Physiology and management of third stage of

labour

Maternal mortality rates in high resource countries are

relatively low when compared to low resource countries,

however, maternal morbidity is similar in significance

. To facilitate a safe and healthy outcome for the mother and

her baby, antenatal health as well as intrapartum preparation

and postnatal skill, diligence and expertise of the midwife are

crucial factors. Research evidence is clearer for some

aspects of third stage management than others.

Chapter 29 :Physiology and management of third stage of

labour

Physiological processes

The third stage is defined as the period from the birth of the

baby to complete expulsion of the placenta and

membranes, involving the separation, descent and

expulsion of the placenta and membranes and control of

haemorrhage from the placenta.

Physiological processes

During the third stage, separation and expulsion of the

placenta and membranes occur as the result of mechanical

and haemostatic factors. The time at which the placenta

actually separates from the uterine wall varies. It may shear

off during the final expulsive contractions accompanying

the birth of the baby or remain adherent for some

considerable time. The third stage usually lasts between 5

and 15 min, but any period up to 1 hr may be considered to

be within normal limits.

Separation and descent of the placenta

Mechanical factors

The unique characteristic of uterine muscle lies in its power of retraction.

During the second stage of labour, the uterine cavity progressively

empties, enabling the retraction process to accelerate.

The vessels during this process become tense and congested. With the

next contraction the distended veins burst and a small amount of blood

seeps in between the thin septa of the spongy layer and the placental

surface, stripping it from its attachment .

This process of separation (first described by Schultze) is

associated with more complete shearing of both placenta and

membranes and less fluid blood loss (Fig. 29.3A).

The mechanism of placental separation. (A) Uterine wall is partially retracted, but not sufficiently to cause placental separation. (B) Further contraction and retraction thicken the uterine wall, reduce the placental site and aid placental separation. (C) Complete separation and formation of the retroplacental clot. Note: The thin lower segment has collapsed like a concertina following the birth of the baby.

Expulsion of the placenta. (A) Schultze method. (B) Matthews Duncan method.

Haemostasis

The normal volume of blood flow through the placental site is 500–800

mL/min. At placental separation, this has to be arrested within seconds,

as otherwise serious haemorrhage will occur. three factors within the

normal physiological processes that control bleeding They are:

1.Retraction of the oblique uterine muscle fibres in the upper uterine

segment through which the tortuous blood vessels work as a ligature

action. absence of oblique fibres in the lower uterine segment that

explains the greatly increased blood loss usually accompanying

placental separation in placenta praevia.

2- The presence of vigorous uterine contraction following

separation this brings the so that further pressure is

exerted on the placental site.

3-The achievement of haemostasis – there is activation

of the coagulation and fibrinolytic systems during, and

immediately following, placental separation.

Management of the third stage

The midwife's care of the mother should be based on an understanding

of the normal physiological processes

Having woman's pregnancy and labour history.

Progress of the first and second stages of labour are likely to impact on

management of the third stage .

The midwife's actions to reduce the very real risks of haemorrhage,

infection, retained placenta and shock.

Understanding the factors that may influence the risk of haemorrhage

are discussed in more detail later.

Uterotonics or uterotonic agents

Some drugs e.g. Syntocinon, ergometrine and prostaglandins) that

stimulate the smooth muscle of the uterus to contract.

They may be administered with crowning of the baby's head, at the

time of birth of the anterior shoulder of the baby, after the birth of the

baby but prior to placental delivery or following the delivery of the

placenta.

primary importance is that the health professional (whether a

midwife, GP or obstetrician) providing clinical care and advice .

Active management

An active management policy usually includes the routine administration of a

uterotonic agent, either intravenously, intramuscularly or even orally. This is

undertaken in conjunction with clamping of the umbilical cord shortly after birth

of the baby and delivery of the placenta by the use of controlled cord traction.

In situations where women at higher risk for PPH a prophylactic infusion of

larger doses of uterotonics diluted in intravenous solutions may be

administered over several hours following the birth.

management most widely practised throughout the developed world. Like all

interventions performed, skill in assisting the delivery of the placenta and

membranes is extremely important.

Expectant or physiological management

In expectant management, routine administration of a uterotonic

drug is withheld, the umbilical cord is left unclamped until cord

pulsation has ceased or the mother requests it to be clamped, or

both, and the placenta is expelled by use of gravity and maternal

effort. With this approach, therapeutic uterotonic administration

would be administered either to stop bleeding once it has

occurred or to maintain the uterus in a contracted state when

there are indications that excessive bleeding is likely to occur.

