The third stage of labour
In this article:
- A Physiological, or natural, third stage
- An active, or managed, third stage
- Which type of third stage should you choose?
- Timing of umbilical Cord clamping
- Excessive bleeding during the third stage
- What if the placenta fails to deliver?
- Main points
- Further information
Labour is divided into 3 distinct parts. The first part starts when contractions are regular and strong and ends when the cervix (the neck of the uterus, or womb) is open to the point that it cannot be felt on examination. The second part of childbirth begins when the cervix is fully open and ends with the birth of the baby. Although labour is almost complete when the baby is born, it is not quite over because the placenta has to be delivered and any bleeding has to stop. The placenta, which develops alongside the baby during pregnancy, acts as a type of reservoir or interface where nutrients and oxygen from the mother’s blood pass to the growing baby. So the third stage of labour starts when the baby is born and ends with the expulsion (delivery) of the placenta and the control of any bleeding. The baby’s umbilical cord is usually clamped and cut during this stage. The third stage can last for just a few minutes to around 20.
You can choose between two main approaches to ‘managing’ the third stage of labour: physiological management and active management.
A Physiological, or natural, third stage
This is when the placenta is allowed to deliver without intervention from health professionals. Drugs are not given routinely and the midwife or doctor does not apply traction (pull) to the umbilical cord (which is attached to the placenta) to hasten delivery. The hormone oxytocin, released during and following birth, causes the uterus to contract. Because breastfeeding can increase the release of oxytocin, breastfeeding during a physiological third stage can help the placenta deliver. During the third stage, contractions cause the placenta to detach from the uterine wall. Sometimes the women may feel the need to bear down gently to aid the expulsion of the placenta, but this should be limited and only gentle. A physiological third stage may take longer to complete than an active third stage, but most are completed in 20 minutes. There is good research evidence to show that the amount of bleeding during a physiological third stage is greater than during an active third stage; however, for most women this is not a problem, and in many cases the blood loss is not serious. If the placenta fails to deliver or blood loss seems heavy, your midwife or doctor may advise that routine drugs should be given, these drugs are artificial versions of the natural hormone oxytocin, and they help the uterus to contract strongly.
An active, or managed, third stage
Active management of the third stage happens when drugs are administered routinely to reduce the length of the third stage. The drugs do this by increasing the strength of uterine contractions, which help detach the placenta from the uterine wall; this shortens the length of the third stage and reduces blood loss compared to a physiological third stage. An active third stage usually lasts 3 or 4 minutes. The drugs used during the third stage are given either into the woman’s vein (usually in her hand or arm) or into the muscle of her thigh or bottom; this is done following the baby’s birth.
Which type of third stage should you choose?
Most women are able to have a safe physiological third stage; however, some women may be more likely to bleed heavily at this time than others and therefore may be advised by their midwife or obstetrician that an active third stage would be best. Certain factors including giving birth to a large baby, having a long labour, having had several previous babies, being obese, or retaining a placenta make bleeding heavily during the third stage more likely.
Timing of umbilical Cord clamping
The baby’s umbilical cord is normally clamped and cut fairly soon following birth. The timing of cord clamping is important because blood continues to pass between the baby and the placenta following the birth if the cord is not cut – research evidence suggests that blood flow between the placenta and the baby can continue for several minutes after the baby is born. This continued passage of blood (sometimes called placental transfusion) can influence the baby’s blood volume immediately following birth, and this can influence iron stores for several months. Often during a physiological third stage the cord is not clamped and cut for several minutes, whereas during an active third stage it’s more common to clamp and cut the cord fairly soon after birth. Even with an active third stage, it is possible to leave the cord unclamped for a few minutes. Some maternity units have a policy about when cords should be clamped and cut, so you may want to ask your midwife about this.
