PPH - physiology

Question 1

What are the 4 T’s & % incidence

Answer 1

Tone 70%
Tissue 10%
Trauma 20%
Thrombin 1%

Question 2

What are abnormalities of uterine contraction (5) - Tone

Answer 2

exhaustion of uterine muscles
over distended uterus
chorioamnionitis
anatomic distortion of the uterus
uterine-relaxing agents

Question 3

Clinical risk factors for exhaustion of uterine muscles

Answer 3

precipitous labour
prolonged labour (& pushing stage)
augmentation or induction of labour
prior PPH

Question 4

Clinical risk factors for over-distended uterus

Answer 4

polyhydramnios
multiple gestation (twins ++)
fetal macrosomia (think uncontrolled GDM)

Question 5

What are clinical risk factors for chorioamnionitis

Answer 5

prolonged rupture of membranes >18hrs
fever in labour
known pathologic colonization

Question 6

clinical risk factors for anatomic distortion of uterus

Answer 6

fibroids or uterine anomalies
placenta previa/ low lying placenta
bladder distension

Question 7

clinical risk factors for uterine-relaxing agents

Answer 7

given tocolytics or halogenated anesthetics

Question 8

How does Tissue cause PPH

Answer 8

retained placenta tissue or clots prevent occlusion of uterine blood vessels

Question 9

clinical risk factors for retained placenta, placental fragments, clots, lobe, or membranes

Answer 9

manual removal of placenta
succenturiate/ accessory lobe

Question 10

clinical risk factors for abnormal placentation (previa, accreta, increta, percreta)

Answer 10

previous uterine surgery
preeclampsia

Question 11

What are causes and risk factors of trauma

Answer 11

.lacerations and hematomas of vagina, perineum, or cervix - epis, operative delivery, shoulder dystocia
.extension of c/s incision - malpresentation/ position/ deep engagement
.uterine rupture - previous uterine surgery
.uterine inversion - fundal placental, excessive cord traction, grand multiparity

Question 12

what causes Thrombin to be an issue during PPH

Answer 12

1. pre-existing coagulation disorders
2. coagulation disorders acquired in pregnancy or labour

Question 13

clinical risk factors for coagulation disorders acquired in pregnancy or labour

Answer 13

severe infection
placental abruption
intrauterine fetal death
amniotic fluid embolism
hypertensive disorders of pregnancy
idiopathic thrombocytopenic purpura

Question 14

majority of PPH cases occur (with/without) known risk factors

Answer 14

without

Question 15

history of PPH = _____________ in risk of PPH 2nd pregnancy

Answer 15

threefold increase

Question 16

Strong risk factors for severe PPH

Answer 16

known before birth: placenta previa, uterine fibroids
known after birth: cervical laceration, high vaginal laceration, retained placenta

Question 17

Moderate risk factors for severe PPH

Answer 17

known b4 birth: grand-multip, multifetal gestation, chorioamnionitis, hypertensive disorders of pregnancy, placenta abruption, hxPPH
known after birth: 3rd or 4th degree year, operative delivery (forceps/vacuume), bw >4500g, c/s

Question 18

weaker risk factors for severe PPH

Answer 18

polyhydramnios
age <20 or >40
previous c/s
32-36wks gestation
IOL, prime, prelabour c/s, BMI>30