Antepartum haemorrhage

Question 1

What is the definition of antepartum haemorrhage?

Answer 1

bleeding from the genital tract after 24 weeks’ gestation

Question 2

What is placenta praevia?

Answer 2

placenta is implanted in the lower segment of the uterus- complicated 0.4% of pregnancies at term
• At 20 weeks the placenta is ‘low-lying’ in many pregnancies, but appears to move upwards as the pregnancy continues this is due to the formation of the lower segment of the uterus in the 3rd trimester, the myometrium where the placenta is implanted moves away from the internal cervical os,

Question 3

How is placenta praevia classified?

Answer 3

according to the promixity of the placenta to the internal os
Marginal (types I-III): placenta in lower segment not over os
Major (types III-IV): placenta completely or partially covering os

Question 4

What is the aetiology of placenta praevia?

Answer 4

More common in 
o	Twins
o	High parity
o	Increased maternal age
o	Scarred uterus

Question 5

Why can haemorrhage be severe in placenta praevia?

Answer 5

may continue during and after delivery as the lower segment is less able to contract and constrict the maternal blood supply

Question 6

What occurs if the placenta implants in a previous c-section scar?

Answer 6

it may be so deep as to prevent placental separation (placenta accreta) or penetratre through the uterine wall into surrounding structures, such as the bladder (placenta percreta), placenta accreta occurs in 10% of women who have both a placenta praevia and a single previous C-section this may provoke massive haemorrhage at delivery and often requires a hysterectomy

Question 7

How does placenta praevia present?

Answer 7

intermittent painless bleeds, which increase in frequency and intensity over several weeks
⅓ of women have not experienced bleeding before delivery
• Breech position and transverse lie are common, the foetal head is not engaged and high
vaginal exam is never performed unless placenta praevia has been excluded

Question 8

How is placenta praevia diagnosed?

Answer 8

USS- low-lying placenta is detected at 2nd trimester scan, then it is repeated at 32 weeks to exclude placenta praevia (vaginally if placenta posterior)
• Where presentation is with bleeding- CTG, FBC, clotting and cross-match are completed, foetal distress is uncommon

Question 9

What is the management for placenta praevia?

Answer 9

• Women is admitted if bleeding from a placenta praevia- steroids administered in <34 weeks
• Delivery is by elective C-section at 39 weeks
• Placenta accreta or percreta should have been anticipated and a clear plan made for elective delivery with interventional radiology and expert surgical & anaesthetic support
treatment involves compression of the inside of the scar after removal of the placenta with an inflatable balloon, excision of the affected uterine segment or frequently total hysterectomy

Question 10

What is placenta abruption ?

Answer 10

part (or all) of the placenta separates before delivery of the foetus
1% of pregnancies
however, it is likely that many antepartum haemorrhages of ‘undetermined origin’ are small placenta abruptions

Question 11

What are the consequences of placenta abruption?

Answer 11

considerable maternal bleeding
o Further placental separation- acute foetal distress
o Antepartum haemorrhage- tracks down between membranes and myometrium
o Blood enter the liquor or myometrium
• Foetal death is common- 30% of proven abruptions, haemorrhage often necessitates blood transfusion, this DIC and renal failure may lead to maternal death

Question 12

What are the risk factors for placenta abruptions?

Answer 12

o	IUGR
o	Pre-eclampsia
o	Autoimmune disease
o	Maternal smoking
o	Cocaine usage
o	Previous history of placental abruption- risk 6%
 o	Multiple pregnancy
o	High maternal parity
o	Trauma
o	Sudden reduction in uterine volume (membrane rupture)

Question 13

How does placenta abruption present?

Answer 13

painful bleeding- pain due to blood behind the placenta and in myometrium, blood is often dark, degree of vaginal bleeding does not reflect severity of bleeding
• Tachycardia suggests profound blood loss- hypotension only occurs after massive blood loss, the uterus is tender and often contracting, so labour ensues- foetal tones are often abnormal or even absent

Question 14

How is placenta abruption diagnosed?

Answer 14

Clinical judgement
foetus monitored using CTG and uterine activity
USS used to exclude praevia and estimate foetal weight, ICU for mother may be necessary

Question 15

What is the management for placenta abruption?

Answer 15

• Admission is required, as resuscitation may be required, delivery depends of foetal state and gestation – if foetal distress then emergency C-section, but if not then labour is induced with amniotomy
• If no foetal distress, the pregnancy is preterm and the degree of abruption is minor, then steroids can be given, patient closely monitored and if all symptoms settle discharged pregnancy is now ‘high risk’
• Whatever the mode of delivery- postpartum haemorrhage is a major risk

Question 16

What are the features of placenta abruption?

Answer 16

Shock: inconsistent with external loss
Pain: common and often severe, constant with exacerbations
Bleeding: may be absent, often dark
Tenderness: Usual, often severe, uterus may be hard
Fetus: Lie normal, often engaged. May be dead or distressed
USS: often normal placenta not low

Question 17

What are the features of placenta praevia?

Answer 17

Shock: consistent with external loss
Pain: no, contractions occasionally 
Bleeding: red and often profuse. Often smaller previous APH
Tenderness: rare 
Fetus: lie often abnormal/head high 
USS: placenta low

Question 18

What is ruptured vasa praevia?

Answer 18

• Vasa praevia occurs when a foetal blood vessel runs in the membranes in front of the presenting part
these vessels usually result from the umbilical cord being attached to the membranes rather than the placenta (velamentous insertion) or where the placenta is in parts
• Rupture is more likely with vessels closer to the cervix- membranes rupture, massive foetal bleeding follows

Question 19

How does ruptured vasa praevia present?

Answer 19

• Typical presentation is painless, moderate vaginal bleeding at rupture of the membranes, which is accompanied by severe foetal distress
C-section is often not fast enough to save the foetus

Question 20

What is a uterine rupture?

Answer 20

• Significant antenatal rupture of a lower segment C-section scar is very rare very occasionally rupture occurs before labour in women with other uterine scars or a congenitally abnormal uterus

Question 21

What causes bleeding of gynaecological origin?

Answer 21

• Cervical CA can present in pregnancy- if a cervical smear is overdue, the women with small recurrent or postcoital haemorrhage should undergo speculum examination and colposcopy
• Cervical polyps, ectropions and vaginal lacerations may also be evident, but bleeding should not usually be attributed to them