2nd stage of labour

This is from full dilation to the birth of the baby. This stage of labour may be heralded by vomiting - probably due to vagal stimulation.

It involves vaginal dilation, with further descent of the fetus into the pelvic floor. There is further descent and the occiput reaches the perineum, emerges from under the pelvic arch and the head is delivered (delivery of the head occurs by extension of the head at delivery - restitution follows by external rotation). Delivery may require a controlled incision in the perineum (an episiotomy) to prevent tearing of the perineum in an uncontrolled manner.

The rest of the baby is delivered in a way which is best practically demonstrated. The umbilical cord is clamped and then cut (double clamping being used to isolate a section of cord from which fetal blood gases can sampled).

• passive second stage of labour:
  • the finding of full dilatation of the cervix prior to or in the absence of involuntary expulsive contractions
• onset of the active second stage of labour:
  • the baby is visible
  • expulsive contractions with a finding of full dilatation of the cervix or other signs of full dilatation of the cervix
  • active maternal effort following confirmation of full dilatation of the cervix in the absence of expulsive contractions

Duration and definition of delay in the second stage

• nulliparous women:
  • birth would be expected to take place within 3 hours of the start of the active second stage in most women
  • a diagnosis of delay in the active second stage should be made when it has lasted 2 hours and women should be referred to a healthcare professional trained to undertake an operative vaginal birth if birth is not imminent
• parous women:
  • birth would be expected to take place within 2 hours of the start of the active second stage in most women
  • a diagnosis of delay in the active second stage should be made when it has lasted 1 hour and women should be referred to a healthcare professional trained to undertake an operative vaginal birth if birth is not imminent
  • if full dilatation of the cervix has been diagnosed in a woman without epidural analgesia, but she does not get an urge to push, further assessment should take place after 1 hour
• oxytocin in the second stage
  • consideration should be given to the use of oxytocin, with the offer of regional analgesia, for nulliparous women if contractions are inadequate at the onset of the second stage
    
    
    
    
    
    
    
    

Reference:

1. NICE (September 2007).Intrapartum care.