Intravenous ergometrine 0.25 mg This drug acts within 45 s;

therefore it is particularly useful in securing a rapid contraction

where hypotonic uterine action results in haemorrhage. If a

doctor is not present in such an emergency, a midwife may

give the injection.

ergometrine, is more often used to treat a PPH rather than as

a prophylactic drug.

Combined ergometrine and oxytocin (a commonly used brand is

Syntometrine) A 1 mL ampoule contains 5 IU of oxytocin and 0.5 mg

ergometrine and is administered by i.m. injection. The oxytocin acts

within 2½ min, and the ergometrine within 6–7 min (Fig. 29.5). Their

combined action results in a rapid uterine contraction enhanced by a

stronger, more sustained contraction lasting several hours. It is usually

administered as the anterior shoulder of the baby is born, thus

stimulating good uterine action at the beginning of the third stage. The

use of combined ergometrine/oxytocin or any ergometrine-based drug

is associated with side-effects such as elevation of the blood pressure

and vomiting (McDonald et al 2004).

Caution

No more than 2 doses of ergometrine 0.5 mg should be given as it can

cause headache, nausea and an increase in blood pressure and it is

normally contraindicated where there is a history of hypertensive or

cardiac disease Oxytocin is a synthetic form of the natural oxytocin

produced in the posterior pituitary, and is safe to use in a wider context

than combined ergometrine/oxytocin agents.

It can be administered as an intravenous and or intramuscular

injection. However, an intravenous bolus of oxytocin can cause

profound, fatal hypotension, especially in the presence of

cardiovascular compromise. The recommendation is that ‘when given

as an intravenous bolus the drug should be given slowly in a dose of

not more than 5 IU’.

Prostaglandins

In more recent years, a great deal of research time and investment has

been invested in seeking alternate ways of implementing strategies to

reduce the risk of PPH. Misoprostol (a prostaglandin E1 analogue) was

first used to treat gastric ulcers. It is cheap, not prone to loss of potency,

does not need to be sterile or refrigerated and can be administered

vaginally, orally or rectally negating the need for syringes.

The difference in the incidence of PPH between the women given 600

mg of misoprostol orally and the women who received other uterotonic

agents was 3.6% versus 2.7%. This translated to a >20% difference,

which was the tolerance level chosen beyond which it was believed

misoprostol was not as effective prescribed and administered uterotonic

globally.

Misoprostol was also found to have unpleasant side-effects, such as

severe shivering and higher temperature, both of which were transient but

unacceptable to some women.

Even though the recommendation was that misoprostol should not replace

other uterotonics in settings where they are available, the authors suggest

that it may be useful in circumstances where nothing else is available. The

transient side-effects associated with misoprostol may not be any more

debilitating than the nausea, vomiting (Ng et al 2007) and hypertensive

episodes experienced by some women receiving Syntometrine, which

remains the most commonly prescribed and administered uterotonic

globally.

Clamping of the umbilical cord

This may have been carried out during birth of the baby if

the cord was tightly around the neck. However, opinions

vary as to the most beneficial time for clamping the cord

during the third stage of labour.

Early clamping is normally applied in the first 1–3 min

immediately after birth, regardless of whether the cord

pulsation has ceased.

It has been suggested that this practice may have the following effects:•It may reduce the volume of blood returning to the fetus by as much as 75–125 mL, especially if clamping occurs within the first minute.•It may interrupt function of the placenta in maintaining O2 levels.•It may result in lower neonatal bilirubin levels, although the effect on the incidence of clinical jaundice is unclear.

•It may increase the likelihood of fetomaternal transfusion as a larger volume of blood remains in the placenta.

advantages of late clamping include:

•The route to the low resistance placental circulation remains patent,

This may be critical when the baby is preterm or asphyxiated, and the

difficulties in initiating respiration or accompanying circulatory

adaptation (Dunn 1985).

• The transfusion of the full allowance of placental blood to the

newborn. This may constitute as much as 40% of the circulating

volume depending on when the cord is clamped

Early cord clamping, which is usually part of active management, is in

general regarded as clamping of the umbilical cord within 30s of the birth

of the baby. Late cord clamping, a physiological approach, involves

clamping of the umbilical cord when cord pulsation has ceased.

early and late cord clamping vary and again, in practice, unavoidable

factors (e.g. if the cord is around the neck, the number of clinicians in the

room, the need for active resuscitation of the infant) can make it difficult to

adhere to a particular policy (McDonald 1996).

Debate continues over the effect of the extra 90–100 mL of blood

received by the baby when late cord clamping is practised (Mercer 2006).

Recent evidence suggests that the effects of early versus late cord

clamping may be different for pre-term and term infants (Rabe et al 2004).

