- A partogram is used to monitor the progress of labour once the labour is established.
- The onset of labour is defined as regular, painful uterine contractions resulting in progressive cervical effacement and dilatation.
Maternal Vital Signs
The maternal temperature should be monitored every 4 hours during labour. If the mother is pyrexic, underlying infection should be suspected. Possible infections include chorioamnionitis, group B streptococcus infection and urinary tract infection. Perform a full blood count (white blood count), CRP, urine dipstick and blood culture to identify the source of the infection.
Chorioamnionitis is suspected when the maternal temperature is >38°C and two of the following signs are present :
- WBC count >15,000 cells/mm3
- Maternal tachycardia >100 beats per minute
- Fetal tachycardia >160 beats per minute
- Tender uterus
- Foul smelling discharge
Maternal Respiratory Rate
The maternal respiratory rate could increase if the mother is pyrexic.
Maternal Blood Pressure
The maternal blood pressure should be monitored every 4 hours during labour, especially in those who have pre-eclampsia. It is important to record the blood pressure after the delivery of the placenta as excessive blood loss could lead to hypotension.
The maternal pulse should be monitored every hour. Maternal pyrexia can cause an increase in both maternal pulse rate and fetal heart rate.
Fetal Heart Rate
The fetal heart rate should be assessed every 15 minutes using either a Pinard stethoscope or Doppler transducer. If non-reassuring or abnormal fetal heart rate (<100bpm or >180bpm) is recorded, the suspicion of fetal distress should be raised and prompt actions should be taken to assess the fetal condition.
Management of non-reassuring or abnormal fetal heart rate:
- Start CTG monitoring
- Oxygen - improved fetal oxygenation.
- Maternal position - left lateral position reduces aortocaval compression, this increases cardiac output and uterine blood flow.
- Intravenous fluid administration - increases blood volume and placental perfusion.
- Oxytocin should be discontinued until the fetal heart rate and uterine activity return to acceptable levels.
- Fetal blood sampling should be considered when pathological features are shown on the continuous electronic fetal monitoring. Urgent birth is often required when the fetal blood pH >7.20.
Pregnant women are encouraged to mobilise and adopt the most comfortable positions during labour. Positions such as semi-recumbent, kneeling, or left lateral position tends to increase the dimensions of pelvic outlet. They should not lie flat on their back because this will result in aortocaval compression where the gravid uterus compresses the main blood vessels and reduces the cardiac output, leading to maternal hypotension and fetal distress.
Urine / Liquor State
- Presence of protein in the urine could suggest pre-eclampsia or contamination by the liquor fluid.
- Presence of glucose in the urine could suggest underlying diabetes mellitus during pregnancy.
- Presence of ketones in the urine could suggest maternal starvation where the body cannot get enough glucose to produce energy and body fats are utilised instead. This will lead to metabolic acidosis which reduces the contractibility of the uterus, thus prolonging the labour.
- Presence of blood in the urine could suggest urinary tract infection or obstructed labour.
- Clear - indicates the membranes have ruptured
- Meconium - might indicate fetal distress; advise continuous electronic fetal monitoring and fetal blood sampling
- Blood - might indicate placental abruption
The time of rupture of membranes is usually recorded on the partogram because the longer the time, the higher the risk of ascending infection.
Indicators of Labour Progress
Fifths of palpable fetal head per abdomen
The mother's abdomen is palpated every 4 hours to assess the level of the fetal head. It is often used to determine the likelihood of a fetus to be born vaginally by instrumental delivery, or by Caesarean section, when there is slow progress in labour.
Position is the orientation of the fetal head in the maternal pelvis. It is assessed transvaginally by locating the position of anterior fontanelle, sagittal suture and posterior fontanelle. Occipito-posterior position is associated with difficult labour.
Moulding is the overlapping of skull bones when the fetal head passes through the birth canal. It is normal to have some degree of moulding during labour but excessive moulding might indicate cephalo-pelvic disproportion and Caesarean section is then required.
