Cardinal Movements of Birth, Perineal Lacerations, & Placental Attachment

engagement

into the pelvic inlet (can occur before labor)

descent

into the birth canal

flexion

fetal head descends, meets resistance, and flexes chin to chest

internal rotation

fetal head rotates to fit diameter of pelvis

extension

vulva opens, causing fetal head to extend backwards

restitution

shoulders rotate to anteroposterior position

expulsion

shoulders slip under symphysis pubis

List the order of movements

engagement, descent, flexion, internal rotation, extension, restitution, external rotation, expulsion

first-degree laceration

fourchette, perineal skin, and vaginal mucous membrane

second-degree laceration

perineal skin, vaginal mucous membrane, underlying fascia, and muscles of the perineal body

third-degree laceration

perineal skin, vaginal mucous membranes, and perineal body and the anal sphincter

fourth-degree laceration

same as third-degree but extends through the rectal mucosa to the lumen of the rectum

placenta accreta

chorionic villi attach directly to the uterine myometrium

placenta increta

myometrium is invaded

placenta percreta

myometrium is penetrated