Bleeding in pregnancy Flashcards
1
Q
antepartum haemorrhage
A
Any bleeding from the genital tract after 20 weeks and before the onset of labour
6% of women have bleeding during 3rd trimester
2
Q
causes
A
- Placenta previa
- Placental abruption
- No specific cause
- Other specific causes
- Vasa previa
- Uterine scar disruption
- Vaginal infections
- Post-coital (sex)
- Heavy show
- Vulval varicosities
3
Q
for diagnosis consider…
A
- Colour and consistency of blood loss
- Predisposing factors
- Contractions
- Abdominal/back pain
- DFM
- Lie, presentation and engagement
- Degree of shock
4
Q
placenta previa
A
- Placenta is partially or completely implanted in the lower uterine segment on either the anterior or posterior wall.
- It either completely or partially covers the cervical os or impinges on the edge of the cervical os.
- Low-lying placenta in the second trimester is not uncommon, therefore repeat U/S is indicated at 30-32 weeks for placental localisation.
- Endometrial scarring: previous LSCS, TOP, previous placenta previa (4-8%), closely spaced pregnancies
- Impeded endometrial vascularisation: hypertension, diabetes, drug use, smoking, AMA
- Increased placental mass: multiple pregnancy
- Abnormally shaped uterus: fibroids, bicornuate
5
Q
placenta previa clinical features
A
- Uterus is soft and non tender
- Majority of women present with bright painless bleeding
- 27-32 weeks first bleed common
- Malpresentation or abnormal lie
- Centrally situated placenta have earlier more serve and recurrent bleeds
6
Q
management of bleeding with placenta previa
A
- Obs
- CTG
- Lateral position and gentle palpation
- Weight pads
- IV
- Group and cross match, Kleihauer and steroids if <34 weeks
- USS
7
Q
placenta abruption
A
- Premature separation of a normally implanted placenta
- Maternal haemorrhage occurring in the decidua basalis and causing separation
- Haemhorrage may be concealed, revealed or not, and may present itself as bloody amniotic fluid
- 3-5% pregnancies
8
Q
Conditions associated with placental abruption
A
- Hypertensive disorders
- Previous abruption (10%)
- Trauma
- Smoking
- Amphetamine use
- PROM (5%)
- Twins
- Polyhydramnios
- Lactrogenic
9
Q
clinical features placental abruption
A
- Dark vaginal bleeding
- Abdominal or lower back pain
- Uterine hypertonus
- Uterine contractions:
- ↑frequency and ↓amplitude
- Uterine tenderness
- Fetal lie usually normal
- Fetal distress or fetal death
- Observations may be normal initially
- S/S of hypovolaemia are worse than expected compared to the observed external blood loss
10
Q
management of abruption
A
- Obs
- Palpation
- CTG
- Lateral position
- PV loss monitor
- IV steroids if <34 weeks
- Group and cross match Kleihauer, FBC
- US
11
Q
complications of abruption
A
- Maternal shock
- Anaemia
- Couvelaire uterus
- Infection
- PPH
- DIC: coagulation failure as a result of consumption of clotting factors and/or development of fibrinolysis
- Oliguria, renal failure (rare) due to hypovolaemic shock
- Anterior pituitary necrosis (Sheehan Syndrome)
- Treatment: rapid transfusion with whole blood, FFP and/or platelet transfusion, cryoprecipitate
- Prematurity, fetal distress and fetal death
12
Q
vasa previa
A
- Vasa previa rarely causes third trimester bleeding.
- Occurs when a velamentous insertion of the umbilical cord crosses the cervical os ahead of the presenting part.
- Diagnosis often unknown.
- Usually presents with significant bleeding associated with ROM.
- High perinatal mortality around 60%
13
Q
vasa previa management
A
- Since bleeding is from a fetal source there is danger of fetal exsanguination and death in over 60% of cases if an OT is not in close proximity. NB: blood volume of a term fetus is approximately 250ml.
- If diagnosed prior to labour, elective LSCS is performed and survival rate as high as 97%.
- After ROM fetal distress is profound and disproportionate to the amount of visible blood loss.
- Once vasa previa is confirmed in the presence of a live fetus, LSCS is performed.
14
Q
blood and blood products
A
- Indications: acute, massive haemorrhage, operative complications.
- Types:
- Whole blood: RBC, white cells, platelets and plasma
- Blood fractions: albumin, anti-D.
- Anti D and Rhesus isoimmunisation.
- Refusal issues, personal beliefs,
- Jehovah’s Witness patients.
15
Q
APH SUMMARY
A
- Assessment of general condition.
- General appearance. Signs of shock?
- Vital signs.
- Blood loss: Colour? Amount? Onset?
- History: any predisposing factors?
- Palpation: guarding/tense?
- Assess fetal condition. How?
- NO VE. Speculum and ultrasound to confirm diagnosis.
- Pain relief.
- Reassurance and explanation.
- IV access, group and cross match, Anti D?
- Subsequent management depends on degree of blood loss and maternal and fetal condition.
16
Q
rhesus isoimmunisation
A
sensitisation of a species with antigens from the same species. This can occur in mismatched blood transfusion or where a woman is Rhesus negative and the fetus is Rhesus positive.
Fetal blood cells can pass into the maternal circulation which may cause her to produce antibodies against the foreign cells. The antibodies she produces can cross the placenta, entering the fetal circulation and cause haemolysis.