Excessive bleeding during the third stage
If a woman is at increased risk from bleeding during the third stage, she may be advised that an active third stage is best. She may also be advised that she may benefit from an intravenous drip with the drug oxytocin in it to help stop bleeding if it starts. Most bleeding can be controlled with drugs, and it is very unlikely that any other intervention is needed. However, in very rare cases bleeding may not stop and surgery may be needed. This can happen if a tear has occurred, particularly to the cervix (neck of the womb, which is also very rare) or if the uterus will not contract. If the uterus will not contract and bleeding continues, a hysterectomy (removal of the uterus) is the only action that will stop bleeding, but this happens in only 0.1 to 0.3/1000 normal births (this figure is slightly higher for caesarean births).
What if the placenta fails to deliver?
A placenta is ‘retained’ if it fails to deliver within 30 minutes of the baby’s birth. Some factors increase the chance of a retained placenta – for example, if you have had a retained placenta before, if the first or second stage of labour is long, if you have a full bladder, if you have had a caesarean section before, if your baby is preterm or stillborn, or if you are over 30 years old. There are three main reasons why a placenta doesn’t deliver: (i) the placenta is trapped behind a tightly closed cervix (ii) contractions are not strong enough to detach the placenta from the uterine wall properly or (iii) the placenta is abnormally attached to the uterine wall.
More time may be allowed for the placenta to deliver if bleeding is minimal, but the chance of increased bleeding rises if the placenta is retained, so your midwife or doctor may suggest interventions to try and help the placenta deliver around this time.
These interventions are often all that is needed, but sometimes a woman may need to have her placenta removed in the operating theatre. In this case an epidural or spinal anaesthetic will most likely be offered as most retained placenta are removed vaginally by hand (manual removal of the placenta) and this can be quite uncomfortable. Antibiotics will be given, as infection risk is increased when a placenta is removed manually.
- The third stage of labour begins when the baby is born and ends with the delivery of the placenta. It can last from just a few minutes to around 20.
- You can choose to have either a physiological or an active third stage of labour.
- A physiological third stage is when the placenta is allowed to deliver without intervention from health professionals.
- Released during and following birth, the hormone oxytocin causes the uterus to contract, helping deliver the placenta.
- An active, or managed, third stage is when drugs are administered to reduce the length of the third stage. The drugs increase the strength of the contractions, which helps detach the placenta from the uterine wall.
- A physiological third stage can last longer than an active third stage, but most don’t last longer than 20 minutes.
- The amount of bleeding is also greater during a physiological stage than it is during an active third stage, but in many cases the amount of blood loss is not severe and most women are able to have a safe physiological third stage.
- There are some circumstances under which a midwife or doctor may recommend an active third stage over a physiological third stage. For instance, if they’ve given birth to a large baby, have had several previous babies, are obese, or have retained their placenta, then they are at a higher risk of heavier bleeding, and an active third stage is thought to be safer.
- Because blood continues to flow between the placenta and the baby for several minutes after birth, influencing the baby’s blood volume and iron stores for several months, the timing of the cord clamping and cutting is important. The cord tends to be cut sooner after birth in an active third stage than it is in a physiological third stage.
- Women at increased risk of heavy bleeding may be offered an intravenous oxytocin drip to help stop bleeding if it starts.
- In the rare case that bleeding cannot be controlled, such as if there has been a tear to the cervix, surgery may be required.
- If the placenta fails to deliver within 30 minutes of the birth, it is ‘retained’. Different interventions can help deliver the placenta, but sometimes it may need to be removed by hand, a procedure known as the manual removal of the placenta.
- Rarely, only a small portion of the placenta may be retained, causing abdominal pain, fever, increased bleeding, and vaginal discharge with an offensive smell. If you experience these symptoms, you should seek help from your GP or accident and emergency department.
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Farrar D, Airey R, Law G, Tuffnell D, Cattle B, Duley L (2011). Measuring placental transfusion for term births: weighing babies with cord intact. BJOG 118: 70-75.
Farrar D, Tuffnell D, Airey R, Duley L (2010). Care during the third stage of labour: A postal survey of UK midwives and obstetricians. BMC Pregnancy and Childbirth 10(1): 23.