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 perineal tears. And you can find written notes on this topic at

zero tofinals.com slash perineal tears or in the labour and delivery section of the Zero to Finalsinals obstetrics and gynecology book.

So let's get straight into it.

A perineal tear occurs when the external vaginal opening is too narrow to accommodate the baby.

This leads to the skin and tissue in that area tearing as the baby's head passes through.

Perineal tears can range from a graze to a large tear involving the anal sphincter, which is called a third

degree tear, and the rectal mucosa, which is a fourth degree tear. Perineal tears are more common with the first

birth when the woman is Nali Paris, with large babies over four kilograms, with shoulder

dystosia, in women of Asian ethnicity, when the baby is in an occipito posterior position, and with instrumental

deliveries. Let's talk about the classification. There are four degrees of perineal tears,

and as the degrees go higher, the tears become worse with more injury to the tissue.

The first degree tear is when there's injury limited to the frenulum of the labia minora,

which is where the labia minora meet posteriorly and to the superficial skin.

A second degree tear involves the perineal muscles but is not affecting the anal sphincter.

A third degree tear involves the anal sphincter but not affecting the rectal mucosa and a fourth degree tear involves the rectal mucosa.

Third degree tears can be sub-categorized as 3A involving less than 50% of the external anal sphincter,

3B involving more than 50% of the external anal sphincter,

and 3C involving the external and the internal anal sylincter and 3C involving the external and the internal anal sylter.

Next let's talk about management. First degree tears usually do not require any sutures. When a perineal tear larger than a first degree occurs, the mother usually requires sutures to correct the injury.

A third or fourth degree tear is likely to need repairing in theatre.

Additional measures are taken to reduce the risk of complications.

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