Antenatal screening

Question 1

What happens during the booking appointment?

Answer 1

Detailed history - e.g. abortions, miscarriages, previous births
DH/FH/Medical history/SH
BMI, BP, Epilepsy, Diabetes
Blood test - FBC, Rh status, Bld grp
Haemoglobinpathies, anaemia, red cell allo antibodies, Hep B, HIV, Rubella, Syphilis
Urine culture, proteinuria (kidney disease)
VTE risk
Domestic violence

Question 2

Between what weeks does the booking appointment occur?

Answer 2

8-12 weeks

Question 3

What are the primary functions of the first trimester scan?

Answer 3

Dating - gestational age
Detect multiple pregnancy
Screen for T21, T18, T13

Question 4

What is T21?

Answer 4

Downs syndrome

Question 5

What is T18?

Answer 5

Edwards syndrome

Question 6

What is T13?

Answer 6

Patau syndrome

Question 7

What are invasive tests if trisomy 21/18/13 is suspected?

Answer 7

CVS - small villi - trophoblastic cells taken (10-13wks)
Amniocentesis - after 15wks, fetal fibroblasts/fluid taken
Cordocentesis - umbilical vein blood sampling, 18-20wks, fetal white blood cells taken

All samples taken can then be analysed: cytogenic, DNA analysis, biochemical

Question 8

What are non-invasive tests if trisomy 21/18/13 is suspected?

Answer 8

Fetal DNA - cell free fetal DNA, blood group status, single gene mutations, aneuploidy
Intact fetal cells, trophoblasts, lymphocytes - FISH to idenytify any probles in DNA/cells

Question 9

How is PET/IUGR screened?

Answer 9

High resistance to uterine artery doppler

Question 10

How is preterm labour screened?

Answer 10

Cervical length via US