I- INTRODUCTION-DEFINITION :
that & rsquo we said, is a placenta previa when & rsquo; s it & rsquo; wholly or partially inserted on the lower segment The frequency of the ulcerative placenta previa is 0.28% pregnancy
II- ETIOLOGY :
A- AVERAGING PLACENTA ON SEGMENT LOWER :
The placenta is overflowing on the lower segment to increase the surface d & rsquo; maternal-fetal exchanges due to multiple pregnancies, Advanced maternal age, smoking and drug abuse.
B- LOW implantation PRIMITIVE :
- uterine abnormalities (uterine malformations, fibroma, adenomyosis…)
- Assisted reproduction
- Endometrial weakened by multiparity, endometritis, Caesarean scar, ATCD d & rsquo; abortion, récidive of PP
III- ANATOMICAL CLASSIFICATION :
There are four stages in the classification MacAfee
- Stage IV : Total central placenta praevia or : covering entirely the & rsquo; internal cervical os
- Stage III : PP part where only a portion of the neck is covered by the placenta
- Stage II : PP marginal here affleure the & rsquo; internal cervical orifice
- Stage I : PP side whose lower edge remains at a distance due the & rsquo; internal cervical os < 5cm
IV- PATHOLOGICAL ANATOMY :
A- MACROSCOPIE :
The PP is generally more spread out and thinner than normal placenta, it shows a small side of the membranes, at this level of villous degeneration zones (fibrin)
In case of fetal death : the placenta shows a decrease 30% placental weight with hematoma associated with death
B- MICROSCOPY FOR DEATH FETAL :
necrosis decidua, Marginal thrombosis with stromal fibrosis detached placental tongue
V- PATHOPHYSIOLOGY :
- During pregnancy bleeding occurs during uterine contractions that cause a tugging on the lower edge of the placenta
- When working : I cervical dilatation causes detachment of the placenta
- L & rsquo; origin of the bleeding is dual maternal and fetal
WE- CLINICAL STUDY :
A- FUNCTIONAL SIGNS :
- L & rsquo; hemorrhage : made of red blood, franc, appear spontaneously or at the & rsquo; uterine contraction during physical exertion or. It is often recurrent.
- The pain kind of uterine contractions
B- GENERAL SIGNS :
Pallor, rapid pulse, low TA.
C- PHYSICAL SIGNS :
- Palpation : flexible uterus outside contraction, with high and mobile presentation
- Auscultation : BCF good or altered
- Examination under speculum : checks the & rsquo; origin endo-uterine bleeding
- Televisions : cervical intra looking placental mattress is formally against indicated
VII- ADDITIONAL TESTS :
A- BIOLOGY :
- GR HR and NFS
- Results of the blood erase : TP, fibrinogen, soluble complexes, PDF and D.dimères
- Search fetal red blood cells by the Kleihauer
B- cardiotocographic REGISTRATION :
- Highlights uterine contractions with normal fetal heart rate
- Signs of suffering in case of & rsquo; maternal shock (fetal tachycardia, restricted or late decelerations oscillations)
C- ULTRASOUND :
For abdominal and vaginal way above : allows the diagnosis of placenta previa and to classify as classified by BESSIS :
- Placenta praevia Antérieur :
– Type 1 : not exceeding the upper third of the bladder
– Type 2 : between the 1/3 and 2/3 upper bladder
– Type 3 : flush with the collar
– Type 4 : is located at 4cm back of the neck
- Placenta praevia postérieur :
– Type 1 : is located at 4 cm back of the neck
– Type 2 : flush with the collar
– Type 3 : reached the lower third of the bladder
– Type 4 : exceeds the lower third of the bladder
VIII- EVOLUTION- COMPLICATION :
In the absence of treatment : maternal mortality is 25 for miles case (disorders & rsquo; hemostasis, anemia, endometritis, accident thrombo embolique, renal failure, or pituitary necrosis syndrome SHEEHAN)
Fetal mortality is 90% ; it is linked to prematurity, RCIU, especially heart defects)
When Active Management, l & rsquo; evolution marked by PP :
- The rebleeding
- RPM risk with chorioamnionitis or prolapsed cord
- Premature delivery
IX- CLINICAL FORMS :
- asymptomatic
- early form of 1is and 2th trimester
- Forms associated :
– and HRP
– placenta accreta
– Out d & rsquo; a vessel previa (vasa praevia)
X- DIAGNOSTIC DIFFERECIEL :
- Any extra genital bleeding (hemorrhagic cystitis, anal fissure or haemorrhoids)
- vulval bleeding, vaginal or cervical
- During the 2th trimester : basal decidual hematoma, late ABRT, or hydatidiform mole
- During the 3th trimester : decidual or marginal hematoma, uterine rupture, placenta circumvallata, Intra uterine melaena.
XI- TREATMENT :
- Hospitalization in the presence of & rsquo; a multidisciplinary team (obstetrician, anesthetist, pediatrician)
- maternal resuscitation : two broad ways d & rsquo; first, decubitus left lateral, oxygen 6 81 / m transfusion & rsquo; albumin, PFC, blood group iso iso rhesus
- Conservative treatment :
– Toccolyse : antagonists to the & rsquo; oxytocin (atosiban*), AINS, (3against mimetic indicated if bleeding PP
– lung maturation of corticosteroids : 12Betamethazone mg to 24 d & rsquo; interval
– Prevention of & rsquo; allo immunization HR
- treatment obstetrical :
– caesarean : if emergency : massive hemorrhage with & rsquo; admission or not responding to treatment, or if the presence of signs of fetal distress
Outside of & rsquo; if PP covering emergency or pathological presentation
– low life : PP non-overlapping with cephalic presentation, artificial rupture of membranes early is advised with strict monitoring of BCF, natural or placenta, infusion & rsquo; oxytocic maintained in the puerperium.
XII- CONCLUSION :
If placenta previa, Perinatal mortality has decreased significantly due to the prolongation of pregnancy, l & rsquo; extraction by caesarean, Prenatal steroids and neonatal resuscitation
Maternal mortality has decreased considerably due to blood transfusions and & rsquo; extraction by caesarean.
Course of Dr A. ABSURD – Faculty of Constantine
