Normal labour: regular, frequent uterine contractions with cervical changes and descent of the presenting part
Stages of labour
I – Latent: up to 3-4 cm dilation and effacement (false labour, pre-labour)
Active: 4cm to full dilation → abnormal if <0.5cm/hr over >4hours
II – Full dilation to delivery → abnormal if no descent over >1hour pushing
III – Delivery of placenta
IV – 2 hours postpartum (may be up to 6 weeks)
Dystocia – arrest of progression of labour
Assess the the 5 P’s:
- Power:
- Strength of contractions (not on monitor, must feel)
- Must have rest in between ( beware of tachysystole, coupling)
- May be augmented with oxytocin
- Passenger
- Size
- Lie: longitudinal/transverse
- Presentation: face (mentum – anterior can deliver vaginally), brown (frontum), vertex (occiput), transverse (shoulder), breech (sacrum)
- Position: OA 8.5cm diameter, OP 9cm, brow 13cm
- Attitude: asynclitism
- Passage
- Psyche
- Pain
- Reduce stimuli (maternal movement, ARM for decompression)
- Activate peripheral sensory receptors (water, TENS)
- Enhance descending inhibitory pathway (hypnosis, music)
- Narcotics (with antiemetic)
- Entanox (inhaled N2O)
- Do not use sedatives/hypnotics
- Epidural: most effective, does not lengthen 1st stage
- Pudendal: use in 2nd stage (10cc local under ischial spines)
- Perineal infiltration
Arrest of 1st stage: amniotomy, oxytocin augmentation, therapeutic rest with analgesia (epidural), C-section
Oxytocin augmentation (drip because of short t1/2 titrated to contractions)
- Unsatisfactory in 1st or 2nd stage
- Inadequate uterine contractions
- After analgesia, rest, amniotomy
- Prior to operative vaginal delivery to achieve adequate contractions
- Beware of hyperstimulation