Flashcards in Obstetrics: Antenatal Deck (20):
What is obstetric cholestasis - how does it present, what are the risks and how is it managed?
The impaired flow of bile during pregnancy causes a build up of bile sats which can deposit in the skin and cause itching. The build up of bile salts can be detrimental to foetal wellbeing and the normal management is to induce labour at 37 weeks. Ursodeoxycholic acid is widely used as it vitamin K supplements.
What physiological changes occur in the cardiovascular system during pregnancy?
1. Stroke volume increases by 30%
2. Heart rate increases by 15%
3. Cardiac output increases by 40%
4. Diastolic BP is lowered in the first and second trimester and returns to normal by term
5. Enlarged uterus may interfere with venous return which causes ankle oedema, supine hypotension and varicose veins.
What physiological changes occur in the respiratory system during pregnancy?
1. Pulmonary ventilation increases by 40%
2. Tidal volume increases from 500ml to 700ml
3. Oxygen requirements increase by 20%
What physiological changes occur in the haematological system during pregnancy?
1. Maternal blood volume increases by 30% - red cells up by 20% but plasma up by 50% so the haemoglobin levels fall.
2. Rise in coagulation due to rise in fibrinogen and factors VII, VIII and X.
3. Platelet count falls
4. WCC and ESR rise
What bloods are done at the booking visit?
Blood group and antibodies
Random blood glucose
What is the normal schedule of midwife antenatal care?
Booking visit at 8 - 12 weeks
Dating USS and 11 - 12 weeks
Anomaly scan at 20 weeks
Monthly visits until 28 weeks
Anti D (if required) at 28 and 34 weeks
Fortnightly visits 28 - 36 weeks
Weekly visits 37 weeks until delivery
What examinations/investigations are done at every antenatal visit?
When would essential hypertension present in pregnancy compared to gestational hypertension?
Essential - Before 20 weeks
Gestational - After 20 weeks
What three anti - hypertensive are safe to be used in pregnancy?
3. Nifedipine (usually only if monotherapy fails)
What medications are used if a women presents with severe hypertension in pregnancy?
Labetalol (oral or IV)
What extra screening do women with diabetes get in pregnancy?
Detailed USS at 28, 32 and 36 weeks with extended cardiac views
Retinal screening every trimester
What BM and HBA1C should you be aiming for in pregnancy?
BM 4 - 6
HBA1C less than 6%
What clotting factors increase in pregnancy?
VII, VIII, X and fibrinogen
What investigation do you do for a suspected DVT in pregnancy?
Duplex US of lower limb
What is the management for a suspected/confirmed PE is pregnancy?
Low molecular weight heparin
Continued until 3 months after delivery or 6 months after treatment (whichever is longer) Heparin in stopped during labour
How do you manage hypothyroid in labour?
Increase levothyroxine by 25 - 50mcg in first trimester. Repeat TFTs every trimester
Does hyperthyroid get better or worse in pregnancy?
Worse in the first trimester due to HCG
Improvement in the second and third trimester
What is acute fatty liver of pregnancy?
A rare and life threatening complication of pregnancy that occurs in the third trimester or immediate period after delivery. It presents with nausea, vomiting, anorexia and abdominal pain. Jaundice and fever may also occur.
AST and ALT are raised as is bilirubin. There is also a high WCC and this can progress to DIC due to fat deposit in the microvasculature.
Treatment is to correct the fluid balance, electrolyte abnormaliites and DIC. It almost always requires a C section as the mother and fetus are both likely to be in distress
What do you do to the thyroxine dose during pregnancy?
Increase levothyroxine by 25 - 50mcg in first trimester
Repeat TFTs every trimester