Dr . N SRAVANTHIDr . NEHA GUPTA

Dr . SEEMA CHOPRA

ANTEPARTUM HAEMORRHAGEPLACENTA PREVIA

Definition

“bleeding into or from the genital tract after 24 weeks of gestation”

“ Bleeding from the female genital tract anytime after fetal viability but before delivery”

(WHO )

Affects 3-5% of all pregnancies.

3 times more common in multiparous than primiparous women .

Classification

Causes and incidence Cause IncidencePlacenta praevia 31%Placental abruption 22%Unclassified 47%– Marginal 60%– Show 20%– Cervicitis 8%– Trauma 5%– Vulvovaginal varicosities 2%– Genital tumours 0.5%– Genital infections 0.5%– Haematuria 0.5%– Vasa praevia 0.5%– Others 0.5%

PLACENTA PRAEVIA

definitionPlacenta praevia is defined as the presence of

placental tissue over or adjacent to the cervical os.

In other words “ when part or all of the placenta in the lower uterine segment”

INCIDENCE: overall 4/1000 deliveriesIn 2nd trimester may be found in 4-6 %

pregnancies…. 0.5 to 1% term

Gabbe obstetrics 5th edition

Hypothesis for resolution of placenta praevia at termAs pregnancy advances, stationary lower placental

edge relocates away from os with development of LUS.

Trophotropism: growth of trophoblastic tissue away frm cervical os towards the fundus resulting in resolution

For a placental edge reaching or overlapping the internal os, incidence - 42% between 11 and 14 weeks, 3.9% between 20 and 24 weeks, and 1.9% at term.(Ultrasound Obstet Gynecol 2002)

Classification Type 1 (Lateral or low lying): edge of

placenta encroaches on lower segment but not upto int. os

Type 2(Marginal): lower edge extends to but not across the os

Type 3(Partial): placental edge extends assymetrically across the os but doesn’t cover it completely after cervical dilatation

Type 4(Complete or central): placenta placed over the os and likely to cover even after full cervical dilatation

etiology/risk factorsIncreasing parity

Grand multiparas 5%risk Nulliparous women 0.2% risk

Increasing maternal age >35 years 4 fold increased risk >40 years 9 fold increased risk

Cigarette smokingResidence at higher altitudesMultiple gestationsPrevious placenta praeviaPrior curettagePrior cesarean delivery

Clinical manifestationsTypical presentation : painless vaginal

bleeding.Post coital bleedingRecurrent bleedingMalpresentationUnstable lieHigh presenting part

DIAGNOSIS (TAS Vs TVS)26-60% of women who undergo (TAS) may

have a reclassification of placental position when they undergo TVS

With TAS, there is poor visualization of the posterior placenta,the fetal head can interfere with the

visualization of thelower segment, obesity and underfilling or overfilling of the

bladder, interfere with accuracy

TAS is associated with a false positive rate for the diagnosis of placenta previa of up to 25%

Accuracy rates for TVS are high sensitivity 87.5%, specificity 98.8%, positive predictive value 93.3%, Negative predictive value97.6%

safe in the presence of placenta praevia, even when there is established vaginal bleeding

SOGC CLINICAL PRACTICE GUIDELINE No. 189, March 2007

Translabial/Transperineal USSuperior to abdominal views in both

diagnosis and exclusionAffords a quick , accurate and well tolerated

view of cervix to ascertain length and placental localisation relative to internal osImproved spatial and contrast resolution Less interposed soft tissues and diminished

accoustic attenuation

ROLE OF MRIaccurately image the placenta and is superior

to TASunlikely that it confers any benefit over TVS

for placental localizationNot readily available

SOGC CLINICAL PRACTICE GUIDELINENo. 189, March 2007

Transabdominal ultrasound of a low-lying placenta. The lower edge of the placenta is 18 mm away from the endoncervix (callipers)

Transvaginal ultrasound of a complete placenta previa that appears to be central (asterisk–placenta; arrows–endocervical canal).

Transvaginal ultrasound of a complete placenta previa that is not central 

Transvaginal sonogram in the second trimester demonstrating form of placenta praevia. In this case, the inferior placental edge is shown to encroach upon the posterior cervix but not reach or cover the internal cervical os (arrow).

