Antenatal Care and Screening Flashcards
What is screening?
A process of identifying apparently healthy people who may be at increased risk of a disease or condition. They can then be offered information, further tests and appropriate treatment to reduce their risk and/or any complications arising from the disease or condition
What promotion/advice can be given to expecting mothers in primary care to provide pre-pregnancy counselling?
- General health measures:
- Improved diet
- Optimize BMI
- Reduce alcohol consumption
- Smoking cessation
- Folic acid (400mcg standard, 5mg high dose)
- Vitamin D (10mcg daily)
What is the:
a) Standard dose of folic acid prescribe pre-pregnancy?
b) High dose of folic acid prescribe pre-pregnancy?
a) 400 mcg
b) 5 mg
What is the dose of Vitamin D prescribed to women pre-pregnancy?
10 mcg daily
When should folic acid be started?
3 months before pregnancy
Which mothers should be on the higher dose of folic acid?
- BMI <30
- Medications: epilepsy using valproate
- Previous baby with spina bifida
What is important to cover in pre-pregnancy counselling?
- Optimizing maternal health
- Psychiatric health
- Stop/change unsuitable drugs
- Advise on complications associated with maternal medical problems
- Occasionally advise against pregnancy
What conditions is it important to be aware of if a woman had had them in a previous pregnancy to reduce the risk of recurrence in the present pregnancy?
Actions can be taken to reduce the risk of recurrence
Maternal
- C section
- DVT → thromboprophylaxis
- Pre-eclampsia→ low dose aspirin (150 mg until birth)
Fetal
- Pre-term delivery → treatment of infections
- Intrauterine growth restriction
- Fetal abnormality → high dose folic acid, low dose aspirin
What inquiry is involved in the antenatal examination?
- Routine
- Feeling well? Feeling fetal movements (after 20 weeks)
- Blood pressure
- Hypertension (pre-eclampsia)
- Urinalysis
- Abdominal palpation:
- Assess symphyseal fundal height (SFH)
- Estimate size of baby
- Estimate liquor volme
What are the screens that are done antenatally for infection?
Offered routinely
- Hepatitis B: if infective, passive and active immunization for baby
- Syphilis: treated with penicillin
- HIV: Matrenal treatment, planning reduced vertical transmission
- MSSU: UTI
What screening is done at weeks 12 and 28 of gestation?
- Iron deficiency anemia
- Isoimmunisation:
- Rhesus disease
- Anti-c antibody, Anti-Kell antibody
What is the purpose of the first trimester visit ultrasound scan?
- Ensure viable pregnancy
- Multiple pregnancies (type of pregnancy: monochorionic, dichorionic)
- ID abnormalities incompatible with life
- Offer/carry out Down’s / Pataus/ Edwards syndrome screening
What is the purpose of the detailed anomaly scan?
- Attempt to get systematic structural review of baby
- Not possible to ID all problems, but can ID intrauterine/postnatal treatment
Which condition that can be found on the detailed anomaly scan at the 1st trimester, are not viable with life?
- Anencephaly (spina bifida spectrum): skull bone doesn’t form, may survive a few hrs after birth, no long term survival
What information can be provided by the screening tests for Trisomy 13, 18 and 21?
The tests for foetal abnormality only provide a risk of their baby being affected
Prenatal screening may cause parents to make difficult decisions regarding termination of pregnancy
When is the 1st trimester screening carried out?
Weeks 10-14 gestation
What is measured during the 1st trimester combined test?
Uses:
- Maternal risk factors (age)
- Serum beta-human chorionic gonadotrophin (B-hCG)
- Pregnancy associated plasma protein A(PAPP-A) and
- Fetal nuchal translusency (NT) measurement
- Gestational age claculated from crown rump length (CRL)
All these factors are used to calculate e the chance of the pregnancy being affected by T21 or T18/T13
When is the optimal time to perform the 1st trimester combined test?
11+2 weeks to 14+1 weeks of gestation, which corresponds to a CRL (Crown rump length) of 45.0 mm to 84.0 mm.
If nuchal translucency cannot be measure during the 1st trimester combined test, when should it be offered?
At least 1 other attempt (same day/later date)
- Otherwise woman can be referred to 2nd trimester screening pathway
What is the Nuchal translucency (NT)? How is this measurement used?
Between 11+2 weeks and 14+1 weeks of pregnancy the thickness of fluid in the tissue space within the nape of the fetal neck, the nuchal translucency can be measured. An increased amount of fluid may indicate that the fetus has Down’s syndrome, structural or genetic anomaly. By combining the mother’s age and the gestation of the pregnancy with information from the scan an individual statistical chance of an anomaly can be given for that particular pregnancy. If the chance is between 1 in 2 and 1 in 150 a diagnostic test, such as CVS, will be offered
By what stage in the pregnancy must the screening pathway be completed?
23 weeks of gestation
What conditions are screened for during the 2nd trimester fetal anomaly scan?
What is the 2nd trimester quadruple screen?
The quadruple test uses:
- maternal age and
- four biochemical markers measured from 14+2 weeks until 20+0 weeks - AFP, hCG (total, intact or free beta subunit), uE3 and Inhibin-A
What are the next steps if the CRL measurement is:
a) Below 45.0 mm?
b) Above 84.0mm?
a) Recall woman for further scan to measure Nuchal traslusency
b) 2nd trimester scan quadruple test offered
