Antenatal screening and care Flashcards
What is meant by the term gravidity?
Number of pregnancies a woman has had regardless of outcome
What is mean by the term parity?
Pregnancies that resulted in delivery beyond 28 weeks gestation
What is meant by para 2+1?
2 Pregnancies beyond 28 weeks, 1 terminated prior to 28 weeks
If a woman had had 3 full term children and was pregnant with another, what gravidity would she be?
Gravida 4
How long does pregnancy normally last?
40 weeks from LMP
How would you roughly calculate the expected delivery date?
EDD = Approximately 1 year and 7 days after LMP - 3 months
What is crown/rump length used to calculate?
Gestation between 8 and 13 weeks
How is crown/rump length measured?
On USS, measurement from one foetal pole to the other along its longitudinal axis
When should booking visit take place?
12 weeks gestation
What weeks of pregnancy are the first trimester?
1st day since LMP to 12 weeks
What weeks of pregnancy are the 2nd trimester?
13-28
What weeks of a pregnancy are the 3rd trimester?
Weeks 29 - 40
What aspects of the history would you wish to obtain at first booking?
- Gravidity/Parity
- Usual cycle length
- LMP
- Drugs/contraception
- PMH
- Any fertility probems/oucomes of past pregnancies
- History of diabetes/HTN/foetal abnormality/Twins
- Concurrent illness
- Past mental illness
- Education/Social status - poor, unsupported, substance abuser etc.
How would you describe the gravidity and parity of a woman who is pregnant for the 4th time with 1 previously normal delivery at term, 1 termination at 9 weeks and 1 miscarriage at 16 weeks?
Gravida 4, Para 1+2
What are the basic aims of antenatal care?
- Provide evidence based information
- Advise on minor problems and symptoms
- Assess foetal and maternal risk factors at onset of pregnancy
- Facilitate prenatal screening and subsequent management of abnormalities
- Monitor foetal and maternal wellbeing
- Determine timing and mode of delivery
What bedside tests should be performed at every antenatal visit?
BP and urine dipstick
What should be covered at first antenatal appointment?
- Calculate BMI
- Measure BP
- Dipstick
- US for gestational age and gross abnormalities
- Blood tests
- Give information - folic acid, lifestyle, screening, AN classes, diet and supplementation
What screening tests are done when looking for anaemia and isoimmunisation?
- FBC
- Anti-D
- Anti-C
- Anti-Kell
What is involved in an antenatal examination?
- Routine enquiry - feeling well, foetal movements
- BP
- Urinalysis
- Abdominal examination
What tests are done when screening for infection in a pregnant woman?
- Hep B
- HIV
- Syphillis
- MSSU
- (Rubella)
What is looked for on first visit scan?
- Ensure pregnancy viable
- Multiple pregnancy
- Identify abnormalities incompatible with life
- Can offer down’s screening
How would you describe the following lie?
Longitudinal lie
How would you describe the following lie?
Longitudinal lie
What presentation is the following?
Breech
What lie is the following?
Transverse lie
What presentation is the following?
Vertex presentation
What are the main aspects of pre-pregnancy councelling?
- General health management - diet, BMI, alcohol, Smoking
- Folic acid
- Risk assessment - Age, Parity, occupation, Substance misuse, psych history
- Medication review
What previous pregnancy problems increase maternal risk?
- C-section
- DVT
- Pre-eclampsia
What previous pregnancy problems increase foetal risk?
- Pre-term delivery
- Intrauterine growth restriction
- Foetal abnormality
What are important maternal factors for increasing risk of down’s syndrome in a baby?
- Increasing age
- Family history
What is the risk of a neonate exposed to maternal Hep B becoming a carrier?
90% - can progress to liver cirrhosis and HCC
What is recommended for treatment of a neonate whos mother is Hep B core antigen +ve?
Active and passive immunisation
When is screening for down’s syndrome commonly carried out?
10-14 weeks gestation
How is down’s syndrome screened for?
- Assess Maternal risk factors - age, FH
- B-HCG
- PAPP-A
- Foetal nuchal translucency
Where is the nuchal transluceny measurement tacken from?
Between crown/rump length of 45-84 mm
How is nuchal translucency related to chromosomal/other abnormalities?
Related to size - increased size increases risk of there being an abnormality
How can risk of vertical transmission of HIV be reduced?
-
Anteretroviral treatment
- Pregnancy
- Labour
- Neonataly - 6 weeks
- C-section
- Avoidance of breastfeeding
How is B-HCG and PAPP-A related to trisomy 21?
Increased B-HCG and PAPP-A - Increased risk
What options are available if screening tests for downs syndrome come back as high risk?
- Chorionic Villous Sampling
- Amniocentesis
- Non-invasive Prenatal testing
What is involved in chorionic villous sampling?
It entails sampling of the chorionic villus (placental tissue) and testing it for chromosomal abnormalities, usually with FISH or PCR.
When is CVS performed?
Weeks 10-14
What is the risk of miscarriage from chorionic villous sampling?
1-2%
What is inovled in amniocentesis?
Sampling a small amount of amniotic fluid through a transabdominal needle aspiration
When is amniocentesis most commonly performed?
>15 weeks gestation
What is the risk of miscarriage in someone having an amniocentesis?
Approximately 1%
If someone had a family/personal history of neural tube defect, how should they be managed?
5mg folic acid
What abnormalities are incompatible with life on first US?
Anencephaly
What is the main purpose of 20 week scan?
Used to detect foetal abnormality - more sensitive for structural rather than chromosomal abnormalities
What proportion of NTDs will be detected on first scan?
<10%
What proportion of NTDs will be seen on 20 week scan?
>90%
How would you measure the fundal height?
Estimated in centimetres from the upper border of the fundus to the pubic symphasis
How does the height of the fundus correlate with gestational age?
Height in cm correlates with gestational age in weeks
