Case 17 A 34-year-old woman with painless vaginal bleeding at 33 weeks’ gestation

Case 17 A 34-year-old woman with painless

vaginal bleeding at 33 weeks’

gestation

Mrs Chou, a 34-year-old woman in her third pregnancy,

presents to the maternity day assessment unit with a history

of bleeding per vaginum (PV) about an hour prior to

presentation. She is 33 weeks’ pregnant.

What differential diagnoses would

you consider as a cause for the

antepartum haemorrhage?

• Placenta praevia

• Placental abruption

• Local (cervical, vaginal) causes

• Preterm labour

• Bleeding of uncertain origin

small amount, about two teaspoonfuls. She has been feeling

the baby move well, and there has been no change in fetal

movements from previously. There is no history of

intercourse over the last week.

What other relevant information would

you wish to obtain?

• Obstetric details of her last two pregnancies:

gestation at delivery (term or preterm)

mode of delivery (vaginal or caesarean section)

any complications (e.g. APH, premature rupture of

membranes)

• Has she been up to date with her cervical smears?

• What is her blood group?

Mrs Chou’s first delivery was 4 years ago when she had an

elective caesarean section at 39 weeks for the indication of

a breech presentation. There had been no other antenatal

complications, and her daughter weighed 3250g at birth.

Her last pregnancy had been 2 years ago when she had

an emergency caesarean section at 41 weeks for the

indication of slow progress in labour. There had been no

particular problems antenatally and she had gone into

labour spontaneously. Her son weighed 3500g at birth and

was well. She had made a good postoperative recovery after

both caesarean sections.

Mrs Chou was up to date with her cervical smears and

had her last smear a year ago. All her smears to date have

been negative.

Her blood group is O-negative. She received anti-D

immunoglobulin antenatally and postnatally in both her

previous pregnancies. She was administered prophylactic

anti-D in this pregnancy at 28 weeks’ gestation.

What features would you look for in

your examination?

• Does she look distressed or in pain?

• Any signs of pallor, pulse and blood pressure recordings

Obstetrics and Gynaecology: Clinical Cases Uncovered.

By M. Cruickshank and A. Shetty. Published 2009 by Blackwell

Publishing. ISBN 978-1-4051-8671-1.

KEY POINT

Antepartum haemorrhage (APH) is defined as bleeding

from the genital tract after about 24 weeks’ gestation and

is seen in 3–5% of pregnancies. About half of cases turn

out to be bleeding of unknown origin after the other

causes listed above are ruled out with appropriate

investigation and examination.

What specific questions would you wish

to ask about her presenting symptoms?

• Has there been any abdominal pain?

• How much has she bled? Has it been fresh bleeding?

Any clots? Any fluid leaking PV?

• Has she been feeling the baby move?

• Is this the first episode of bleeding?

• Did she have sexual intercourse prior to the bleed?

Mrs Chou says that there has been no pain. This was the

first episode of bleeding. The bleeding has been fresh, but aCase 17 117

PART 2: CASES

• On abdominal palpation:

any tenderness

uterine tone and contractions

• Lie and presentation of the baby

• Doppler fetal heart check

• Check pads or undergarments stained with blood that

the patient may have brought in, or for any signs of

bleeding down her legs.

Mrs Chou appears comfortable. There is no obvious pallor,

her pulse is 86beats/minute and BP 130/76mmHg. There is

no tenderness on abdominal palpation, and the uterus is

soft with no contractions. The baby is in the transverse

position. The fetal heart is regular at around 140beats/

minute. She is wearing a pad stained with a small amount

of fresh blood.

What would be your most likely

differential diagnoses based on the

history and examination?

Placenta praevia.

KEY POINT

Placenta praevia must be considered in pateints with

painless APH. Other pointers or risk factors to consider in

the diagnosis of placenta praevia:

• Previous caesarean section (especially multiple caesarean

sections)

• Fetal malpresentation or abnormal lie in the third

trimester

• Previous history of placenta praevia

• Multiple pregnancy

• Increasing age and parity

• Placenta noted to be lying over the internal os at routine

mid-trimester fetal anomaly scan

What would you do next?

• Fetal cardiotocography (CTG) to check fetal well - being

• Arrange an ultrasound scan for placental localization

• Kleihauer test and anti - D immunoglobulin as required

• Avoid vaginal examination.

The CTG is reassuring. The scan suggests a major anterior

placenta praevia (grade III – placenta just extending over the

cervical internal os; Box 17.1; Figs 17.1 & 17.2).

