Hello and welcome to the zero to finals podcast. My name is Tom and in this episode I'm going to be

talking to you about the onset of labour. And you can find written notes on this topic at

zero to finals.com slash onset or in the labour and delivery section of the zero to finals obstetrics and gynecology book.

So let's get straight into it.

Labor and delivery normally occur between 37 and 42 weeks gestation.

There are three stages of labour.

The first stage, which is from the onset of labour or true contractions until 10 centimetres of cervical dilatation, so when the cervix is dilated

to 10 centimetres, the second stage of labour is from 10 centimetres of cervical dilatation until delivery of the baby

and the third stage is from the delivery of the baby until the delivery of the placenta.

Let's talk about the first stage of labour.

The first stage of labour is from the onset of

labour with true contractions until the cervix is fully dilated to 10 centimetres. It involves

cervical dilatation, which is where the cervix opens up, and cervical effacement, which is where the cervix gets thinner. The show refers to

the mucus plug in the cervix, which prevents bacteria from entering the uterus during the

pregnancy, falling out and creating space for the baby to pass through. The first stage of labour has three phases,

the latent phase, which is from zero to three centimetres dilation of the cervix, and this progresses

at around 0.5 centimetres per hour. During the latent phase, there are irregular contractions. Next is the active phase,

which is from three centimeters to seven centimeters of dilation of the cervix, and this progresses

at around one centimeter per hour, and during the active phase there are regular contractions

and the transition phase which is from 7 cm to 10 centimeters of dilation of the cervix

and this progresses at around 1 cm per hour and there are strong and regular contractions during the transition phase.

Let's talk a little bit about Braxton Hicks contractions.

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