1st stage of labour

Last reviewed 01/2018

The diagnosis of labour is made when these criteria are met:

• history of regular, painful contractions: in well-established labour, a uterine contraction lasts for about 50-60 secs and occurs every 2-4 minutes.
• a show or breaking of waters
• progressive dilation of the cervix.

Dilation of the cervical os proceeds at about 1 cm per hour. The duration of this stage is influenced by uterine activity, fetal attitude and cephalopelvic relationship. It is said to be essentially independent of other factors: parity has only a minor effect; and race, multiple pregnancy and analgesia are unimportant.

The partogram should be started when labour is diagnosed.

• latent first stage of labour - a period of time, not necessarily continuous, when:
  • there are painful contractions, and
  • there is some cervical change, including cervical effacement and dilatation up to 4 cm
• established first stage of labour - when:
  • there are regular painful contractions, and
  • there is progressive cervical dilatation from 4 cm
• duration of the first stage
  • women should be informed that, while the length of established first stage of labour varies between women, first labours last on average 8 hours and are unlikely to last over 18 hours. Second and subsequent labours last on average 5 hours and are unlikely to last over 12 hours
• definition of delay in the established first stage
  • diagnosis of delay in the established first stage of labour needs to take into consideration all aspects of progress in labour and should include:
    • cervical dilatation of less than 2 cm in 4 hours for first labours
    • cervical dilatation of less than 2 cm in 4 hours or a slowing in the progress of labour for second or subsequent labours
    • descent and rotation of the fetal head
    • changes in the strength, duration and frequency of uterine contractions.

Reference:

1. NICE (September 2007).Intrapartum care.