Uterine contractions are the main forces that facilitate labour and delivery. When there is problem in uterine contractions, labour can be prolonged or obstructed. The strength, frequent, intensity and duration of uterine contraction can either make or mar labour and delivery.
According to wikipedia, the uterine smooth muscle contracts during the menstrual cycle and labour, and these are known as uterine contractions.
What is abnormal uterine contraction?
This is when the uterine contraction is capable of affecting the labour negatively and /or causing harm to either mother or fetus.
What are types of abnormal uterine contraction?
Abnormal uterine contractions are classified into two groups which are:
· Hypertonic uterine contractions
· Hypotonic uterine contractions
Hypertonic uterine contractions
In hypertonic labour pattern, uterine contractions are of poor quality and occur in latent phase of labour and the resting tone of the myometrium increases. Contractions usually become frequent but their intensity may decrease. The contractions are painful but ineffective in dilating and effacing the cervix and a prolonged phase may result.
Effects of hypertonic contractions on the mother
- Increase discomfort due to uterine muscle anoxia.
- Fatigue as the pattern continues and no labour progress occurs.
- Dehydration and increases incidence of infection if labour is prolonged.
- Stress on coping abilities.
Effects of hypertonic contraction on the fetus/neonate
- Early fetal distress due to more frequent uterine contractions with longer resting tone interfering with utero-placental exchange (hypoxia).
- Prolonged pressure on the head leading to cephalohematoma and caput succedaneum or excessive moulding.
How to manage hypertonic uterine contraction
- Bed rest and sedation to promote relaxation and reduce pain.
- Oxytocin infusion set up when CPD has been ruled out.
- Artificial rupture of membrane could be done before oxytocin.
Hypotonic Uterine Contractions
Hypotonic uterine action occurs in active phase of first stage of labour, though it may come in latent of labour. It is characterized by 2 – 3 or fewer contractions in 10 minutes.
Causes of hypotonic uterine contractions
- Over-stretching of the uterine muscles due to multiple pregnancy, large baby, polyhydramnios and grand multiparity
- CPD(cephalopelvic disproportion)
- Bladder and distention
Effects of hypotonic uterine contractions on the mother
- Increase infection due to prolonged labour
- Risk for post-partum haemorrhage
- Maternal exhaustion
- Stress on coping abilities
Effects of hypotonic contractions on the fetus/neonate
- Sepsis from maternal prolonged labour
- Fetal distress may occur due to prolonged labour
- There may be ascending infection to the fetus.
- Prolonged pressure on fetal head may lead to excessive moulding, caput succedaneum or cephalohaematoma.
- Fetal distress due to hypotonic contractions and increased resting tone resulting in interference of uteroplacental exchange
How to manage hypotonic uterine contraction
- Rule out CPD
- Improve quality of uterine contractions with oxytocin.
- Stress on copying abilities
- Risk of post-partum haemorrhage
- Maternal exhaustion.
General management of abnormal uterine contractions
- The woman is assessed very well to rule with cephalopelvic disproportion. Once there is no disproportion the labour is augmented with IV oxytocin, to improve quality and frequency of contractions
- In hypertonic uterine contraction, the woman is placed on bed rest with reduce pain.
- Pain relief can be administered to reduce pain.
- Monitor contractions regular at interval of 30 minutes for 10 minutes.
- Place the woman on partograph and maintain partograph protocol if the labour has been established i.e. active phase of labour
- Ensure the woman is hydrated, taking fluid at least every hour
- If the woman is dehydrated she can be placed on IV fluid
- Encourage the woman to change position; an upright position on bending forward can turn posterior position.
- Check fetal heart every 30 minutes
- Monitor maternal vital signs
- Non pharmacologic pain relieve can be used such as massaging and breathing exercise.
- Ensure that the woman eat light energy giving food. Maintaining energy level help to improve quality contractions.
- If the woman is on augmentation monitor and titrate the oxytocin infusion. Observe the effect on uterine contraction
- Monitor progress of labour i.e., cervical dilation and descent of presenting part. If progress fail within 4-6 hours inform obstetrician who may recommend caesarian section.
- Provide emotional support which is very important to help the woman and her partner cope with stress of prolonged labour.
