Failure to progress, or prolonged labour, is a relatively common occurrence during vaginal birth. According to one study, 8% of women have experienced a prolonged labour. Failure to progress is the primary indicator for an emergency caesarean delivery and delivery using instruments such as forceps or a vacuum.
Failure to progress, which may also be referred to as dystocia, occurs during the first two stages of labour. It is particularly dangerous to the mother and baby during the second stage of labour when the baby is moving through the birth canal.
The Stages of Labour
During a vaginal delivery, there are three stages of labour. These include early and active labour (stage 1), birth (stage 2), and delivery of placenta (stage 3).
During stage 1, the mother begins to feel regular contractions. This causes the cervix to dilate (open) and soften, shorten, and thin (effacement). When the cervix dilates and becomes effaced, the baby is able to move into the birth canal.
Stage 1 is the longest of the stages and is divided into two parts: early labour (latent phase) and active labour. In early labour, the mother will feel mild, irregular contractions. The length of early labour is unpredictable but may last between hours and days for nulliparous women (first-time mothers).
In active labour, the cervix will dilate from 6 centimetres (cm) to 10 cm. The contractions will become stronger, closer together and regular. At this point, the medical team may administer an epidural. Active labour typically lasts between 4 and 8 hours — or longer.
The last part of active labour is referred to as transition. Contractions will come close together and may last for as long as 60 to 90 seconds. At this point, the mother may feel the urge to push and will feel pressure in her lower back and rectum.
Stage 2 of labour will then commence. It may last anywhere from a few minutes to a few hours or longer. During this stage, the mother will be asked to bear down or push during each contraction.
In stage 2, the baby is moving through the birth canal. After the fetal head is delivered, the rest of their body will follow shortly. Once the baby is born, their airway will be cleared (if necessary), and their umbilical cord will be cut.
Stage 3 of labour lasts from 5 minutes up to an hour. The mother will continue to have mild contractions and will be asked to push one more time to deliver the placenta. After the placenta has been delivered, the uterus will continue to contract so that it can return to its original size.
Why Labour May Fail to Process
During the first two active phases of labour, there may be a lack of progression or even a complete cessation of labour. This is known as failure to progress (FTP).
Before labour begins, the cervix may not dilate or become effaced. If this occurs, then there is an FTP during the first stage of labour.
Once the second stage of labour begins, the baby should move down the birth canal at a certain pace — not too fast (which can cause vaginal tearing) or too slow (which may lead to FTP). There are a number of potential causes of FTP, including (1) uterine contractions that are too weak or too infrequent; (2) the baby is not in the right position or placement (malpresentation, such as breech birth); or (3) the baby cannot fit through the mother’s pelvis or its shoulders get stuck (shoulder dystocia). In some cases, the cause of FTP is unknown.
There are certain risk factors for FTP. These include:
- Starting labour with medications such as oxytocin or Pitocin
- The use of an epidural
- Premature rupture of membranes, which occurs when the mother’s water (amniotic fluid sac) breaks before labour starts
- Problems with the fluid sac around the fetus
- Prior FTP in a previous childbirth
- Fertility treatments
- A large baby for gestational age
If a mother is showing signs of failure to progress, then her obstetrician-gynaecologist can treat the issue in several ways.
Treatment for Failure to Progress
Throughout labour, the mother’s progress should be monitored. This may include using a monitor to determine the number of contractions, the spacing between contractions, and the length and power of the contractions. If there is a failure to progress, particularly in the second stage of labour, then the obstetrical team must intervene to prevent injury to the mother and baby.
If labour is not progressing, then an obstetrician can take measures to start to speed it up. According to the American College of Obstetricians and Gynecologists (ACOG), this may include techniques such as rupturing the membranes (breaking the water or amniotomy) or giving the mother oxytocin to make the uterus contract. If the FTP continues, then a doctor may use a vacuum or forceps to assist the baby through the birth canal to be delivered or perform a cesarean delivery (c-section).
Potential Complications of Failure to Progress
If labour is allowed to continue for an extended period of time with our progress, then the mother and baby may both be injured. For mothers, postpartum haemorrhage may occur after an unduly prolonged labour. Depending on the severity of the haemorrhaging, a hysterectomy (surgical removal of the uterus) may be performed. A hysterectomy will leave the mother unable to bear children in the future, and will also trigger premature menopause.
For babies, if labour progresses for an extended period of time — particularly in the second stage — they may decompensate. In a normal birth, a full-term, healthy baby has sufficient reserves to withstand the rigours of childbirth. If labour is prolonged, then the waves of contractions combined with the mechanical forces of the mother’s pelvis on the baby’s head may cause injury. The baby’s reserves will be depleted, and the baby may suffer a neurological injury or even death.