Antepartum Haemorrhage Flashcards
What is antepartum haemorrhage?
Bleeding from the genital tract after 24 weeks gestation
What is placenta praevia?
when the placenta is implanted in the lower segment of the uterus
How does placenta praaevia differ from ‘low lying placenta’
Low-lying placenta is used when the placenta is within 20mm of the internal cervical os
Placenta praevia is used only when the placenta is over the internal cervical os
How is placenta praevia classified?
Minor - placenta in lower segment (not over os)
Major - placental completely or partially covering os
In what circumstances is placenta praevia more common in?
Previous caesarean sections Previous placenta praevia Older maternal age Maternal smoking Structural uterine abnormalities (e.g. fibroids) Assisted reproduction (e.g. IVF)
What are the effects of placenta praevia?
Antepartum haemorrhage Emergency caesarean section Emergency hysterectomy Maternal anaemia and transfusions Preterm birth and low birth weight Stillbirth
What is the effect of placenta implanting in a previous C-section scar?
it may b so deep as to prevent placental separation (placenta accreta) or penetrate through the uterine wall into surrounding structures such as the bladder (placenta percreta)
Who does placenta accreta occur in?
Previous placenta accreta Previous endometrial curettage procedures (e.g. for miscarriage or abortion) Previous caesarean section Multigravida Increased maternal age Low-lying placenta or placenta praevia
What is the effect of placenta accreta?
PPH
What is the presentation of placenta praevia?
The 20-week anomaly scan is used to assess the position of the placenta and diagnose placenta praevia.
Many women with placenta praevia are asymptomatic. It may present with painless vaginal bleeding in pregnancy (antepartum haemorrhage). Bleeding usually occurs later in pregnancy (around or after 36 weeks).
What lies and engagements are common with placenta praevia?
Breech position and transverse lie are common
the foetal head is not engaged and high
How is diagnosis of placenta praevia done?
For women with a low-lying placenta or placenta praevia diagnosed in 20 week scan
32 weeks gestation
36 weeks gestation (if present on the 32-week scan, to guide decisions about delivery)
What is the management of placenta praevia?
Corticosteroids are given between 34 and 35 + 6 weeks gestation to mature the fetal lungs, given the risk of preterm delivery.
Planned delivery is considered between 36 and 37 weeks gestation. It is planned early to reduce the risk of spontaneous labour and bleeding. Planned cesarean section is required with placenta praevia and low-lying placenta (<20mm from the internal os).
Emergency caesarean section may be required with premature labour or antenatal bleeding.
What is the management if there is placenta accreta or percreta?
Anticipated and a clear plan made for elective delivery with interventional radiology and expert surgical and anaesthetic support
uterine incsion is made away from the placenta which can be left in situ or removed with the entire uterus
Partial separation or transection during uterine incision may lead to massive haemorrhage - 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
What is placental abruption?
Placental abruption refers to when the placenta separates from the wall of the uterus during pregnancy. The site of attachment can bleed extensively after the placenta separates. Placental abruption is a significant cause of antepartum haemorrhage.
What are the outcomes of placenta separating?
Considerable maternal bleeding may occur behind it - this ca have several consequences:
- Further placental separation - acute foetal distress
- Antepartum haemorrhage - tracks down between membranes and myometrium
- Blood enter the liquor or myometrium
Foetal death is common
What are the associated factors of placental abruptions
Previous placental abruption Pre-eclampsia Bleeding early in pregnancy Trauma (consider domestic violence) Multiple pregnancy Fetal growth restriction Multigravida Increased maternal age Smoking Cocaine or amphetamine use
What is the presentation of placental abruption?
Sudden onset severe abdominal pain that is continuous
Vaginal bleeding (antepartum haemorrhage)
Shock (hypotension and tachycardia)
Abnormalities on the CTG indicating fetal distress
Characteristic “woody” abdomen on palpation, suggesting a large haemorrhage
How is diagnosis of placental abruption done?
Clinical judgement - foetus monitored using CTG and uterine activity
USS used to exclude praevia and estimate foetal weight
What is the management of placental abruption?
Admission is required, as resuscitation may be required
Delivery depends on 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 and the patient closely monitored and if all symptoms settle - discharge
(but pregnancy is now high risk)
What is the major risk with placental abruption?
PPH
Abruption vs praevia - shock?
Abruption - inconsistent with external loss
Praevia - consistent with external loss
Abruption vs praevia - pain?
Abruption - common, often severe, constant with exacerbations
Praevia - no - contractions occasionally
Abruption vs praevia bleeding?
Praevia - may be absent, often dark
Abruption - red and often profuse
often smaller previous antepartum haemorrhage
Abruption vs praevia tenderness?
Abruption - usual, often severe, uterus may be hard
praevia - rare
Abruption vs praevia fetus
abruption - lie normal, often engaged, may be dead or distressed
praevia - lie ofte abnormal/head high
Abruption vs praevia ultrasound
abruption - often normal, placenta not low
praevia - low
What are the other causes of antepartum haemorrhage?
Bleeding of undetermined origin
Ruptured vasa praevia
Vasa praevia is a condition where the fetal vessels are within the fetal membranes (chorioamniotic membranes) and travel across the internal cervical os. The fetal membranes surround the amniotic cavity and developing fetus.
Uterine rupture
Bleeding of gynaecological origin
How is bleeding of undetermined origin diagnosed?
When APH is small and painless, but the placenta is not praevia
May be impossible to find a cause
When does vasa praevia occur?
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. Occurs in 1% of pregnancies
Which vessels are more likely to rupture in ruptured vasa praevia?
vessels closer to the cervix
Occurs in 1 in 5000 pregnancies - usually when the membranes rupture. massive foetal bleeding follows
What is the presentation of ruptured vasa praevia?
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
When does uterine rupture occur?
very rare
rupture can occur before labour in women with other uterine scars or a congenitally abnormal foetus
What is the managment of bleeding in pregnant women who’s smears are overdue?
undergo speculum examination and colposcopy
cervical polyps, ectropion and vaginal lacerations may be evident
