Antenatal Care (bj)

Question 1

How many women get morning sickness?

Answer 1

80-85%

Question 2

When is morning sickness worse and what do we call the extreme form?

Answer 2

Worse when Human Chorionic Gonadotrophin is high e.g. in twins or molar pregnancies

Can progress to Hyperemesis Gravidarum

Question 3

Why does pregnancy increase Cardiac Output?

Answer 3

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

Question 4

How & when does blood pressure change physiologically during pregnancy & why?

Answer 4

Drops during the 2nd trimester

A mixture of effects:

• Uteroplacental circulation expands
• SVR drops
• Blood viscosity drops
• Angiotensin sensitivity drops

Question 5

When does BP return to normal during pregnancy?

Answer 5

Third trimester

Question 6

Why does urine output increase in pregnancy?

How does pregnancy affect U&Es?

Answer 6

Renal plasma flow and GFR increase

Serum Urea & Creatinine also decrease

Question 7

Why are pregnant women more at risk of UTIs?

Answer 7

Urinary stasis increases, in fact, hydronephrosis is even physiological come the 3rd trimester.
Making UTIs and pyelonephritis very common

Question 8

What is the major danger of a UTI to a pregnant woman?

Answer 8

Preterm labour.

So very important to treat them

Question 9

Why are pregnant women at risk of anaemia?

Answer 9

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.

Question 10

How does pregnancy affect blood cell counts?

Answer 10

WBC count increases slightly

Platelet count falls (due to rise in blood volume not loss of platelets)

Question 11

How does pregnancy affect the lungs?

How is PO2 affected?

Answer 11

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

Question 12

How does pregnancy affect the GI system?

Answer 12

GI motility is reduced, specifically:

Oesophageal peristalsis reduced

Gastric emptyin slows

Cardiac sphincter relaxes

Question 13

What hormones cause GI motility to be decreased in pregnancy?

Answer 13

• Increased Progesterone

- Decreased Motilin

Question 14

What are some normal symptoms of physiological changes in pregnancy? (i.e. symptoms mothers get in normal pregnancies?)

Answer 14

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

Question 15

Whats included in pre-preganancy counselling?

Answer 15

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

Question 16

When would you advise against pregnancy in pre-pregnancy counselling?

Answer 16

In certain conditions like Diabetes or Epilepsy

Question 17

Many maternal issues may recur in the next pregnancy, give 3 examples of these that are important in pre-pregnancy counselling?

Answer 17

Caesarean section
DVT
Pre-eclampsia

Pre-term delivery
Intrauterine growth restriction
Fetal Abnormality

Question 18

Whan can we do at pre-regnancy counselling to reduce the risk of previous problems recurring?

Answer 18

Thromboprophylaxis if h/o DVT aka low dose aspirin

Treat any infections
High dose folic acid to reduce abnormalities

Question 19

Whats involved in a routine antenatal exam?

Answer 19

• Feeling well?
• Feeling fetal movements (>20wks)
• BP
• Urinalysis
• Abdominal palapation
• Listen to fetal heart

Question 20

Abdominal palpation is an important part of an antenatal exam, what can it tell us?

Answer 20

• Fetal presentation
• Sympheseal Fundal height (SFH)
• Estimate baby size
• Estimate Liqour volume

Question 21

How do we determine which mothers to do antenatal screening on?

Answer 21

We dont.

We offer it to everyone but its not compulsory

Question 22

What is looked for on an Antenatal screen?

Answer 22

Blood screen:

• Hepatitis B
• Syphilis
• HIV
• Rubella
• Fe def anaemia
• Isoimmunisation i.e. Rhesus disease

MSSU for UTI

US scans for physical abnormalities:

• Down syndrome
• Neural Tube defects

Question 23

How do we treat if a basic antenatal screen throws up an infection in the mother?

Answer 23

Hep B give passive & active immunisation to baby

Syphilis give penicillin

HIV give maternal treatment to prevent vertical transmission

Question 24

How many US scans are women offered?

Answer 24

Offered one in the first and second trimester

Question 25

What is shown on a 1st visit US?

Answer 25

Is the pregnancy viable?
Single or multiple pregnancy?
Abnormalities incompatible with life

Question 26

When is down syndrome testing offered?

Answer 26

10-14 weeks gestation

Question 27

How do we initially test for Down’s Syndrome?

What results would indicate DS?

Answer 27

• Serum B-human Chorionic Gonadotrophin (Beta-hCG)
• Pregnancy associated plasma protein A (PAPP-A)
• Fetal Nuchal Translucency (NT)

Down syndrome is suggested by:
elevated B-hCG
decreased PAPP-A
thickened NT

Question 28

How does fetal nuchal translucency help identify Down’s Syndrome?

Answer 28

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.

Question 29

From initial tests how do we decide if a fetus requires further testing for Down syndrome?

Answer 29

Initial screening give a 1 in something risk of Down syndrome.

Further invasive tests are offered if risk is estimated at > 1in150

Question 30

If 1st trimester screening or 2nd trimester screening identify high risk of DS.

What further tests are available?

Answer 30

Chorionic Villus sampling (CVS) (10-14wks)
Amniocentesis (>15wks)
Non-invasive Prenatal Testing

These all have a small but significant risk of miscarriage (<1 -> 2%)

Question 31

How does Non-invasive prenatal testing for Down’s Work?

Answer 31

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)

Question 32

How do we screen for neural tube defects?

Answer 32

Part of the first trimester US, should pick up anencephaly & sometimes Spina bifida

Possibly 2nd trimester biochemical screening

2nd trimester US

Question 33

Why & how would we do 2nd trimester biochemical screening?

Answer 33

If we couldn’t get a NT measurement from the US

Take maternal serum alpha fetoprotein. >2MoM is high risk

Question 34

What does and doesnt show on a 2nd trimester US?

Answer 34

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

Question 35

In summary:

Answer 35

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