OB-GYN Revision 7

Question 1

How do you alter care for someone with hypothyroidism during pregnancy? [1]

Answer 1

Untreated or under-treated hypothyroidism in pregnancy can lead to several adverse pregnancy outcomes, including miscarriage, anaemia, small for gestational age and pre-eclampsia.

Levothyroxine can cross the placenta and provide thyroid hormone to the developing fetus. The levothyroxine dose needs to be increased during pregnancy, usually by at least 25 – 50 mcg (30 – 50%).
- Treatment is titrated based on the TSH level, aiming for a low-normal TSH level.

Question 2

How do you manage hypertension during pregnancy:
- which medicines should be stopped [3]
- which medicines can be continued [3]

Answer 2

Medications that should be stopped as they may cause congenital abnormalities:
* ACE inhibitors (e.g. ramipril)
* Angiotensin receptor blockers (e.g. losartan)
* Thiazide and thiazide-like diuretics (e.g. indapamide)

Continued:
* Labetalol (a beta-blocker – although other beta-blockers may have adverse effects)
* Calcium channel blockers (e.g. nifedipine)
* Alpha-blockers (e.g. doxazosin)

Question 3

Which anti-epileptic drugs are safe in pregnancy? [3]

Answer 3

Levetiracetam, lamotrigine and carbamazepine are the safer anti-epileptic medication in pregnancy

Question 4

Which anti-epileptic drugs are not safe in pregnancy? [2]
Why/ [2]

Answer 4

• Sodium valproate is avoided as it causes neural tube defects and developmental delay
• Phenytoin is avoided as it causes cleft lip and palate
  *

Question 5

How does pregnancy alter PK of drugs? [4]

Answer 5

Slow gastric emptying and reduced absorption of drugs

Increased maternal plasma volume: causes lowered serum levels of drugs making them ineffective eg anticonvulsants

Increased maternal hepatic metabolism: causes plasma levels of drugs to fall

Increased renal perfusion and elimination of drugs: cleared by the kidneys in pregnancy causes plasma levels to drop

Question 6

Name three drugs that have increased renal perfusion during pregnancy [3]

What is the clinical significance of this? [1]

Answer 6

Amoxicillin, Digoxin, Lithium
- Increased renal perfusion and elimination of drugs: cleared by the kidneys in pregnancy causes plasma levels to drop

Question 7

Retinoids cause teratogenicity via which mechanism? [1]

Answer 7

Neural crest cell disruption

Question 8

trimethoprim causes teratogenicity via which mechanism? [1]

When can / can’t trimethoprim be given during pregnancy? [1]

Answer 8

Folate antagonism
- not recommended in the first 12 weeks

Question 9

A patient presents with these teeth - which drug was likely used during pregnancy to cause this? [1]

Answer 9

Tetracyclines

Question 10

A patient presents with this problem - which drug was likely used during pregnancy to cause this? [1]

Answer 10

Phenytoin induced cleft palate

Question 11

A baby is born like this - what was likely taken to cause this? [1]

Answer 11

Thalidomide

Question 12

What is the dose of folic acid should take pre-conception for:
- healthy women [1]
- NTD, epilepsy, multiple pregnancy, SCD [1]

Answer 12

Start Folic Acid x 2-3 months pre-conception
 400 micrograms/day – healthy women
 5 milligrams/day - NTD, Epilepsy, Multiple pregnancy, sickle cell disease

Question 13

Describe the effect of using tobacco during pregnancy [+]

Answer 13

Low birthweight,
microcephaly, facial clefts

Increased risks of placenta previa, placental abruption, ectopic pregnancy, and PPROM

Reduced fetal oxygenation resulting in IUGR

Question 14

Excessive alcohol consumption usually defined as >[]g/day during pregnancy [1]

Answer 14

Excessive alcohol consumption usually defined as >80g/day

Question 15

Describe the effects of alcohol consumption during pregnancy [2]

Answer 15

Associated with spontaneous miscarriage in first trimester, even with low levels of intake 1,2

Fetal alcohol syndrome with chronic exposure

Question 16

Describe the effects / presentation of fetal alcohol syndrome [+]

Answer 16

• short palpebral fissure
• thin vermillion border/hypoplastic upper lip
• smooth/absent filtrum
• learning difficulties
• microcephaly
• growth retardation
• epicanthic folds
• cardiac malformations

Question 17

Effects of cocaine during pregnancy? [5]

Answer 17

• spontaneous miscarriage
• Facial and skeletal anomalies
• Intestinal atresia
• Mental & growth retardation
• Placental abruption

Question 18

Describe the effects of heroin, methadone or opiates during pregnancy [3]

Answer 18

• Placental vasoconstrictor so IUGR can occur
• Mental & growth retardation
• Placental abruption

Question 19

Describe the treatment ladder for HG [4]

Answer 19

Hyperemesis gravidarum treatment dependent on severity: anti-emetics + thiamine 1.5mg od + Prednisolone 16mg od + Parental fluids + TPN1

Question 20

Anti-acids during pregnancy - give examp;es of which are safe
- H2 antagonists [2]
- PPIs [1]

Answer 20

H2 antagonists:
- Cimetidine and Ranitidine are safe

PPIs:
- Omeprazole - however used only for protracted cases where the above haven’t been effective

Question 21

Which analgesics are safe during pregnancy (include when they are / not safe w/ regards to gestation)

Answer 21

Paracetamol
- safe

Aspirin
- Best avoided in late pregnancy as labour delayed and prolonged and increased risk of maternal and fetal
haemorrhage

