PLACENTA PREVIA

                                          

    

What is Placenta Previa ?

The term previa means in front of.
It denotes the position of placenta in relation to presenting part.

Definition :
“It is defined as the condition in which the placenta is implanted partially or completely over the lower uterine segment [over & adjacent to internal os].”

Etiology & Risk factors:

• Age
• Multiparity
• Dropping down theory
• Multiple gestation
• Smoking or Alcoholism
• Defective decidua
• Scar on uterine wall

Degrees of Placenta Previa:
•First degree/type I [low lying placenta or placental lateralis]: Major part of placenta is attached at upper segment but lower placental edge does not reache the internal os besides being at lower uterine segment.

 
•Second degree/type II [placenta previa marginalis]: the placenta reaches the margin of internal os but does not cover it. 

•Third degree/type III [Incomplete centralis]:
The placenta covers the internal os when it is closed or partially dilated but not when it is fully dilated.

•Fourth degree/type IV [Complete centralis]: the placenta covers the internal os when the cervix is fully dilated.

Sign & symptoms :

• The only symptom of placenta previa is vaginal bleeding
• Secondary symptoms are due to bleeding :
• Hypotension
• Shock
• Hypovolemia
• Delirium
• Respiratory distress
• Asphyxia neonatrum to the fetus

Mechanism of bleeding:
Dilatation of lower uterine segment caused by retardation of placental growth in later months of gestation causing shearing of placenta from uterine wall leading to opening of uteroplacental blood vessels ending in episoded of bleeding

Medical & Nursing Management:
Immediate Mgt-

• Assessment of amount of blood loss
• IV infusion of NS or RL to be started
• Provision of blood transfusion to be made
• Resuscitation if needed

Conservative treatment:

• This is to be opted when the mother is not in labour
• Provison of contuinuing pregnancy until 36 weeks is to be made by 
• Complete bed rest following hospital admission
• Complete observation of patient until delivery
• Correct anemia & observe fetal well being
• Administer anti-D immunoglobulin for Rh negative mothers

If the mother is in labour:

• Assessment of the condition & selection of either NVD or LSCS

NVD:

• All possible steps to be taken to restore blood volume
• Oxytocin 10 units IV/IM ,methergin 0.2 mg should be given
• Proper examination of cervix should be done to detect evidence of tear
• Hemoglobin level of baby to be checked & if necessary arrangements of blood transfusion is made

LSCS:
It is to be performed if following conditions persist:

• Placenta previa centralis
• Placenta previa marginalis posterior
• Severe bleeding
• Presentation other than vertex
• Contracted pelvis
• Cord prolapse
• Vasa previa

Distinctive facts:

• Ix:  Visualization of bright red blood per vaginally, USG is the method of choice
• PV examination is to be avoided or to be done with all equipments ready for delivery
• Coitus needs to be avoided as it can provoke the placental separation
• NVD is usually done by Amniotomy+ Oxytocin.
• Placenta Previa Marginalis is also called as dangerous placenta previa
• Complications include :APH, PPH, Fetal asphyxia, IUD

Prognosis:

MMR is < 1% if appropriate & timely management is seeked.

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