Antenatal care and screening Flashcards
Describe the pattern of antenatal care for a low risk pregnancy?
Last menstrual period
12 weeks: booking appointment
- FBC (iron deficient anaemia common in preg.)
- ABO and Rh(D) screen
- Glucose
- Syphillis/Rubella/HIV/Hep B +C
- Antibodies
- Ht/Wt/BP/CVS/Abdo
- Urinalysis: MSSU for C+S
- USS: confirm viability, no of preg., confirm gestation
13 weeks: DOWNS
- USS nuchal thickness
- Maternal serum bHCG (would be up), PAPP-A (would be down)
- this can be done 11-13+6wks
16 weeks: DOWNS - AFP or triple test
- low AFP, low oestriol, high BHCG (+high inhibin if quadruple test)
- can be done 15-20wks
- then incorporation of results with maternal age + gestation to work out personal risk, if this >1:250 = high risk = further Ix
18 weeks: FETAL ABNORMALITY
- 12-20 look for cardiac anomaly
- detailed brain malformation
22weeks: microcephaly and short limbs
- this can be done after 22 weeks
20-24weeks:
-MUAD for PET
28weeks: anti D is Rh(D)-ve
34 weeks:
- FBC
- Anti-D
40 weeks - due date (term 37-42+0)
What constitutes 1st/2nd/3rd trimester
1st: 0-12wks
2nd: 13-27wks
3rd: 28-40
What are the commonest 5 groups of foetal defects?
- Neural tube
- Congenital cardiac
- Down’s syndrome
- Cleft lip/palate
- defects of bowel wall
What decreases the risk of neural tube defects?
-pre and post conceptual folic acid supplementation
What defects of the bowel wall exist?
- gastrochisis
- exomphalos
What is gastrochisis?
Bowel extruded outside abdominal cavity separate from umbilical cord, doesnt have a peritoneal covering and is usually an isolated problem
What is exomphalos?
bowel extruded outside abdo cavity and is a large herniation of umbilical cord, has peritoneal covering and increases the risk of underlying chromosomal abnormality
What additional investigations can be done for down’s screening?
After 15 weeks: amniocentesis
-miscarriage rate 1%
After 12 weeks: chorionic villus sampling involving placental biopsy
-miscarriage rate 2%
