Bleeding in Late Pregnancy Flashcards
What constitutes late pregnancy?
> 24 weeks
What can cause an antepartum haemorrhage?
vasa previa placenta previa placental abruption uterine rupture cystitis haemorrhoids
How common is antepartum haemorrhage?
3-5% of pregnancies
What is an antepartum haemorrhage?
bleeding from the genital tract after 24 weeks gestation + before the end of the second stage of labour
What are the functions of the placenta?
gas transfer
metabolism/waste disposal
protective filter
hormone production - HPL
What ml of blood quantifies a minor APH?
<50ml
What ml of blood quantifies a major APH?
50-1000ml
What ml of blood quantifies a massive APH?
> 1000ml and/or shock
What is placental abruption?
separation of a normally implanted placenta - partially or totally before the birth of the foetus
What % of APHs are placental abruptions?
40%
What is the pathophysiology behind placental abruptions?
vasospasm followed by an arteriole rupture into the decidua
blood escapses into the amniotic sac of further under the placenta and into the myometrium
this cause. tonic contraction which causes pain and interrupts placental circulation
What does placental abruption result in?
couverlaire uterus - blueish appearance
What are the risk factors for placental abruption?
mostly unknown PET blunt or forceful trauma smoking/cocaine/amphetamine medical thrombophilias/renal disease/diabetes polyhydroamnios/mutliple pregnancies/pre term rupture of membranes abnormal placenta previous abruption - 10% recurrence rate
What are the symptoms of placental abruption?
continuous severe abdominal pain maternal collapse backache with posterior placenta bleeding preterm labour
What are the signs of placental abruption?
HARD WOODY TENDERNESS unwell, distressed patient, fetal parts hard to identify - heart sounds bradycardic or absent CTG shows irritable uterus preterm labour w/ heavy show
How is placental abruption managed?
resuscitate mother
assess and deliver baby
2 large bore IV access cannulas, cross match 4-6 units red packed cells
if stable - induce labour by amniotomy
if unstable - delivery by catagory 1 c/section
steroids for baby
What are maternal complications of placental abruption?
hypovolaemic shock PPH - 25% anaemia renal failure coagulopathy infection thromboembolism
What are foetal complications of placental abruption?
death - 14% hypoxia prematurity SGA growth restriction
How can placental abruption be prevented?
smoking cessation
APS - give LDA
stop drug misuse
What % of APHs are placenta previa?
20%
What is placenta previa?
placenta lies directly over the internal os
after 16weeks the term low lying placenta is used when the placental edge is less than 20mm from the internal os
How far away from the internal os is the placenta usualy?
7cm
What are the characteristics of the lower segment of the placenta?
thinner
contains less muscle fibres than the upper segment
doesnt contract in labour, it passively dilates
What are the risk factors of placenta previa?
previous placenta previa smoking c/section delivery assisted reproduction multiparty previous TOP deficient endometrium due to presence of uterine scars or endometritis
When is placenta previa screened for?
mid trimester fetal anomaly scan - 20 weeks
If placenta previa is picked up at 20 weeks, when do you re scan for it?
32 and 36 weeks
What is the best USS method for placenta previa?
transvaginal
What should you do if placenta accreta is suspected?
MRI
What are the symptoms of placenta previa?
painless bleeding - pts condition is directly proportional to the amount of bleeding
sex can trigger bleeding
What are the signs of placenta previa?
uterus soft non tender
CTG normal
presenting part high
mal presentation
What must you never do until you exclude placenta previa?
perform a digital exam
How is placenta previa diagnosed?
transvaginal USS
How do you manage placenta previa?
if unstable - ABCDE and assess baby admit to hospital if PV bleeding TEDS give steroids between 34-35+6 magnesium sulfate for neural protection - 24-32 weeks
When should you deliver a baby in placenta previa?
if history of PV bleeding = 34-36+6
if uncomplicated = 36-37+0
need cross match bloods and haemorrhage protocol
When would you do a c/section in placenta previa?
if placenta covers os or = 2cm from os
What is placenta accreta?
morbidly adherant placenta to the uterine wall
What % of placenta previas are placenta accreta?
5-10%
What is placenta increta?
placenta invading the myometrium
What is placenta pancreta?
placenta invading the bladder
What is placenta accreta associated with?
severe bleeding
PPH
ending up having a hysterectomy
How is placenta accreta managed?
prophylactic internal iliac artery baloon
cesarean hysterectomy
blood loss >3L expected
What are the risk factors for placenta accreta?
placenta previa
previous c/section
What is a uterine rupture?
full thickness opening of the uterus
What causes uterine rupture?
uterine surgery - myomectomy obstructed labour multiparity + use of prostaglandins/syntocinon 1 in 250 if induction of labour 1 in 500 with previous c/section
What are the symptoms of uterine rupture?
severe abdo pain
shoulder tip pain
maternal collapse
PV bleeding
What are the signs of uterine rupture?
loss of contractions
presenting part rises
peritonism
foetal distress/intrauterine death
How is uterine rupture managed?
same as placenta previa and accreta
What is vasa previa?
AN EMERGENCY - mortality 60%
unprotected foetal vessels transverse the membranes below the presenting part over the internal cervical os
these rupture during labour or at amniotomy causing a foetal haemorrhage
How is vasa previa diagnosed?
USS TA and TV with a doppler
How does vasa previa present?
artificial rupture of membranes and sudden dark red bleeding and foetal bradycardia
What is type 1 vasa previa?
connected to a velamentous umbillical cord
What is type 2 vasa previa?
when it connects to the placenta with a succentiate or accessory lobe
What are the risk factors of vasa previa?
placental abnormalities - bilobed
history of low lying placenta in 2nd trimester
multiple pregnancy
IVF
How is vasa previa managed?
steroids from 32 weeks
emergency c/section and neonatal resuscitation if rupturesd vasa previa during labour
deliver by c/section before labour ideally
placenta for histology
What is a post partum haemorrhage?
blood loss of >500mls after the birth of the baby
What constitutes a primary PPH?
within 24hours of delivery
What constitutes a secondary PPH?
> 24hours -> 6 weeks post delivery
What is a minor PPH?
500-1000ml
What is a major PPH?
> 1000ml or signs of cardiovascular collapse
What causes a PPH?
4 Ts!! Tone - 70% - uterine atony Trauma - 20% - c/sections and forceps Tissue - 10% - episiotomy Thrombin - < 1%
What are risk factors for a PPH?
anaemia previous c/section, placenta previa or accreta, PPH, retained placenta polyhydroamnios obesity fetal macrosomnia
What are intrapartum risk factors for PPH?
prolonged labour
operative vaginal delivery
c/section
retained placenta
What can be used as prophylaxis of PPH?
uterotonic agents: 5 units IV syntocinon + foleys catheter 500mg ergometrine IV carbopost/haemabate 250mg every 15 mins IM misoprostol 500mg PR tranexamic acid 0.5-1g IV
What can be done to stop the bleeding in PPH?
uterine massage
surgery - sutures, uterine artery ligation, internal iliac artery ligation, hysterectomy
packs and balloons, arterial embolisation