Box 17.1 Grades of placenta praevia as

diagnosed on ultrasound

Grade I The placenta encroaches into the lower uterine

segment (within 5cm of the internal os)

Grade II The lower edge of the placenta reaches but

does not cover the internal os

Grade III The placenta covers the internal os partially

Grade IV The placenta is centrally located over the

internal os

Grade I and II are classified as ‘minor’ and grades III and IV

as ‘major’ placenta praevia. The incidence of morbidity and

mortality in the fetus and mother increases as the grade

increases.

Grade II Grade IV Grade III

Figure 17.1 Grades of placenta praevia.

!RED FLAG

Avoid vaginal examination until the scan confirms that the

placenta is not low lying. If placenta praevia is confirmed,

avoid vaginal examination as it may trigger a torrential

vaginal bleed.

Pain associated with APH should alert the clinician to

a placental abruption or preterm labour (see Cases 18

and 19 ). In about 10% of women, placental abruption

can occur with a low lying placenta and the two conditions can be present together.

If placenta praevia is ruled out on the scan, a speculum

examination to visualize the cervix to look for lesions on

the cervix (e.g. ectropin, polyp or, rarely, a malignancy)

should be performed.

When the placenta is situated on the posterior wall of

the uterus, transabdominal sonography may not be able

to establish the grade of praevia adequately, especially if

the patient is obese or the bladder is overdistended.118 Part 2: Cases

PART 2: CASES

There is no further bleeding. The mother’s vital signs remain

stable and fetal CTG remains reassuring.

What would be your management

plan now?

Carry out expectant management until fetal maturity.

Then plan for elective caesarean section at around 37 – 38

weeks if the placenta remains low lying.

Consider steroids for fetal lung maturity in case the

bleeding becomes heavy, with fetal or maternal compromise, and delivery has to be considered before 36 weeks.

Carry out serial scans every 2 – 4 weeks to check if praevia

resolves as the uterus grows and lower segment increases.

Group and save sample available at blood transfusion

service at all times (preferably cross - matched blood if

available). Discuss blood transfusion with the patient in

the event of heavy bleeding. Give haematinics to maintain a normal haemoglobin.

Mrs Chou has two further small APHs and she remains in

hospital. Scans at 35 and 37 weeks confirm that the

placenta remains low grade III anterior. Her elective

caesarean section is planned for 38 weeks’ gestation. Scans

do not suggest a placenta accrete or percreta.

Vaginal delivery may be considered in women where

the placental edge is ≥2 cm from the internal os and the

fetal head is below the placenta edge as seen on the scan.

RCOG guidelines (2005) advise that women with

major placenta praevia who have bled should be admitted and managed as inpatients. ‘ Those with major praevia

who remain asymptomatic, require careful counselling

before contemplating outpatient care. Any home based

care requires close proximity with the hospital (can get

into hospital within about 20 minutes), the constant

presence of a companion and full informed consent from

the women. ’

Even with minor praevia, if there are repeated episodes

of PV bleeding, inpatient care may be recommended.

What might you discuss with her

regarding the caesarean section?

There is an increased risk of bleeding at caesarean section

for placenta praevia. Blood transfusion should be rediscussed. In view of the two previous caesarean scars and

the placenta being situated anteriorly and over the old

scars, there remains the risk of the placenta being

Figure 17.2 Posterior placenta praevia on transvaginal scan.

Transvaginal sonography may be required in these cases.

There is no evidence that a gentle transvaginal scan triggers a vaginal bleed.

When placenta praevia is diagnosed with a history of

previous caesarean section, an attempt must be made to

look for scan features of placenta accreta or percreta. This

includes indentifying a clear plane between the uterine

wall and the placental bed. MRI imaging may also facilitate the diagnosis.

What features would you consider in

making a management plan?

• Is there any further bleeding and if so, is it heavy?

• Are there any features of maternal or fetal

compromise?

• What is the gestation?Case 17 119

PART 2: CASES

adherent, although the scans do not confirm this. An

adherent placenta increases the risk and amount of postpartum haemorrhage (PPH) and if this is not controlled

by conservative measures, a hysterectomy may be

required to control the bleeding.

Regional anaesthesia may lower the blood pressure,

which may worsen things if there is active bleeding, so a

general anaesthetic is the usual anaesthetic of choice

when bleeding is anticipated.

