High Risk Pregnancies Flashcards
When does Rhesus isoimmunisation occur?
If foetus is D Rhesus positive, and mother is D Rhesus negative
What is Rhesus isoimmunisation?
Occurs when a maternal antibody response is mounted against foetal red cells.
These igG antibodies cross the placenta and cause foetal RBC destruction
Mild: neonatal jaundice, anaemia, haemolytic disease of the newborn
Severe: cardiac failure, ascites, oedema, foetal death
What are sensitising events?
TOP and ERPC Ectopic pregnancy Vaginal bleeding Miscarriage OVER 12 weeks External cephalic version Amniocentesis or CVS Delivery
When should Anti D be given to prevent Rhesus haemolytic disease?
28 and 34 weeks
After sensitising events (250 units before 20 weeks, 500 after)
In all Rhesus negative women
Postnatal anti d if baby is Rhesus positive (500 units)
How can the foetal blood group be assessed?
Fathers blood group
PCR of foetal cells in maternal blood
When and how can foetal anaemia be assessed?
If the maternal antibodies are >10 IU/ml
Doppler of foetal middle cerebral artery
If Doppler velocity is increased, perform foetal blood sampling to assess haematocrit
When and how should foetal anaemia be treated?
If foetal haematocrit is <30
Packed red cells can be transfused into the umbilical vein - may need to be repeated
Anaemia can be corrected by transfusion after delivery
Does blood pressure rise or fall in normal pregnancy?
Blood pressure falls until 24 weeks due to decrease in vascular resistance
Blood pressure rises after 24 weeks due to increase in cardiac output
How many women with pre-existing hypertension go on to develop pre-eclampsia?
25%
What is pregnancy induced hypertension?
Hypertension greater than 140/90 in the second half of pregnancy
This occurs in the absence of proteinuria and other markers of ore-eclampsia
How common is pregnancy induced hypertension?
Affects 6-7% of pregnancies
Increased risk of going in to get pre-eclampsia (15-26%)
When should a woman with pre-eclampsia/hypertension be admitted?
BP >140/90 and proteinuria
Symptoms of pre-eclampsia
Foetal distress on ctg, umbilical artery Doppler wave form, biophysical profile
What are the maternal complications of pre-eclampsia?
Cerebrovascular haemorrhage Eclampsia Hepatic coagulopathy - hellp syndrome Pulmonary Renal
What are the foetal complications of pre-eclampsia?
Prematurity - often results from necessary intervention
IUGR due to placental insufficiency
Placental abruption
How is pre-eclampsia managed?
Consider oral treatments - BP>170 requires treatment
Labetalol
Nifedipine
Methyl dopa
Delivery may be an option
How is eclampsia managed?
Control airway/O2
IV diazepam until fits stop
IV magnesium sulphate
What is IUGR?
A foetus that is pathologically small
What are the maternal causes of IUGR?
Chronic maternal disease - HTN, CKD Alcohol and substance abuse Smoking Autoimmune disease Genetic disorders - phenylketonuria Poor nutrition Low socio-economic status
What are the placental causes of IUGR?
Abnormal trophoblast invasion - pre-eclampsia and placenta accreta Infarction Abruption Placenta previa Placental haemangioma Abnormal umbilical cord - two vessels
What are the foetal causes of IUGR?
Genetic abnormalities:
trisomy 13, 18, 21
Turners syndrome
Triploidy
Congenital abnormalities:
Tetralogy of fallot, transposition
Gastroschisis
Congenital infection: CMV Rubella Toxoplasmosis Multiple pregnancy
What is symmetric growth restriction?
A foetus whose entire body is proportionately small
Tends to be seen with early onset IUGR, often due to chromosomal abnormalities
What is asymmetric growth restriction?
Foetus which has a normal head size with small abdominal circumference and thin limbs
Seen in an undernourished foetus who is directing energy to maintain growth of vital organs such as brain and heart
Most often seen in placental insufficiency
What investigations are used to foetal growth and well being in IUGR foetuses?
Weekly umbilical artery dopplers
Daily CTG if Doppler waveforms are consistently abnormal
The compromised foetus is normally delivered once maturity is attained (37 weeks)
What is the long term outcome for IUGR babies?
Most congenitally normal IUGR babies go on to grow normally in childhood
However subtle differences may occur such as not reaching predicted height, or childhood attention and performance deficit
