Labor is said to be prolonged when the combined duration of both the first stage and second stages of labor is more than 18 hours. It is more common in a first pregnancy and in women over the age of 35 years.
Causes of Prolonged Labor
MalpresentationsThe normal position of the fetus is longitudinal with the fetal spine parallel to the mother's spine. The fetus lies in a completely flexed position with the chin touching the chest and the arms and legs flexed in front. The fetus normally faces the mother's back for a smooth delivery.
Any change in this position can cause prolongation in the duration in labor. A breech presentation in which the fetus is in the buttocks down position, a face presentation in which the fetus faces the mother's abdomen, or a deflexed position of the head in which the neck of the fetus is less flexed or even straight or extended can all cause prolonged labor.
Cephalopelvic Disproportion (CPD)
CPD is said to occur when the size of the fetal head is bigger then the size of the maternal pelvic passage or birth canal. In most pregnant women in labor, ligaments and joints tend to become more flexible, enabling them to relax more at the time of labor.
The baby's skull bones are also capable of overlapping each other normally to some extent, decreasing the size of the head ('moulding'). So, it is difficult to estimate by physical examination alone if CPD is actually present.
Problems with Uterine ContractionThe uterine muscle may fail to contract properly when it is grossly distended as in twin pregnancy and hydramnios (excess liquor amnii). Presence of tumours like fibroids in the uterine musculature can also affect uterine contraction.
Use of Sedatives and AnesthesiaExcessive use of painkillers or anesthesia can cause inefficient uterine action. They can also decrease the pain of normal labour and prevent voluntary effort by the mother to deliver the baby during the second stage of labor.
Cervical Dystocia or StenosisThe term cervical dystocia is used when the cervix fails to dilate properly and remains at the same position for more than 2 hours after the latent phase of labor. The cervix may fail to dilate when it is fibrosed due to previous operations like cone biopsy or due to the presence of tumors like cervical polyps and fibroids.
Signs and Symptoms of Prolonged Labour
- Labor extends for more than 18 hours.
- Patient looks exhausted and distressed. Dehydration may be present. Mouth may be dry due to prolonged mouth breathing.
- Pain may be more at the back and sides of the body, radiating to the thighs rather than from the uterus in the abdomen. This is due to excessive and prolonged pressure over the muscles and ligaments of the back.
- Labor pains may initially be severe, frequent and prolonged but later decrease and become very mild as the muscles become fatigued.
- Pulse rate is often high due to dehydration, exhaustion and stress.
- The large intestines are dilated and can be palpated along both sides of the uterus as large, thick structures filled with air. They give off the hollow sound of drums on tapping.
Risks of Prolonged Labour
Management / Treatment of Prolonged Labour
With the discovery of various drugs capable of accelerating labour, prolonged labour is a rarity nowadays.
Drugs like epidosin causes softening of tissues in the cervix. If the cervix fails to dilate in spite of adequate uterine contraction, epidosin or buscopan can be safely given to cause softening of the cervix.