Placenta Previa Flashcards

1
Q

The number of cases of placenta previa and its complications are increasing due to

A

The rising incidence of cesarean sections, and increasing maternal age

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2
Q

What is vasa previa?

A

It describes a fetal vessels coursing through the membranes between the internal os, and the fetal presenting part. Unprotected by placental tissue or the umbilical cord.

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3
Q

Type one vasa previa

A

A velamentous cord inserted in a single, or bilobed placenta

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4
Q

What is the type 2 vasa preview?

A

Fetal vessels running between lobes of a placenta with accessory lobes

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5
Q

What is the incidence of vasa previa?

A

1/2000 to 1/6000 pregnancies

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6
Q

Mortality rate of vasa previa

A

60%

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7
Q

Presentation of vasa previa

A
  • Fresh vaginal bleeding at the time of membrane rupture
  • Fetal heart rate abnormalities like decelerations, bradycardia, Sinusoidal trace, or fetal demise
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8
Q

Fetal blood volume

A

80-100 ml/kg

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9
Q

Risk factors of vasa previa

A
  • Placental anomalies such as bilobed placenta or succenturiate lobes
  • History of low lying placenta in the second trimester
  • Multiple pregnancy
  • IVF. As high, as 1/300.
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10
Q

Definition and grades of PLACENTA PREVIA

A

lacenta develops within the lower uterine segment and graded according to the distance between the lower placenta edge and internal os

Grade 1: minor lower edge
Grade 2: marginal lower edge reaches the internal ps
Grade 3: partial previa ….partially cover os
Grade 4: complete previa

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11
Q

AIUM grading of placenta previa

A

Placenta praevia - Placenta directly over the os
Low-lying - when lower edge is <20 mm from the os
Normal - lower edge 20 mm or more from the os

This is for pregnancies more than 16 weeks

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12
Q

Incidence of PP ?

A

1/200 pregnancies

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13
Q

Risk factors of placenta previa

A

Increased maternal age
Smoking
ART
Prior CS - increases as the number of C sections increase, increased risk if the prior CS was Elective or prelabour, increased risk if the CS to current pregnancy interval is less than 1 year

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14
Q

when to do screening for placenta previa

A

midpregnancy routine fetal anomaly

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15
Q

when to use the term low-lying placenta

A

if >16w, when placental edge is less than 20 mm from internal os

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16
Q

if lowlying or previa at routine fetal anomaly scan (18-22w), when to follow up

A

dollow-up u/s including tvs at 32 w

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17
Q

TVS in diagnosing placenta previa

A

safe and superior over TAS or Transperineal

18
Q

screening for placenta previa when

A

first screening in midpregnancy fetal anomaly scan (18-22w), if present..
repeat at 32 W, if present and asymptomatic..
repeat at 36 weeks, to inform discussion about mode of delivery

19
Q

how cervical lenght importnant in management of Placenta previa

A

A short cervical length on TVS before 34 weeks of gestation increases the risk of preterm emergency delivery and massive haemorrhage at caesarean section.

20
Q

when women should be attend to hospital in 3rd trimester

A

if she experienced any bleeding (spotting, contractions or pain)

including vague suprapubic period-like aches

21
Q

Is there a place for cervical cerclage in women with placenta praevia or a low-lying placenta?

A

The use of cervical cerclage to reduce bleeding and prolong pregnancy is not supported by sufficient evidence

22
Q

do women with placenta previa need to get course of corticosteroids

A

yes at 34 to 35+6 W

  • give it before 34 w if high risk of premature labour
23
Q

Do we give tocolytics to women with symptomatic pp

A

yes for 48 hours to facilitate adminstration of corticosteroids

If delivery is indicated based on maternal or fetal concerns, tocolysis should not be used in an attempt to prolong gestation.

24
Q

Suspicion should be raised for placenta previa if

A
  • vaginal bleeding after 20 weeks of gestation
  • high presenting part
  • abnormal lie
  • painless of provoked bleeding irrespective of previous imaging results
25
Q

Placental migration from lower segment during 2nd or 3rd trimester is less likely to occur if

A
  • placenta is posterior
  • placenta covering the internal os
  • there is a previous cs
26
Q

Any home based care for PP requires

A
  1. Close proximity to the hospital
  2. Ready access to hospital
  3. Constant presence of companion
  4. Full informed consent by the women
27
Q

When to admit women with pp

A

If major pp who have previously bled should be admitted from 34 weeks

28
Q

At what gestation should planned delivery occur?

A

Late preterm (34+0 to 36+6 weeks of gestation) delivery should be considered for women presenting with:
- placenta praevia or a low-lying placenta
- a history of vaginal bleeding or other associated risk factors for preterm delivery.

29
Q

Delivery for uncomplicated pp should be when?

A

Between 36 to 37 weeks

30
Q

In what situations is vaginal delivery appropriate for women with a low-lying placenta?

A

In women with a
- third trimester
- asymptomatic low-lying placenta
the mode of delivery should be based on the clinical background, the woman’s preferences, and supplemented by ultrasound findings, including the distance between the placental edge and the fetal head position relative to the leading edge of the placenta on TVS.

31
Q

Most serious complications of PP at delivery

A

massive obstetric hmge
need of blood transfusion or hysterectomy

32
Q

What anaesthetic procedure is most appropriate for women having a caesarean section for placenta praevia?

A

Regional anaesthesia is considered safe and is associated with lower risks of haemorrhage than general anaesthesia

33
Q

What to do if the placenta is transected during the uterine incision?

A

immediately clamp the umbilical cord after fetal delivery to avoid excessive fetal blood loss

34
Q

What to do if pharmacological measures fail to control haemorrhage after pp cs

A

initiate intrauterine tamponade and/or surgical haemostatic techniques sooner rather than later.

35
Q

if both medical and surgical intervention fail to control hmge after PP Cs

A

Early recourse to hysterectomy is recommended

36
Q
A
37
Q

What is cell salvage

A

A method of collecting blood that you may lose during operation

38
Q

May cell salvage considered in cs of PP patient

A

Yes it may be considered in patient with high risk of massive hmge or who refuse donor blood

39
Q

Increased risk of obstetric hmge in labour of pp

A

12 times more than elective cs

40
Q

During CS, if place ta failed to separate by usual measures

A

Leavit in place and close, start conservative management or hysterectomy

41
Q

Management of placental retention

A
  • prophylactic antibiotics to reduce risk of infection and bleeding
  • neither Methotrexate of arterial embolization is of a benefit
  • follow up with us and bhcg to check if it falls continuously