Timing of cord clamping appears to be less of an issue in term infants.

Delivery of the placenta and membranes

Controlled cord traction (CCT). This manoeuvre is believed to reduce blood

loss, shorten the third stage of labour and therefore minimize the time during

which the mother is at risk from haemorrhage. It is designed to enhance the

normal physiological process.

If CCT is to be used, there are several checks to be made before proceeding:

• that a uterotonic drug has been administered

• that it has been given time to act

• that the uterus is well contracted

• that counter-traction is applied

• that signs of placental separation and descent are present.

When CCT is the preferred method of management, the following sequence of

actions is usually undertaken.

Some resistance may be felt but it is important to apply steady tension by

pulling the cord firmly and maintaining the pressure.

Jerky movements and force should be avoided.

A gentle upward and downward movement or twisting action will help to coax

out the membranes and increase the chances of delivering them intact.

Artery forceps may be applied to gradually ease the membranes out of the

vagina. This process should not be hurried; great care should be taken to avoid

tearing the membranes.

Evidence for active versus expectant management

It is strongly suggests that the prophylactic administration of a uterotonic

significantly reduces the risk of PPH, results in a lower mean blood loss,

fewer blood transfusions are required and there is a reduced need for

therapeutic uterotonics.

Taking all the best available evidence into consideration, a systematic

review of the literature by Prendiville et al (2002) recommended that all

women who birth in circumstances where this option is available should

be encouraged to do so.

Position of the woman

The effect of the position adopted by the woman at the time of placental

delivery is still largely unclear. It may vary according to the mother's

personal preference

Adoption of a dorsal position allows easy palpation of the uterine

fundus.

Upright, kneeling and all-fours positions may enhance the effect of

gravity and increase intra-abdominal pressure, which may in turn hurry

the placental delivery process.

The squatting position has been reported to increase visible blood loss

AsepsisThe need for asepsis is even greater now than in the preceding stages of labour .This may be required for a variety of conditions:•when the mother's blood group is Rhesus negative or if Rhesus type is unknown•when atypical maternal antibodies have been found during an antenatal screening test•where a haemoglobinopathy is suspected (e.g. sickle cell disease).

The sample should be taken as soon as possible from the fetal surface of the placenta where the blood vessels are congested and easily visible. These may include the baby's blood group, Rhesus type, haemoglobin estimation, serum bilirubin level, Coombs' test or electrophoresis.

Completion of the third stage

Once the placenta is delivered, the midwife must first check that the uterus

is well contracted and fresh blood loss is minimal.

Careful inspection of the perineum and lower vagina is important. A strong

light is directed onto the perineum in order to assess trauma accurately

prior to instigating repair.

Note. It should also be remembered that any amount of blood loss that

causes a physical deterioration such as feeling faint, sudden onset of

tachycardia, drop in blood pressure should be immediately investigated.

Examination of placenta and membranes

inspection must be carried out in order to make sure that no part of the

placenta or membranes has been retained. The membranes are the

most difficult to examine as they become torn during delivery and may

be ragged. Every attempt should be made to piece them together to give

an overall picture of completeness.

both placental surfaces examined in a good light. Any clots on the

maternal surface need to be removed and kept for measuring.

Immediate care

care for at least 1 hr after birth is very important,

Early physiological observations including ensuring a well contracted

uterus, assessment of vaginal blood loss and a gentle inspection of the

genital tract to inspect for trauma should be undertaken (NICE 2006).

The woman should be encouraged to pass urine because a full bladder

may impede uterine contraction.

Uterine contraction and blood loss should be checked on several

occasions during this first hour. Once basic procedures to ensure the

woman's and baby's safety and comfort have been completed, there is no

evidence to suggest that restriction of food or fluids is necessary.

Encourage breast feeding after delivery.

RecordsA complete and accurate account of the labour, including the documentation of all drugs, physical examination and observations, is the midwife's responsibility. This should also include details of examination of the placenta, membranes and cord with attention drawn to any abnormalities. The volume of blood loss is particularly important. Signatures are therefore essential, with co-signatories where necessary.

The completed records are a vital communication link between the midwife responsible for the birth and other caregivers, particularly those who take over care and provide ongoing community support services once the woman returns home.It is usually the midwife who completes the birth notification form. Timely notification and referral may prevent delay in a woman receiving appropriate assistance should she need it.

Transfer from the birth room

The midwife is responsible for seeing that all observations are made

and recorded prior to transfer of mother and baby to the postnatal

ward or before the midwife leaves the home following the birth.