 Example of incomplete previa demonstrated by transvaginal ultrasound. In this case, the inferior placental edge (Pl) extends onto the cervix posteriorly and is located approximately 1 cm from the internal cervical os (arrow).

Transvaginal sonography Reporting of the actual distance from the placental

edge to the internal cervical os in milimeters or in mm of overlap

 placental edge exactly reaching the internal os is described as 0 mm

between 18 and 24 weeks‘ gestation (incidence 2 to 4%)

If overlap >15mm increased likelihood of placenta praevia at term

 a follow-up examination for placental location in the third trimester

Between 20 mm away from the internal os and 20 mm overlap after 26 weeks' gestation,

repeated USG at regular intervals depending on the gestational age, distance from the internal os, and clinical features such as bleeding, because

continued change in placental location is likely. Overlap of 20 mm or more at any time in the

third trimester is highly predictive of the need for Caesarean section (CS)

Managementantepartum bleed

tranfer to an appropriate level hosp

assessment of vital signs and abdominal examination

NO DIGITAL PELVIC EXAMINATION/ PER SPECULUM EXAMINATION

assesment of blood loss n correction of hypovolemia, anaemia

i.v drip with crystalloid infusion

blood test: cbc, blood type n antibody screen,coagulation profile, platelets count,

at least 2 units of blood cross matched

placental losalisation by ultrasound

management acc to clinical circumstances

MANAGEMENTExpectant Management of Patients remote from termPatients with placenta praevia who present

preterm with vaginal bleeding

hospitalization and immediate evaluation to assess maternal-fetal stability.

should initially be managed in a labor and delivery unit with continuous fetal heart rate and contraction monitoring

 Large-bore intravenous access and baseline laboratory studies (hemoglobin, hematocrit, platelet count, blood type and screen, and coagulation studies) should be obtained.

IF <34 WKS : Administer antenatal corticosteroidsTocolysis : If the vaginal bleeding is preceded by or associated with uterine contractions.

Role of cervical encirclageIn one study, there was a reduction in the risk

of delivery before 34 weeks or the birth of less than 2000g

There is insufficient evidence to recommend the practice of cervical cerclage to reduce bleeding in placenta praevia.

RCOG 2011

Outpatient management of placenta previa may be appropriate for stable women with home support, Close proximity to a hospital, and readily available transportation and telephone

communication.

RCOG 2011

OUTPATIENT MANAGEMENT IN PLACENTA PRAEVIA

CONSERVATIVE MANAGEMENT<37 weekspatient not in labour, Patient hemodynamically stableNo fetal distress or malformations

•admit the patient •usg confirmed placenta praevia-• matched blood be available all the times•anemia to be treated•if gestation <34 antenatal corticosteroids•if Rh negative – anti D should be given

as preg. progresses (usg assessmnt of fetal growth n well

being)

ACTIVE management at

37 – 38weeks

Route of delivery at term

The os–placental edge distance on TVS after 35 weeks' valuable in planning route of delivery.

> 20 mm away from the internal cervical os, can be offered a trial of labour .

A distance of 20 to 0 mm away from the os - higher CS rate

Any degree of overlap (> 0 mm) after 35 weeks is an indication for Caesarean section for delivery.

Caeseraen section in placenta praevia(technical considerations)Pfannensteil incision adequate in most

situations If placenta anterior- best not to cut through

the placenta

Best to use hand to separate placenta to the nearest edge

Rupture the membranes, deliver the baby n promptly clamp the cord

The site of placental implantation in non-contractile LUS may continue to ooze can cause alarming bleeding

Other options : Ballon tamponade, Uterine and ovarian artery ligation, Full thickness horizontal or square compression sutures

If above procedures fail -> ligation of anterior division of int. illiac artery

T/t - pressure packing of the LUS for 4 minuteDicrete points of bleeding identified n oversewn by figure of eight

METHOD OF ANAESTHESIA FOR CAESAREAN SECTIONRegional anaesthesia is safe

When prolonged surgery is anticipated in women with prenatally diagnosed placenta accreta , general anaesthesia may be preferable

Regional anaesthesia could be converted to general anaesthesia if undiagnosed accreta is encountered

SOGC CLINICAL PRACTICE GUIDELINE No. 189, March 2007

THANK YOU