bleeding from the genital tract after 24 weeks gestation
name 3 common causes of APH
1. undetermined origin
2. placental abruption
3. placenta praevia
name 3 rare causes of APH
1. incidental genital tract pathology
2. uterine rupture (mainly in CS/scared uterus)
3. vasa praevia
what is placenta praevia?
placenta implanted in the lower segment of the uterus
why can low lying placentas appear to 'move' upwards as a pregnancy continues?
due to formation of the lower segment of the uterus in the third trimesters
myometrium where the placenta implants moves away from the internal cervical os
what proportion of placenta which are low lying at 20 weeks are praevia at term?
what is the classification of placenta praevia?
marginal: placenta in lower segment, NOT over os
major: placenta completely or partially COVERING OS
name 4 risk factors for placenta praevia
scarred uterus - previous CS
women of high parity
what are the complications of placenta praevia?
1. OBSTRUCTION : placenta in the lower segment obstructs engagement of the head
2. so need for C-SECTION
3. low placenta may cause lie to be TRANSVERSE
4. HAEMORRHAGE: severe, continue during and after delivery as lower segment is less able to contract and constrict maternal blood supply (remember lower uterus 90% connective tissue; 10% muscle)
5. PLACENTA ACCRETA: prevent placental separation
6. PLACENTA PERCRETA: accrete and percreta may provoke MASSIVE HAEMORRHAGE AT DELIVERY
what is placenta accrete?
placenta implants in a previous c-section scar, may be so deep as to PREVENT PLACENTAL SEPARATION
what is placenta percreta?
placenta penetrates through uterine wall into surrounding structures eg bladder
if there is massive haemorrhage due to placenta accrete or percreta, what may need to be done?
what is a typical history of placenta praevia?
intermittent painless bleeds
which increase in frequency and intensity over weeks
bleeding can be catastrophic
what may you find OE of placenta praevia?
1. breech presentation
2. transverse lie
3. fetal head is not engaged, and is high
4. vaginal examination can provoke massive bleeding and is never performed in a woman who is bleeding vaginally unless praevia has been excluded
what are 3 ways that placenta praevia can present?
1. finding on USS
2. vaginal bleeding
3. abnormal lie: breech or transverse
how is the diagnosis of placenta praevia made?
which other investigations should be done in placenta praevia?
to assess maternal and fetal well being
3. clotting study
4. cross match
what is the first step in any patient with placenta praevia and bleeding?
until delivery because of risk of massive haemorrhage
what is the management before delivery of a pt with placenta praevia
2. blood cross matched and available
3. if Rh D-ve, give antiD
4. iv access maintained
5. give steroids if gestation is < 34 weeks
if a patient has placenta praevia but is asymptomatic, what is their initial management before delivery?
delay admission until 37 weeks, as long as they can get to hospital easily
how do you delivery a baby in a lady with placenta praevia?
elective c-section at 39 weeks by the most senior person available
what are the complications at delivery in placenta praevia?
PPH as lower segment of uterus does not contract well after delivery and that is where placenta is so bad!
when in placenta praevia can vaginal delivery be contemplated?
if the degree of praevia is marginal and fetal head is past the lower edge on ultrasound
only do VE in theatre with full facilities for immediate C-section
what is the treatment of placenta accrete?
compression of the inside of the scar after removal of the placenta with an inflatable balloon
what is placental abruption?
when part or all of placenta separates before delivery of fetus
what % of pregnancies does abruption occur?
when you get part of placenta separating, what happens?
1. maternal bleeding behind it
2. further separation and acute fetal distress
3. blood tracks down between the membranes and myometrium to come our and be revealed as APH
4. blood may enter liquor
5. blood may simply enter myometrium and there is no visible haemorrhage
what % of abruption is there no visible haemorrhage?
name 5 complications of abruption
1. fetal death is common
2. haemorrhage to need blood transfusion
4. renal failure
5. ultimately maternal death
what are the risk factors for placental abruption? split into 4 categories
1. fetal: IUGR, multiple pregnancy
2. maternal current: pre-eclampsia
3. maternal past: previous abruption, high parity
4. social: smoking, cocaine usage
what has abruption been associated with?
sudden reduction in uterine volume: eg ROM in polyhydramnios
what is the bleeding in abruption like compared to praevia?
PAINFUL: due to blood behind placenta and in myometrium
CONSTANT - with exacerbations
how does the degree of vaginal bleeding reflect the severity of the abruption?
it DOES NOT reflect severity of abruption because some blood may not escape from the uterus
if you get pain alone but are suspecting abruption, what is that called? and what are signs OE of that?
tachycardia out of proportion to vaginal loss
if you get vaginal bleeding in abruption, what is that called?
name 2 major symptoms of placental abruption
what are the signs OE of placental abruption?
tender, woody hard uterus (often contracting)
fetal distress or absent heart sounds
how is a diagnosis of abruption made?
Ix help to assess severity and plan resuscitation and delivery
how is fetal wellbeing established?
what are the signs of abruption on CTG
frequent uterine activity
what 3 tests are done to establish maternal well being in suspected abruption
what role does USS have in suspected abruption?
rule out praevia.
otherwise not much help
what are the classical signs of abruption
PV bleed - may or may not if concealed
uterine tenderness - woody hard
what is the immediate management of abruption?
steroids if gestation < 34 weeks
blood transfusion may be needed
antiD to Rh -ve women
how do you deliver a baby in suspected abruption? what does it depend on?
first stabilise mother
depends on FETAL DISTRESS
if fetal distress, urgent delivery by c-section needed
if no fettle distress but gestation is 37+ do IOL with amniotomy
if the fetes is dead, coagulopathy is likely. blood products are given and labour is induced
if no fettle distress and PRETERM pregnancy, and degree of abruption is MINOR then give steroids if <34 weeks and monitor closely on antenatal ward. if symptoms settle, discharge but now high risk pregnancy and need fettle growth USS
what is a major risk to the mother after the baby is born?
post partum haemorrhage
what is vasa praevia?
when a fettle blood vessel runs in the membranes in front of the presenting part eg head or bum if breech
when do you get vasa praevia?
when umbilical cord is attached to the MEMBRANES rather than the placenta
= velamentous insertion
when happens when you got ROM in vasa praevia?
massive fettle bleeding
what is typical presentation of vasa praevia?
moderate vaginal bleeding at amniotomy or SROM
in uterine rupture what kind of bleeding predominates?