Antenatal care Flashcards
How is pregnancy diagnosed
CF: secondary amenorrhoea, N+V (commonly within 2w of missing period, morning or any time), frequent micturition, excessive lassitude (for T1), breast tenderness (progesterone + water retention), maternal perception of fetal movements (~20w in first preg or 18w in other pregs), pica (wanting particular food)
Beta-hCG in urine/serum after ~10d post-conception
- False positives
- positive hCG without pregnancy - trophoblastic neoplasms
How is pregnancy dated?
- First day of the LMP - some idea of age but often inaccurate
- US in T1 to confirm gestational age
- EDD: 9m + 7d added to the first day of the LMP, or subtract 3m from the first day of the LMP and add 7d (Naegele’s rule) – not that accurate as women often dont know LMP, relies on a regular 28d cycle, assumes conception happened at point of ovulation
- 40% deliver within 5d of the EDD, and 2/3 within 10d so is a rough guide
- If normal cycle is >28d subtract/add appropriate number to the EDD
What is pseudocyesis?
Sx of pregnancy in a woman who isn’t pregnant - often due to fear/desire of pregnancy resulting in hypothalamic amenorrhoea
How many appointments should a woman with uncomplicated pregnancy have? What should be done at each?
- Nulliparous - 10
- Parous - 7
Check BP + urine for protein, and from 24w measure the symphysis-fundal height on growth charts
What is the booking appointment?
- Done before 12w
- Full history
- Maternal bloods: FBC, blood grouping + Rh, red cell alloantibodies, haemoglobinopathies (if at risk/at risk area), hep B, syphilis, rubella, HIV
- Explanation of screening tests
- Adv about diet, ensuring enough vitamin D, avoiding alcohol + certain foods
- General info about stages of pregnancy, antenatal classes
When is the combined test offered?
11-14w
When is the quadruple test offered?
15-20w, if they missed the combined one
What scans are routinely done for an uncomplicated pregnancy?
- Early pregnancy scan between 10-13w : confirm viability, singleton/multiple, estimate gestational age, detect major abnormalities like anencephaly (often combine with combined test as can check nuchal translucency)
- Fetal anomaly scan 18-20w
What vaccinations are recommended for pregnant women?
- Influenza
* Pertussis
What is tested at 28w?
FBC for anaemia
Red cell antibodies again
OGTT if they have RF
What is the rationale behind the NHS Fetal Anomaly Screening Programme?
Identify fetal problems in asymptomatic women, that may result in incompatibility with life/severe disability or benefit from early paed/antenatal treatment
Allows parents to be offered further tests, prepare for otherwise unexpected neonatal needs, have a TOP, manage birth in a specialist centre
They don’t have to have it
What does high risk screening result mean?
A greater than 1/150 chance of having the condition
What conditions does the FASP screen for?
- Chromosomal abnormalities - these are higher risk with maternal age. Down’s syndrome T21, Edward’s syndrome T18 and Patau’s syndrome T13
- Structural abnormalities - may benefit from antenatal treatment, or help with plans for delivery/postnatal, or indicate baby might die
What are the limitations to screening?
- False positives + false negatives
- Varying sensitivity + specificity
- Scan quality can be compromised by a high BMI, abdominal scars or a sub-optimal fetal position
What biochemical markers are used in screening?
- Beta-hCG: made by SCTB then placenta; high in T21, low in T18+13
- PAPP-A: made by placenta, if low in T1 is a/w T21+18+13
- Alpha fetoprotein: made by yolk sac+liver, high in NTD, low in T21 (in T2)
- Unconjugated estriol: made by placenta, low in T21 (in T2)
- Inhibin A: made by CL+placenta, high in T21 (in T2)
