Haemorrhage during the second half of pregnancy (Third trimester haemorrhage)- Placenta Previa and Placental abruption. Flashcards
Define placental abruption
The partial or complete separation of the placenta from the uterus prior to delivery/after 20 wks gestation causing Subsequent hemorrhage from both maternal and fetal vessels.
Rf for abruptio placentae
Vascular changes
- Hypertension (most common cause)
- Preeclampsia/eclampsia
(Abdominal) trauma (up to 10% of cases):
car accidents, falls, iatrogenic (e.g., post-amniocentesis)
Sudden decrease in intrauterine pressure (after delivering first kid in mx pregnancy)
Previous abruption, chorioamnionitis, prolonged rupture of membranes, short umbilical cord
Maternal age: < 20 years and > 35 years
Alcohol and cigarette consumption, cocaine use
Clinical features following placental abruption
revealed abruptio placentae:
Continuous, dark, vaginal bleeding
concealed abruptio placentae: 20% of cases, the hemorrhage is mainly retroplacental; vaginal bleeding does not occur
-the reteroplacental hemorrhage is only at the middle but the margins are in tact
Pain: shows location of abruption
Abdominal: anterior wall abruption
Back pain: posterior walls abruption
Uterine tenderness : blood dissects through the myometrial wall and causes the characteristic tender, woody/rigid uterus on palpation.
Premature labour d/2 contractions of uterus to squeeze arteries and stop bleeding
fetal distress
deccelerations on CTG
what is fetal distress
characteristic changes in the fetal heart rate (FHR) in response to fetal hypoxia and metabolic acidosis (usually secondary to placental insufficiency).
indication for either intrauterine resuscitation or immediate delivery (cesarean or, if imminent, vaginal delivery)
signs of fetal distress
(FHR > 160-180/min), fetal bradycardia (FHR < 110/min), loss of baseline variability, variable decelerations, and recurrent late decelerations
what are decelerations
decrease in the fetal heart rate that is ≥ 15 beats/minute and lasts ≥ 15 seconds.
Early decelerations indicate fetal head compression during uterine contractions and are not a cause for concern.
Recurrent variable decelerations might indicate cord compression.
Late decelerations usually occur with uteroplacental insufficiency.
dg of abruptio placenta
rapid dg is essential for maternal and fetal survival
1) Ultrasound (transabdominal, transvaginal):
- shows placental position and a possible retroplacental hematoma
- can Monitor vital signs of the fetus (heartbeat, fetal movement)
- used to rule out placenta previa in unclear cases
2) Fetal heart rate monitoring
Laboratory tests: CBC, coagulation factors
rx of abruptio placentae
general rx
- maintain haemodynamics
- maintain airways
- transfusion
specific rx
at 34th week
-corticosterioids for fetal lung development (bethametasone)
-tocolysis w/ b2 agonist, nifedipine)
34-36th wk
delivery
acute sx and a live fetus
emergency cesarean
acute sx and a dead fetus
-vaginal delivery and open amniotic sac
complication of abruptio placenta
Abruptly my mum preaches in church
intreuterine death d/2 severe fetal hypoxia
Preterm labour
maternal DIC
maternal shock
couvelaire uterus
- Retroplacental hemorrhage can extend through uterus into the peritoneum.
- myometrium weakens, with possible subsequent uterine rupture during contractions.
define placenta previa
esence of the placenta in lower uterine segment(lower 1/3rd), which might lead to partial or full obstruction of the neck of the uterus with high risk of hemorrhage
Normal position is fundal area
Early pregprevia: self resolves d/2 stretching of uterus
classification of placena previa (based on how much the placenta covers the cervical oeidice
Low-lying/ 1st degree previa: lower 1/3rd of the placenta lies less than {{2 cm}}from the internal cervical os
Margina/ 2nd degree previa: placenta reaches the internal cervical os w/o covering it
Partial / 3rd degree previa: placenta partially covers the internal cervical os but not when the cervix dilates
Complete previa (total previa): placenta completely covers the internal cervical os
RF for placenta preveia
Reduced blood supply to upper uterus
Maternal age > 35 years, multiparity,
Multiple pregnancies
short intervals between pregnancies(slow recovery)
Previous curettage previous cesarean section
Previous placenta previa, previous/recurrent abortion
Smoking
clinical features of placenta previa
occurs in 20wks gestation
stops for 1-2 hrs
continues after birth
Cont/immt
Sudden, painless, bright red vaginal bleeding
hypotension in cases of severe bleeding
cause of preterm delivery in 45% of cases
no fetal distress but excessively e bleed can cause hypoxia
Soft, nontender uterus
dg of placenta previa
Pre natal Transvaginal ultrasound to assess the position of the placenta
Digital vaginal examinations are contraindicated in cases of hemorrhage of unknown cause!
rx of placenta previa before 37 weeks
W/ active beed/fetal distress immediate delivery w/ c-section
in cases w/o bleeding/ fetal distress expectant management is enough
