Certain risk factors increase the risk of a perineal laceration extending to involve the anal sphincter. A woman with multiple risk factors may benefit from interventions directed at reducing the overall risk of laceration.


Risk factors:

(1) macrosomia, typically > 4,000 grams

(2) maternal race

(3) primigravida status

(4) type of delivery

(5) presentation of the infant


Maternal race associated with greater risk:

(1) Indian (Asia)

(2) Filipino


Manner of delivery:

(1) vacuum delivery

(2) forceps delivery



(1) occiput posterior

(2) breech


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