Degree of moulding
- The bones are separated normally
- The bones are touching each other
- The bones are overlapping but can be easily separated with digital pressure
- The bones are overlapping and cannot be separated by digital pressure (sign of cephalo-pelvic disproportion)
Caput succedaneum is the swelling of the tissue over the presenting part of the fetal head caused by the pressure during labour when the fetal head is forced down onto dilating cervix. The presence of caput usually indicates prolonged length of labour.
The diameter of the internal os of the cervix is measured in centimetres by vaginal examination from 0cm to 10cm, with 10cm corresponding to complete cervical dilatation. In the active phase of the first stage of labour, cervical dilatation is usually at the rate of 1cm/hour in primigravida and 2cm/hour in multigravida.
Delay is suspected when the progress of cervical dilatation is less than 2cm in 4 hours.
- Consider amniotomy if membranes intact.
- Advise vaginal examination 2 hours later.
- If the progress is less than 1cm, consider oxytocin for primigravida. In multigravida, abdominal palpation and vaginal examination should be performed to determine the presentation and station before starting the oxytocin to reduce the risk of uterine rupture.
- Advise continuous electronic fetal monitoring once oxytocin is started.
- Repeat the vaginal examination in 4 hours after oxytocin infusion and consider Caesarean section if the progress is less than 2cm.
The level of head descent can be assessed by transvaginal examination. It is crudely measured in relation to the level of ischial spines. Station 0 means the head is at the level of ischial spines; station +1cm means it is 1cm below and station -1cm means it is 1cm above the ischial spine level.
The contraction of the uterus should be assessed every 30 minutes during labour. 3-5 regular, strong contractions in 10 minutes are usually aimed for the second stage of labour.
- Syntocinon is a synthetic form of oxytocin indicated for the induction and augmentation of labour.
- It should not be given as a large bolus because it can cause a marked transient fall in maternal blood pressure.
- It should be given as a dilute solution by continuous intravenous infusion or as an intramuscular injection.
- It is also given after the delivery of baby to reduce postpartum haemorrhage.
- Oxytocin infusion should be discontinued when fetal distress or hyperstimulation of the uterus is suspected.
Any analgesia given during labour should be recorded.
- Inhaled Entonox
- Intramuscular diamorphine
- Intramuscular pethidine
- Epidural analgesia
- All intravenous fluid eg, normal saline, Hartmann's solution, that is administered should be recorded. It is important to make sure the mother is not dehydrated during labour.
- Check the frequency of bladder emptying, as a full bladder will often prevent the fetal head from entering the pelvic brim, causing slow progress in labour.
- Patients who are on epidural analgesia are particularly prone to urinary retention due to reduced bladder sensation, and therefore catheterisation might be required.
Factors Determining Slow Progress In Labour
- 3-5 regular, strong uterine contractions per 10 minutes, each lasting for one minute, are considered satisfactory for labour.
- Uterine activity can be assessed by manual palpation of the uterus per abdomen or using the cardiotocography (detects the frequency but not the intensity of contraction).
- Ideally, the fetus should be in the longitudinal lie, cephalic presentation and occipito-anterior position for vaginal delivery.
- Large fetal size (macrosomia >4500g), malpresentation (breech, brow, face, or shoulder), abnormal lie (transverse, oblique) and multiple pregnancies could result in slow progress in labour.
- Fetal size, presentation, lie and multiple pregnancies can be assessed by abdominal palpation and ultrasound scans.
- Gynaecoid pelvic type is the ideal pelvic shape for vaginal delivery. Android and platypelloid are the less favourable pelvic types. Anthropoid pelvic type is often associated with delivery of fetus in the occipito-posterior position.
- Pelvic masses such as uterine fibroids and ovarian tumours could obstruct the birth canal, causing slow progress in labour.
- The likelihood of cephalo-pelvic disproportion could be assessed by trial of labour or clinical pelvimetry where the parameters of pelvic inlet, midcavity and pelvic outlet are measured.
- NHS. Partogram. http://www.perinatal.nhs.uk/birthnotes/pages/bn1011.pdf (accessed 13/12/11)