The postnatal ward midwife should verify these details prior to

transfer of mother and baby. Following a domiciliary birth, the midwife

should leave details of a telephone number where she may be

contacted should the parents feel any cause for concern.

Complications of the third stage of labour

Postpartum haemorrhage

Primary postpartum haemorrhage is defined as excessive

bleeding from the genital tract at any time following the baby's

birth up to 24 hrs following the birth (WHO 2000).

A significant number of the deaths recorded were due to PPH.

The midwife is often the first and may be the only professional

person present when a haemorrhage occurs,

Primary postpartum haemorrhage

Fluid loss is extremely difficult to measure if the measured loss

reaches 500 mL, it must be treated as a PPH, irrespective of

maternal condition.

There are several reasons why a PPH may occur, including

atonic uterusretained placenta,trauma and blood coagulation disorder.

Atonic uterusThis is a failure of the myometrium at the placental site to contract and retract and to compress torn blood vessels and control blood loss by a living ligature action. Causes of atonic uterine action• Incomplete separation of the placenta• Retained cotyledon, placental fragment or membranes• Precipitate labour• Prolonged labour resulting in uterine inertia• Polyhydramnios multiple pregnancy• Placenta praevia• Placental abruption• General anaesthesia• A full bladder

Fibroids (fibromyomata)

Anaemia

•Previous history of postpartum haemorrhage or

retained placenta

•High parity resulting in uterine scar tissue

•Presence of fibroids

•Maternal anaemia

•Multiple pregnancy.

Signs of PPHThese may be obvious such as:• visible bleeding• maternal collapse.However, more subtle signs may present, such as:• pallor• rising pulse rate• falling blood pressure• altered level of consciousness; the mother may become restless or drowsy• an enlarged uterus as it fills with blood or blood clot; it feels ‘boggy’ on palpation (i.e. soft and distended and lacking tone); there may be little or no visible loss of blood.

Prophylaxis

By using the above list, it is possible for the midwife to apply some preventive

screening in an attempt to identify women who may be at greater risk and to

recognize causative factors. During the antenatal period a thorough and accurate

history of previous obstetric experiences will identify risk factors such as previous

PPH or precipitate labour. Arrangements can then, after careful explanation and in

full consultation with the woman, be made for birth to take place in a unit where

facilities for dealing with emergencies are available.

During labour, good management practices during the first and second stages are

important to prevent prolonged labour and ketoacidosis. A mother should not enter

the second or third stage with a full bladder. Prophylactic administration of a

uterotonic agent is recommended for the third stage, by either intramuscular injection

or intravenous infusion. Two units of cross-matched blood should be kept available

for any woman known to have a placenta praevia or is known to have pre-disposing

risk factors for PPH.

Treatment of PPH1 Call for medical aid.2 Stop the bleeding – rub up a contraction – give a uterotonic – empty the uterus.3Resuscitate the mother4Give a uterotonic to sustain the contraction5Empty the uterus

Secondary postpartum haemorrhage

Secondary postpartum haemorrhage is any abnormal or excessive

bleeding from the genital tract occurring between 24 hrs and 12

weeks postnatally. It is most likely to occur between 10 and 14 days

after birth. Bleeding is usually due to retention of a fragment of the

placenta or membranes, or the presence of a large uterine blood

clot., the lochia is heavier than normal and will have changed from a

serous pink or brownish loss to a bright red blood loss..

Subinvolution, pyrexia and tachycardia are usually present. As this is

an event that is most likely to occur at home, women should be

alerted to the possible signs of secondary PPH prior to discharge

from midwifery care.

Management

The following steps should be taken:

• call a doctor

• reassure the woman and her support person(s)

• rub up a contraction by massaging the uterus if it is still

palpable

• express any clots

• encourage the mother to empty her bladder

• give a uterotonic drug such as ergometrine maleate by the

intravenous or intramuscular route

• keep all pads and linen to assess the volume of blood lost

• if bleeding persists, OR is needed

Haematoma formationThis may be obvious at such sites as the perineum or lower vagina, but it is more difficult to diagnose if it occurs into the broad ligament or vault of the vagina. A large volume of blood may collect insidiously (up to 1 L).

Care after a postpartum haemorrhageWhatever the cause of the haemorrhage, the woman will need the continued support of her midwife until she regains her confidence. Her partner may also be fearful of a recurrence and need much reassurance. If the mother is breast-feeding, lactation may be impaired but this will only be temporary and she should be encouraged to persevere. The midwife is often the first and may be the only professional person present when a haemorrhage occurs, so her prompt, competent action will be crucial in controlling blood loss and reducing the risk of maternal morbidity or even mortality.