Labour, Birth & Pain Relief
Signs That Labour Has Begun
Labour is the process by which the baby moves from the uterus into the outside world. It is triggered by hormonal changes that usually occur around 40 weeks of pregnancy. The main signs that labour has started are a show (the discharge of the mucus plug from the cervix), a rupture of the membranes (waters breaking), and the onset of regular, painful contractions that increase in frequency and strength over time.
Not all signs appear together or in the same order. Some women experience their waters breaking before contractions begin; for others, contractions start first. A show may occur up to 72 hours before labour becomes established. Midwives advise timing contractions: once they are occurring every five minutes, lasting around 60 seconds and have continued for at least an hour, it is usually time to contact the maternity unit.
The three main signs of labour are: a show (loss of the mucus plug), rupture of the membranes (waters breaking), and regular, strengthening contractions. All three should be mentioned in exam answers asking for signs of labour.
The Three Stages of Labour
Labour is divided into three distinct stages. The first stage is the longest and involves the cervix gradually dilating to 10 centimetres. This stage can last from a few hours to over 24 hours, particularly in a first labour. It is further divided into the latent phase (0–4 cm, often managed at home) and the active phase (4–10 cm, usually in hospital). Contractions become longer, stronger and closer together as the cervix opens fully.
The second stage begins when the cervix is fully dilated and ends with the birth of the baby. The mother actively pushes with each contraction to move the baby down the birth canal. This stage typically lasts from minutes up to about two hours. The baby's head usually appears first, a moment called crowning. The third stage involves delivery of the placenta, usually within 30 minutes of the birth; it may be managed actively (an injection of oxytocin speeds placental separation) or allowed to happen naturally.
A natural (vaginal) birth is where the baby is born through the birth canal without surgical intervention. If labour stalls or the baby shows signs of distress, an assisted delivery may be needed. Forceps are smooth metal instruments shaped like large spoons that are placed around the baby's head to guide it out during a contraction; they may leave temporary marks on the baby's face. A ventouse (vacuum extraction) uses a soft cup attached to the baby's head by suction to help guide the baby out; it is less likely to cause maternal tearing but may leave a temporary swelling on the baby's head called a chignon.
A caesarean section (C-section) is a surgical operation in which the baby is delivered through an incision in the mother's abdomen and uterus. It may be planned in advance (elective) if there is a known risk, such as placenta praevia or a breech presentation, or performed as an emergency if complications arise during labour. Recovery from a caesarean takes longer than from a vaginal birth, and the mother will usually remain in hospital for two to three days. Around one in four babies born in the UK is delivered by caesarean section.
Methods of Pain Relief
Pain relief in labour ranges from simple natural methods to medical interventions. gas and air (Entonox) is the most widely used form of pain relief in UK maternity units. It is inhaled through a mouthpiece at the start of each contraction and takes effect within seconds. Advantages include that it is self-administered, does not slow labour and wears off quickly; disadvantages are that it may cause dizziness or nausea and only takes the edge off pain rather than eliminating it.
Pethidine is an opioid drug given by injection into the thigh or buttock. It takes 20 minutes to work and lasts three to four hours. Advantages include that it allows the mother to rest between contractions; disadvantages are that it can cross the placenta and cause drowsiness and breathing difficulties in the newborn, and it may cause nausea in the mother. An epidural involves an anaesthetist inserting a fine tube into the epidural space in the lower back; drugs (usually a mix of local anaesthetic and opioid) are delivered continuously or on demand. An epidural provides the most effective pain relief but can slow labour, limit mobility, increase the likelihood of an assisted delivery and cause a drop in blood pressure. A TENS (Transcutaneous Electrical Nerve Stimulation) machine uses small electrical pulses delivered via pads on the back to interrupt pain signals; it is safe, drug-free and controlled by the mother, but is most effective only in early labour.
Natural methods of pain relief include water (a birthing pool can soothe pain and allow mobility), breathing and relaxation techniques, massage, and hypnobirthing. These carry no medical risk to mother or baby and can be used alongside other methods; however, they may not be sufficient for more intense labour pain.
Students often muddle forceps and ventouse. Remember: forceps are metal instruments that cup around the head (think of large salad servers), while a ventouse uses suction. A ventouse is less likely to tear the perineum but cannot be used if the baby is very premature or in certain positions. Forceps require a larger episiotomy but can rotate the baby's head if it is in the wrong position. In the exam, name the method correctly and state one specific feature — do not describe them interchangeably.