17
Q
pathophysiology of rhesus isoimmunisation
A
The widely dilated uteroplacental vessels encouraging blood flow, facilitate antibody formation
Maximum maternal blood volume increases between 28 and 32 weeks gestation and further facilitates dilation of these vessels.
The formation of antibodies is gradual in the mother and not likely to affect the first pregnancy.
Changes in fetal blood pressure are responsive to changes in blood flow in the maternal circulation, and may also account for increased chance of fetal erythrocytes breaking into the intervillous space.
Aside from delivery, the second most likely time for Rh D isoimmunisation to occur in the mother is at 28 weeks gestation
18
Q
placental transport
A
- Placenta provides a large area in which exchange of nutrients and waste can take place across the placental membrane
- Membrane consists of fetal tissues that separate maternal and fetal blood
- As pregnancy advances the placental membrane becomes thinner, and some fetal blood cells may pass into the maternal blood in the intervillous space
19
Q
when does isoimmunisation occur
A
- There is a risk of isoimmunisation in any situation in which Rh positive red blood cells enter the circulation of an Rh negative woman.
- The degree of this risk will vary with the amount of rhesus antigen to which she is exposed.
- A small proportion of women (1.5%) develop rhesus antibodies during their first pregnancy however most isoimmunisations take place after 28 weeks gestation.
20
Q
fetal effects
A
- In the fetus, signs of anaemia and impending hydrops fetalis (ascites, oedema, polyhydramnios and enlarged placenta) include the following:
- A baseline rate of 180bpm or greater
- Late decelerations or loss of short term variability with presence of regular sine wave long-term variability; the sinusoidal pattern
- Decreased fetal activity
- Fetal ascites or congestive heart failure seen on U/S
21
Q
antibody screening (diagnostic)
A
- At ‘booking-in’: indirect Coombs test.
- Repeated at 28 weeks as thinner placental membrane and greater risk of transplacental transfusion.
- Severity of a fetal bleed:
- Kleihauer blood test on the mother to detect the presence of fetal cells that have entered the maternal circulation.
22
Q
middle cerebral artery (MCA) doppler velocity
A
- Colour-flow Doppler now used to visualise the middle cerebral artery.
- Pulsed Doppler measures the peak systolic velocity of the MCA.
- It measures fetal Hb to detect fetal anaemia.
- In the presence of anaemia the increased fetal output and a drop in blood viscosity causes an increased blood flow velocity in the cerebral artery
23
Q
medical management - fetal surveillance
A
- Transfer to tertiary hospital/NNIC unit.
- EFM monitoring from 26 weeks, EFM frequency and/or hospitalisation dependent on fetal condition.
- U/S and MCA (doppler) studies.
- FM by the mother
24
Q
medical management - intrauterine transfusions
A
- Done by skilled doc
- If fetus anaemic after 18 weeks
- Allows extra time for fetal maturity and for the non-viable fetus to remain in utero
- May be done intravascularly or intraperitoneally under US guidance
- PUBS: using the percutaneous umbilical vein in the umbilical cord to take an umbilical blood sample
25
prevention of rhesus isoimmunisation
- To prevent sensitisation occurring in unsensitised RhD negative women, prophylactic anti-D immunoglobulin is used
26
anti-d
- The immunoglobulin which is offered to Rh negative mothers after TOP, miscarriage, ectopic or birth unless the infant is also Rh negative. It can prevent the mother from developing antibodies to the Rh positive factor which may pass into her circulation during placental separation. The immunoglobulin coats the fetal blood cells so that the mother’s body does not recognise them as foreign proteins.
- Cannot correct sensitisation but can prevent it occurring if given within 72 hours of the potential fetomaternal red blood cell transfusion.
27
midwifery management
- Prevention: Accurate booking-in history for EDC, antibody screening at ‘booking-in’ and at 28 weeks.
- Patient education (to Rh negative women)
- IMI administration of Anti-D following sentinel events and routine prophylaxis.
- Be aware that so-called ‘silent feto-maternal transfusions’ may not be detected and/or treated during pregnancy
- Fetal growth monitored and referred if slowed growth, decreased FM or polyhydramnios.
- Educate the mother about fetal movements.
- EFM for tachycardia, loss of variability, sinusoidal pattern, late decelerations.
- Education and preparation for premature delivery, probable LSCS and exchange transfusions for baby in NICU.
- accident and emergency admissions require testing and administration of Anti D for Rh negative women with abdominal trauma, miscarriage.
- cases lost to G.P follow up.
- follow-up in rural areas.
28
postnatal issues
- The most common time for Rh-positive fetal cells to enter the mother’s circulation is at the birth of a Rhpositive baby.
- Woman and baby assessed for Anti-D through the direct Coombs’ test and the Kleihauer test
- Test baby’s blood group and Rh factor from cord blood, if Rhesus negative, no Anti D required.
- If baby Rhesus positive Anti D must be given to the woman within 72 hours of a vaginal or caesarean delivery.
- For the unsensitised RhD negative woman education & prevention are the primary goals:
1. Antibody screening at the first visit.
2. Antibody screening at 28 weeks.
3. Giving Anti-D at 28 and 34 weeks.
4. Giving Anti-D within 72 hrs post delivery or following any potential placental incident, TOP, miscarriage, stillbirth.
