Antenatal care and screening Flashcards
When should the test for Down’s syndrome be done?
What does it involve?
Weeks 8-14 Confirms the pregnancy and the number of fetus' Dates the pregnancy Assesses the viability of the pregnancy Measures the nuchal rigidity
When is the dating scan carried out?
8-14 weeks
What does the term red blood cell isoimmunisation mean?
It is when maternal antibodies are formed in response to surface antigens on fetal erythrocytes
In which people is RBC isoimmunisation a problem?
Women who are rhesus negative and their baby is rhesus positive
(Or ABO incompatibility)
When are pregnant women tested for their rhesus status?
At their booking scan (weeks 8-12)
What treatment are women who are rhesus negative given? When is this given?
They are given rhesus D antibodies at any sensitising event and at birth if their baby is rhesus positive
AND
Given routinely:
Either 2 doses - 1 at week 28 and 1 at week 34 OR
1 dose between weeks 28-30
What are antibodies against a rhesus antigen otherwise known as?
Rhesus D antibodies
What is a ‘sensitising event’? What are examples of sensitising events?
An event where the babies blood is able to pass across the placenta into the maternal blood.
Miscarriage >12weeks ‘late miscarriage’ or TOP
Abdominal trauma
At birth
Bleeding during pregnancy
Invasive obstetric testing (e.g amniocentesis or chorionic villus sampling) or external cephalic version
Why is rhesus incompatibility more of a problem in a second pregnancy?
Because in the second pregnancy the antibodies have developed and are able to cross the placenta into the fetal blood and attack the fetal red blood cells there.
What are the 2 main blood tests that should be considered following a sensitising event?
Feto-maternal haemorrhage test
AND
Maternal blood group and antibody screen (ABO and RhD blood groups) and any antibodies present
What are some complications of untreated rhesus incompatibility?
Haemolytic disease of the newborn - raised bilirubin levels - jaundice and can get so high that results in kernicterus
What is a feto-maternal haemorrhage test?
A test that assesses how much fetal blood has entered the maternal circulation. If the event is >20W it is used to determine how much anti-D should be given.
What is Naegele’s rule? How is it calculated?
It is how the date of delivery is ESTIMATED
- Begin on the first day of the last menstrual period
- Subtract 3 months
- Add 7 days
- Add 1 year
EDD is when the woman is how many weeks?
40+0
When is a woman’s haemoglobin and antibodies tested for?
At booking bloods (week 8-12) and again at week 28
