Placenta Previa

1. Definition

a) When the placenta is implanted partially or completely over the lower uterine segment adjacent to internal os is called placenta previa.

2. Risk Factors-(CAMPS)

a) Cesarean section history.

b) Aged women.

c) Multiparous women.

d) Placenta size abnormality.

e) Smoking, Scar.

3. Types of degrees

a) Type I

i) Low lying.

ii) Major part attach to upper segment.

iii) Lower margin attach to lower segment but not upto os.

b) Type II

i) Marginal.

ii) Placenta reaches the margin of internal os but does not cover it.

c) Type III

i) Incomplete or partial central.

ii) Covers internal os partially.

iii) Covers internal os fully when it is closed but does not covers entirely when fully dilated.

d) Type IV

i) Central or total.

ii) Placenta completely covers internal os even after full dilation.

Mild degree- Type I and Type II anterior wall attachment

Major degree- Type II posterior wall attachment, Type III, IV

4) Causes of bleeding-

a) As the placental growth slows down in later month and lower segment progressively dilates, the inelastic placenta is sheared off the wall of uterine segment.

b) Bleeding due to separation of placenta due to trauma by-

i) Vaginal examination.

ii) Coital act.

iii) High rupture of membrane.

c) Blood loss is always maternal.

5) Placental migration-

a) With progressively increase in length of lower segment the lower placental edge relocates away from cervical os.

b) Due to trophotropism(Growth of trophoblastic tissue towards the fundus).

6) Clinical features-

a) Symptoms

i) Sudden, painless, causeless, recurrent vaginal bleeding not related to any trauma.

b) Signs-

i) Anemia.

ii) Shock.

iii) Abdominal examination

-Uterus-

- Relaxed and soft.

- Contraction are absent.

- No tenderness is seen.

- Floating head, unstable lie.

- IUD takes place if there is major separation.

iv) Vulval inspection to note-

- Character of blood.

- Amount of blood.

v) Vaginal examination is avoided as it provokes bleeding.

7) Confirmation of diagnosis-

a) Painless recurrent vaginal bleeding in second half of pregnancy.

b) USG.

c) MRI.

8) Complication of placenta previa-

a) Maternal and fetal morbidity and mortality.

b) Maternal-

i) During Pregnancy-(DAMP)

- Death due to hemorrhage.

- APH with Shock.

- Malpresentation.

- Premature labour.

ii) During labour-(SPICE)

- Slow dilation of cervix.

- Placenta retained, Postpartem hemorrhage.

- Intrapartum hemorrhage.

- Cord prolopse.

- Early rupture of membrane.

iii) Puerperium-

- Sepsis.

- Subinvolution.

- Embolism.

c) Fetal-(ABCD)

i) Asphyxia.

ii) Birth injuries.

iii) Congenital malformation.

iv) Death.

v) LBW.

9) Management-

a) Prevention-

i) Regular antenatal care.

ii) Antenatal diagnosis.

iii) USG.

iv) MRI.

b) Treatment-

i) Treatment outside hospital-

- Put patient on bed.

- Note Pulse, BP, temperature and amount of PV bleeding.

- Give mild sedation.

- Start IV drip.

- Vulval inspection is done.

- Mechanism for spontaneous control of bleeding-

> Thrombosis of open sinuses.

> Mechanical pressure.

> Placental infarction.

ii) Further management in hospital-

- If PV stops-

> Complete bed rest.

> Haematinics or blood transfusion to treat anemia.

> Observation of FHS.

> PV examination.

> USG

- If PV continues-

> LSCS.

> Termination of pregnancy.

Types of Placenta Previa