Mrs Chou has her lower segment caesarean section

performed electively at 38 weeks’ gestation. The placenta is

encountered on making the uterine incision and is sheared

away from the uterine wall to get to the baby. The baby is

delivered feet first as it is still in the transverse position. The

placenta is removed complete. There is increased bleeding

from the lower segment placental bed. An oxytocin bolus is

administered soon after delivery of the baby and an infusion

of oxytocin is ongoing to facilitate uterine contraction. Some

of the larger vascular areas on the lower segment are

controlled with haemostatic sutures. The bleeding is brought

under control, and the operation completed satisfactorily.

Blood loss at surgery is 2000mL.

Her haemoglobin checked on day 1 postoperatively is

9.8g/dL (preoperative level was 12.1g/L) She is given

dalteparin prophylaxis until fully mobile on day 5

postoperatively for the prevention of thrombosis (risk factors

for thrombosis include the pregnancy, surgery, increased

blood loss and prolonged hospitalization which might have

resulted in reduced mobility). She is also continued on her

haematinics with advice to continue these until her

haemoglobin is rechecked 4–6 weeks later and confirmed as

normal.

KEY POINT

Postpartum haemorrhage may occur after the separation

of a low lying placenta, owing to the inability of the lower

segment to contract efficiently and arrest bleeding from

vascular sinuses.

Previous reports on the Confidential Enquiries into

Maternal Deaths have recommended that a senior

anaesthetist and obstetrician must be available at the

caesarean section. Cross-matched blood must also be

available.

CASE REVIEW

Mrs Chou developed a major placenta praevia diagnosed

on scan at 33 weeks ’ gestation when she presented with

painless bleeding PV and a fetal malposition (transverse

lie). Her two previous caesarean sections increased her risk

of having a low lying placenta. She was managed conservatively until fetal maturity. In view of repeated APHs she

was managed as an inpatient.

Repeat scans showed the placenta to remain as a major

praevia and an elective caesarean section was planned for

38 weeks. In view of her risks of PPH at caesarean section,

a senior obstetrician and anaesthetist were present at her

surgery with cross - matched blood available. While she did

have a blood loss of 2000 mL, the surgery proceeded

without event and she made a good postoperative

recovery.

In view of this being her third caesarean section, future

deliveries would be advised through an elective caesarean

section. She would also be counselled about the increased

risks of both a low lying and an adherent placenta and

of an uncontrolled PPH that might necessitate a

hysterectomy.

When the blastocyst implants low in the uterine cavity,

placenta praevia may occur. Scarring of the uterine cavity

(e.g. from previous caesarean section) or a large placenta

(e.g. with multiple pregnancy) predispose to a placenta

that lies in the lower uterine segment.

While around 25% of placentae are seen to be low lying

at the second trimester scan, this reduces to 5% at 32 weeks

and <0.5% at term with increasing development of the

lower segment. The recurrence of placenta praevia is

approximately 2%.

There is usually some bleeding in the third trimester to

suggest a low lying placenta, along with a fetal malpresentation in one - third of women. However, in fewer than 2%,

bleeding is seen only in labour.

Antepartum or postpartum haemorrhage is the main

cause of maternal morbidity, and premature delivery the

main cause of fetal problems. Most of the episodes of APH

settle spontaneously and conservative treatment to attain

fetal maturity beyond 36 weeks may be attempted to the

extent of blood transfusions for the heavier bleeds, with

careful observation of mother and fetus.120 Part 2: Cases

PART 2: CASES

KEY POINTS

• Placenta praevia must be considered in those with

painless vaginal bleeding

• Risk factors for or associations with placenta praevia

include previous caesarean section (especially multiple

caesarean sections) and malpositions of the fetus

• Vaginal examinations must not be performed where there

is a suspicion of placenta praevia until an ultrasound scan

has ruled it out

• A transvaginal scan may provide clearer views of the

placenta in the lower segment (especially with a posterior

placenta) than a transabdominal scan

• If the bleeding settles and there is no maternal or fetal

compromise, expectant management until fetal maturity is

advised

• With grade II, III and IV placenta praevia, elective caesarean

section around 38 weeks is the preferred mode of delivery.

Vaginal delivery may be considered if the lower edge of the

placenta is 2cm or more from the internal cervical os, with

the fetal head below the placental edge

• There is the risk of PPH with a low lying placenta as the

lower segment does not contract as effectively as the

upper segment after separation of the placenta

ObGyncases (Healthcare Touch)

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