Impact of Timing of Neuraxial Analgesia on Obstetric, Anesthesiologic and Neonatal Outcomes in Induced Labour

The primary objective is to compare the duration of the first stage of labour (measured in minutes) between women who received early neuraxial analgesia in the latent phase of the first stage and those who received it in the active stage. First stage duration is the time elapsed from the onset of labour, as diagnosed by an experienced obstetrician, until 10 centimetres of cervical dilation is reached.

The co-primary objective is to compare the duration of the second stage (measured in minutes) between the two populations.

Second stage duration is the time from 10 centimetres of cervical dilation to birth.

Data on these outcomes are recorded by the obstetric team in the patient's chart during labour.

The incidence of operative deliveries by obstetrical suction cup for lack of progression of the presented part or presence of fetal heartbeat abnormalities was assessed. Data relating to the mode of delivery and events are recorded in the patient's medical chart by the obstetric team during labour.

The incidence of episitomy due to lack of progression of the presented part or presence of fetal heartbeat abnormalities was assessed. Data on this outcome is recorded in the patient's medical chart by the obstetric team during labour.

The incidence of caesarean section in labour was assessed. The causes of caesarean section considered were: first stage prolongation, second stage prolongation, fetal heartbeat abnormalities.Data on this outcome is recorded by the obstetric team in the patient's chart during labour.

The incidence of grade I, II, III obstetric lacerations was evaluated. Data on this outcome is recorded by the obstetric team in the patient's chart during labour.

The amount of oxytocin used during labour was assessed. Data on this outcome is recorded by the obstetric team in the patient's chart during labour.

The amount was measured in units per minute.

The incidence of epidural catheter repositioning for inadequate analgesia was measured.

Analgesia was defined as inadequate if the Visual Analogue Scale > 4 30 minutes after analgesia was administered.

During labour analgesia, this event was recorded by the anaesthetist on duty in the anaesthesia chart.

Fetal heart rate abnormalities occurring within 30 minutes of local anaesthetic or neuroaxial opioid administration have been recorded. The American Congress of Obstetricians and Gynecologists classification was used for the identification of trace abnormalities. Abnormal foetal heart rate are recorded as they occur by the obstetrician in patient's medical chart.

The Apgar score is assessed by a paediatrician using a scale from 0 to 10 at 1 minute and 5 minutes after birth. The information is then recorded in the baby's and mother's medical records.

The arterial pH of the umbilical cord is assessed.After delivery the obstetrician takes a sample of umbilical arterial blood to measure pH. The information is then recorded on baby's and mother's medical chart.

This outcome is assessed from the moment of birth until 2 hours after delivery. The event is recorded in the mother's medical record.

The need for a 'rescue' epidural was assessed. The time of administration of each epidural top up was recorded both on patient medical chart and on anaesthesia medical chart. When, after initial benefit, the patient experienced a recurrence of pain (Visual analogue Score greater than four) and needed an additional top up within 60 minutes from previous epidural bolus, the event was registered.