Placenta Praevia Flashcards
Placenta previa is when the placenta is wholly or partially attached to the lower uterine segment. How many classes of placenta previa are there?
1 - 6
2 - 4
3 - 2
4 - 1
3 - 2
- partial = part of placenta covers internal os
- complete = whole placenta covers internal os
What is the incidence of placenta previa?
1 - 40-50%
2 - 25-30%
3 - 5-10%
4 - 0.4-0.8%
4 - 0.4-0.8%
- peak incidence is in 30-40 y/o
The incidence of placenta previa is 0.4-0.8%, but which of the following is NOT a risk factor that increases the risk of placenta previa?
1 - previous c-section
2 - nulliparity
3 - previous placenta previa
4 - advanced age
5 - multiple pregnancy
6 - smoking
7 - succenturiate placenta lobe
2 - nulliparity
- multiparty is a risk factor
What is the reoccurrence rate of placenta previa in future pregnancies?
1 - 0.4-0.8%
2 - 4-8%
3 - 15-20%
4 - 30-40%
2 - 4-8%
In addition to the placenta previa, patients who have had multiple C-sections may also experience placenta accreta. What is this?
1 - placenta develops on fundus but blocks fallopian tubes
2 - placenta detaches from uterine wall
3 - placenta grows too deeply into the uterine wall
4 - can be all of the above
3 - placenta grows too deeply into the uterine wall
In patients with placenta previa, they may be completely asymptomatic and it may only be detected during routine imaging. However, what is the most common presentation?
1 - abdominal mass
2 - pelvic pain, vaginal bleeding and UTI
3 - UTI and pelvic pain
4 - painless vaginal bleeding
4 - painless vaginal bleeding
- ranges from spotting to life threatening haemorrhage
- uterus is typically non-tender and soft
If symptoms of placenta previa do present with painless vaginal bleeding, which trimester do they typically occur in?
1 - 3rd
2 - 2nd
3 - 1st
1 - 3rd
- mean is 30 weeks gestation
How is placenta previa diagnosed?
1 - bimanual examination
2 - abdominal ultrasound
3 - pregnant abdominal examination
4 - blood test
2 - abdominal ultrasound
Abdominal ultrasound typically diagnoses placenta previa. When is it typically picked up?
1 - week 12
2 - week 20
3 - week 28
4 - week 32
2 - week 20
- anomaly scan
- if identified, then scanned again at week 32 weeks to make diagnosis
If a women is pregnant and presents with vaginal bleeding, which of the following is an unlikely differential diagnosis?
1 - miscarriage
2 - placenta abruption
3 - adenomyosis
4 - cervical ectropian
3 - adenomyosis
- does not typically cause vaginal bleeding in pregnancy
Do all placenta previa remain throughout pregnancy?
- no
- 90% of cases resolve spontaneously
If bleeding is heavy and placenta previa is suspected, what examination must NOT be performed?
1 - digital examination
2 - ultrasound
3 - group and save and crossmatch
4 - rectal examination
1 - digital examination
- may cause major haemorrhage
- if only minor bleeding, a speculum may be used to examine the patient
Which tests must be performed in a patient with placenta previa and risk of bleeding?
1 - FBC
2 - coagulation profile
3 - group and save and crossmatch
4 - rhesus status
5 - all of the above
5 - all of the above
What tells the doctor that the baby is ok?
1 - ultrasound
2 - maternal feeling of movement
3 - CTG
4 - all of the above
4 - all of the above
What test can be used to assess for the presence of foetal blood in maternal circulation, which can occur during haemorrhage and affects Rhesus status?
1 - FBC
2 - Kleihauer test
3 - blood smears
4 - blood cross matching
2 - Kleihauer test
Why should renal function be assessed in individuals with placenta previa?
1 - risk of hypovolaemia
2 - risk of polyhidrosis
3 - risk of pyelonephritis
4 - all of the above
1 - risk of hypovolaemia
- will see low urine output and drop in BP due to excessive blood loss, cause kidney injury
All patients who are diagnosed with placenta previa should be advised to avoid which of the following?
1 - penetrative intercourse
2 - vaginal douching
3 - vaginal examination unless necessary
4 - all of the above
4 - all of the above
If there is maternal or foetal compromise when the mother begins to bleed, what should occur asap?
1 - vaginal birth
2 - abortion to save the mother
3 - c-section
4 - any of the above
3 - c-section
A c-section may be needed if a patient has placenta previa. What distance from the internal os is generally an indication that a c-section should be performed?
1 - <0.5mm
2 - <2cm
3 - <4cm
4 -<6cm
2 - <2cm
- if 2cm or closer to internal os, c-section is advised
- Prophylactic and intra-operative antibiotics are recommended.
Is a c-section required in all patients with placenta previa?
- no
- if baby becomes engaged and head passed edge of placenta, vaginal birth may be necessary
In a patient with placenta previa, they may need to deliver earlier than planned if they experience vaginal bleeding. The mother may be given corticosteroids to help develop the foetus lungs. Below what week of gestation should corticosteroids be given if the baby needs to be delievred?
1 - <38 weeks
2 - <37 weeks
3 - <35 weeks
4 - <34 weeks
4 - <34 weeks
In a patient with placenta previa, what medication may be given in an attempt to delay labour to provide maximum benefit from corticosteroids therapy for the foetus?
1 - Oxytocins
2 - Prostaglandins
3 - Hormone inhibitors
4 - Tocolytics
4 - Tocolytics
- induce smooth muscle relaxation, so stop contractions
Pregnant women who has develop vaginal bleeding with placenta previa and who are rhesus negative should be given anti-D within what time frame from the onset of bleeding?
1 - <12 hours
2 - <48 hours
3 - <72 hours
4 - <120 hours
3 - <72 hours
What is the major maternal risk factor in a patient with placenta previa?
1 - sepsis
2 - post-partum haemorrhage
3 - uterine rupture
4 - UTI
2 - post-partum haemorrhage
- lower uterus does not contract as well, therefore venous sinuses are not as efficiently occluded
