Antenatal Care Flashcards
How many women get morning sickness?
80-85%
When is morning sickness worse and what do we call the extreme form?
Worse when Human Chorionic Gonadotrophin is high e.g. in twins or molar pregnancies
Can progress to Hyperemesis Gravidarum
Why does pregnancy increase Cardiac Output?
Normal pregnancy raises CO from 30-50% due to HR rising from 70-90BPM
This is to maintain a high blood flow to the foetus
This can present as palpitations
How does blood pressure change physiologically during pregnancy & why?
Drops during the 2nd trimester
A mixture of effects:
- Uteroplacental circulation expands
- SVR drops
- Blood viscosity drops
- Angiotensin sensitivity drops
When does BP return to normal during pregnancy?
Third trimester
Why does urine output increase in pregnancy?
Renal plasma flow and GFR increase
Serum Urea & Creatinine also decrease
Why are pregnant women more at risk of UTIs?
Urinary stasis increases, in fact, hydronephrosis is even physiological come the 3rd trimester.
Making UTIs and pyelonephritis very common
What is the major danger of a UTI to a pregnant woman?
Preterm labour.
So very important to treat them
Why are pregnant women at risk of anaemia?
Because plasma volume increases by 50% but RBC mass only goes up by 25%
So a lower Haemoglobin is normal in pregnancy but you still want to ensure it doesn’t drop too low.
How does pregnancy affect blood cell counts?
WBC count increases slightly
Platelet count falls (due to rise in blood volume not loss of platelets)
How does pregnancy affect the lungs?
Progesterone acts to reduce CO2 by:
- Increasing tidal volume
- Increased Resp rate
- Increases plasma pH
This increases O2 consumption by 20% but plasma PO2 is unchanged
You also get hyperaemia of the resp mucous membranes
How does pregnancy affect the GI system?
GI motility is reduced, specifically:
Oesophageal peristalsis reduced
Gastric emptyin slows
Cardiac sphincter relaxes
What hormones cause GI motility to be decreased in pregnancy?
- Increased Progesterone
- Decreased Motilin
What are some normal symptoms of physiological changes in pregnancy? (i.e. symptoms mothers get in normal pregnancies?)
Nose bleeds from resp mucous membrane hyperaemia
SOB from progesterone increases resp rate etc
Constipation & GORD from reduction in GI motility & pressure of foetus
Palpitations from increased HR
Whats included in pre-preganancy counselling?
Diet
Optimise BMI
Alcohol reduction
Smoking cessation
Folic Acid supplements Rubella immunisation (if needed)
Optimise maternal health, mental health and medications
Advise on maternal complications
When would you advise against pregnancy in pre-pregnancy counselling?
In certain conditions like Diabetes or Epilepsy
Many maternal issues may recur in the next pregnancy, give 3 examples of these that are important in pre-pregnancy counselling?
Caesarean section
DVT
Pre-eclampsia
Pre-term delivery
Intrauterine growth restriction
Fetal Abnormality
Whan can we do at pre-regnancy counselling to reduce the risk of previous problems recurring?
Thromboprophylaxis if h/o DVT aka low dose aspirin
Treat any infections
High dose folic acid to reduce abnormalities
Whats involved in a routine antenatal exam?
- Feeling well?
- Feeling fetal movements (>20wks)
- BP
- Urinalysis
- Abdominal palapation
- Listen to fetal heart
Abdominal palpation is an important part of an antenatal exam, what can it tell us?
- Fetal presentation
- Sympheseal Fundal height (SFH)
- Estimate baby size
- Estimate Liqour volume
How do we determine which mothers to do antenatal screening on?
We dont.
We offer it to everyone but its not compulsory
What is looked for on an Antenatal screen?
- Hepatitis B
- Syphilis
- HIV
- MSSU for UTI
- Rubella
- Fe-deficient Anaemia
- Isoimmunisation e.g. Rhesus disease
US scans for physical abnormalities
Down syndrome
Neural Tube defects
How do we treat if a basic antenatal screen throws up an infection in the mother?
Hep B give passive & active immunisation to baby
Syphilis give penicillin
HIV give maternal treatment to prevent vertical transmission
How many US scans are women offered?
One in their first and 1 in their second trimesters
What is shown on a 1st visit US?
Is the pregnancy viable?
Single or multiple pregnancy?
Abnormalities incompatible with life
When is down syndrome testing offered?
10-14 weeks gestation
How do we initially test for Down’s Syndrome?
- Serum B-human Chorionic Gonadotrophin (Beta-hCG)
- Pregnancy associated plasma protein A (PAPP-A)
- Fetal Nuchal Translucency (NT)
How does fetal nuchal translucency help identify Down’s Syndrome?
Based on the size of the nuchal translucency, it increases with age so:
Risk of Down’s is related to size of NT relative to the maternal age.
From initial tests how do we decide if a fetus requires further testing for Down’s?
Initial screening give a 1 in something risk of Down’s.
Further invasive tests are offered if risk is estimated at > 1in150
What further tests are available for Down’s?
Chorionic Villus sampling (CVS) (10-14wks)
Amniocentesis (>15wks)
Non-invasive Prenatal Testing
These all have a small but significant risk of miscarriage (<1 -> 2%)
How does Non-invasive prenatal testing for Down’s Work?
Its done after initial testing if high risk
Take maternal blood and detect fetal cell free DNA then look for Trisomies.
However its not on NHS (yet, it will be soon)
How do we screen for neural tube defects?
Part of the first trimester US, should pick up anencephaly & sometimes Spina bifida
Possibly 2nd trimester biochemical screening
2nd trimester US
Why & how would we do 2nd trimester biochemical screening?
If we couldn’t get a NT measurement from the US
Take maternal serum alpha fetoprotein. >2MoM is high risk
What does and doesnt show on a 2nd trimester US?
Picks up >90% of major structural abnormalities e.g. exomphalos and cleft palate
But misses a number of chromosomal abnormalities such as Downs, T13 or T18
In summary:
Pregnancy causes physiological changes that may present as “symptoms”
Pre-pregnancy counselling is essential for any woman with increased complication risk
Various investigations & examination are available to test for abnormalities
Initial screening includes a history, US & Maternal serum biochemistry
