Antenatal screening Flashcards
What can be the consequences of congenital rubella?
can lead to deafness, brain damage, heart defects and cataracts
When is amniocentesis carried out?
done between 15 and 20 weeks
What is chorionic villous sampling (CVS)?
where a sample is taken of the placenta
When does CVS take place?
10-13 weeks
What is amniocentesis?
where fluid is aspirated that contains fetal cells shed from the skin and gut
What is the main risk of amniocentesis and CVS?
miscarriage
What is karyotyping?
place chromosomes in order from largest to smallest to see is any extra/missing/damaged
What is nuchal translucency?
fluid at the back of the neck of fetus - indicates fetal heart abnormality and downs
What is a trisomy?
extra copy of a particular chromosome in each cell
What are trisomies 21, 13 and 18
Trisomy 21 (downs)- means there’s an extra copy of chromosome 21 in each cell. Can cause heart defects, intellectual disability and increased chance of epilepsy, leukaemia and dementia
Trisomy 18 (Edwards) - most die at birth or soon after, have severe abnormalities, have small chin and low set ears
Trisomy 13 (Patau’s) - most die soon after birth, will have congenital heart defects, microcephalopathy, cleft palate, facial defects, UG malformations, abnormal hands and feet etc.
What is the combined test vs quadruple test?
Combined test 🡪 Nuchal translucency and PaPP-A
and B-hCG (11-14 weeks)
Quradruple test 🡪 B-hCG, AFP, Inhibin-A and free estriol 3 (after 14 weeks)
What are the results of the screenings in the trimosies?
diwns:
Low alpha fetoprotein (AFP)
Low oestriol
High human chorionic gonadotrophin beta-subunit (-HCG)
Low pregnancy-associated plasma protein A (PAPP-A)
Low inhibin A
Thickened nuchal translucency
trisomy 18 (Edward syndrome) and 13 (Patau syndrome) give similar results but the PAPP-A tends to be lower
What is PAPP-A
pregnancy-associated plasma protein A - rpoduced by placenta and indicates good placenta implantation
What is the wilson junger criteria for screening?
There needs to be good knowledge of the test, disease, treatment and be cost-effective to be an acceptable screening procedure
What should be asked about at the booking clinic?
Personal: fertility, PMH (thyroid, DM, asthma, epilepsy, asthma, htn, heart or renal disease), BMI, mental health, smoking and drugs, DA
Fhx: congenital abnormality, pre-eclampsia, VTE, DM, inherited conditions, MHP first degree relative
Obstetric hx: miscarriage or stillbirth or neonate death, past pre-eclampsia, gestational DM, rhesus, induction, operative birth, breech, shoulder dystocia, PPH
Currently: hyperemesis, PV bleed, abdo pain, USS
Screening: FBC for anaemia and thrombocytopenia, blod group, rubella, Hb electophoreisis, hep B, syphilis, HIV
When are the USS?
First one at 10-14 weeks used for viability and dating pregnancy
Second one at 18 weeks-20 weeks+6 days. For structural abnormalities –gives chance to terminate
What infectious diseases do we screen for?
HIV
Hep B
Syphilis
What haemoglobinopathies are screened for if lady or partner is at higher risk?
Alpha and beta thalassemia’s
SCD
What new born screening tests do we do?
Heal prick test/ blood spot at 5-8 days
Look for CF, haemoglobinopathies, congenital hypothyroid
Inherited metabolic disorders eg phenylketonuria
Hearing screening
NIPE – new born and infant physical exam for congenital heart defects, eye problems, dysplasia of the hips, undescended testes.
What infections do we not routinely screen for and only do if lady is at risk of them?
chalmdyia CMV toxoplasmosis herpes rubella
What are the routine booking investigations offered?
urine culture FBC syphilis serology HIV and hep B glucose tolerance test rhesus status
How are haemoglobinopathies screened for?
electrophoresis
What medications should be prescribed for women during pregnancy?
Vit D and folic acid supplements
aspirin if risk of pre-eclampsia
What immunisation should pregnant women get?
flu vaccine and pertussis
hep B if high risk