NSAIDs
- Avoid in general: causes closure of PDA, NEC & pulmonary hypertension

Opoids:
- in general safe in short term use
- If on long term opioids inform neonatal team at delivery- risk of neonatal withdrawal

Question 22

Which NSAID is preferred post-partum? [1]
Which opiod? [1]

Answer 22

Ibuprofen
Di-hydrocodiene or tramadol used at lowest dose for shortest duration

Question 23

Which antifungals are safe [2] and unsafe [3]

Answer 23

Topical imidazoles (e.g. clotrimazole; econazole):
- Safe as poorly absorbed

Systemic antifungal (e.g. fluconazole,griseofulvin, terbinafine)
- unsafe
- Avoid pregnancy for at least 6 months after treatment completed

Question 24

Which of the following causes NTD and facial clefts during pregnancy

Rifampicin
Isoniazide
Ethambutol
Trimethoprim
Streptomycin

Answer 24

Which of the following causes NTD and facial clefts during pregnancy

Rifampicin
Isoniazide
Ethambutol
Trimethoprim
Streptomycin

Question 25

Which of the following causes ototoxicty during pregnancy

Rifampicin
Isoniazide
Ethambutol
Trimethoprim
Streptomycin

Answer 25

Which of the following causes ototoxicty during pregnancy

Rifampicin
Isoniazide
Ethambutol
Trimethoprim
Streptomycin & other aminoglycosides

NB: Erythromycin safe

Question 26

Which antibiotix drug class can cause dysplasia of bones if given during pregnancy? [1]

Answer 26

Tetracyclines

Question 27

Which drugs are used to control hypertensive crises during pregnancy? [2]

Answer 27

IV labetalol or hydralazine are used to control hypertensive crises.

Question 28

Which drug is used for severe pre-eclampsia and eclampsia? [1]

Answer 28

MgS

Question 29

Which drugs are safe for gestation diabetes? [2]

Which should be avoided? [1]

Answer 29

Sulphonylureas can cause fetal hyperinsulinemia & neonatal hypoglycemia therefore best avoided

Metformin does not cross the placenta and is therefore safe in pregnancy.

Question 30

Which anticoagulants are safe / unsafe during pregnancy?

Answer 30

DOACS:
- Unsafe - cause bleeding risk

Low molecular weight heparins (LMWH) are safe in pregnancy

Warfarin
- unsafe

Question 31

What is the a potential risk of when give levothyroxine during pregnancy? [1]

Answer 31

Some suggested association with
unilateral kidney agenesis

Question 32

Describe the cART rec. for pregnancy [3]

Which drug should be given during labour? [1]

Answer 32

tenofovir DF or abacavir with emtricitabine or lamivudine as a nucleoside backbone.

During labour, zidovudine should be administered intravenously until the umbilical cord is clamped.

Question 33

Which drugs can be used to supress lactation (e.g. after perinatal death) [2]

Answer 33

Carbergoline
- now first line

Bromocriptine
- is a dopamine receptor agonist thus inhibits prolactin release

Question 34

What causes obstetric cholestasis? [2]

Answer 34

result of increased oestrogen and progesterone levels
- In obstetric cholestasis, the outflow of bile acids is reduced, causing them to build up in the blood, resulting in the classic symptoms of itching (pruritis).

Question 35

Obstetric cholestasis is associated with an increased risk of [].

Answer 35

Obstetric cholestasis is associated with an increased risk of stillbirth.

Question 36

What are the clinical features of intrahepatic cholestasis of pregnancy? [3]

Answer 36

• pruritus - may be intense - typical worse palms, soles and abdomen
• clinically detectable jaundice occurs in around 20% of patients
• raised bilirubin is seen in > 90% of cases
• pale greasy stools

NB: no rash present

Question 37

How do you investigate for obstetric cholestasis? [1]

Answer 37

Abnormal liver function tests (LFTs), mainly ALT, AST and GGT
Raised bile acids

TOM TIP: It is normal for alkaline phosphatase (ALP) to increase in pregnancy. This is because the placenta produces ALP. A rise in ALP without other abnormal LFT results is usually due to placental production of ALP, rather than liver pathology.

Question 38

How do you manage obstetric cholestatis? [4]

Answer 38

• induction of labour at 37 weeks is common practice but may not be evidence based
• Emollients (i.e. calamine lotion) to soothe the skin
• ursodeoxycholic acid - again widely used but evidence base not clear
• vitamin K supplementation if clotting deranged (A lack of bile acids can lead to vitamin K deficiency, which lead to impaited clotting)

Question 39

What are the symptoms of polymorphic eruption of pregnancy? [4]

Answer 39

Lesions are pruritic but spare the periumbilical region, face, and mucosal surfaces:
* Urticarial papules (raised itchy lumps)
* Wheals (raised itchy areas of skin)
* Plaques (larger inflamed areas of skin)

Systemic symptoms are absent.

Question 40

How do you manage PMEP? [1]

Answer 40

Topical emollients
Topical steroids
Oral antihistamines
Oral steroids may be used in severe cases

Question 41

During which trimesters of pregnancy does atopic eruption of pregnancy occur? [1]
What are the two types? [2]

Answer 41

first and second trimester of pregnancy:

E-type, or eczema-type:
- with eczematous, inflamed, red and itchy skin, typically affecting the insides of the elbows, back of knees, neck, face and chest.

P-type, or prurigo-type:
- with intensely itchy papules (spots) typically affecting the abdomen, back and limbs.

Question 42

Describe what is meant by melasma [1]

Answer 42

Increased pigmentation to patches of the skin or face

No active treatment is required if the appearance is acceptable to the woman. Management is with:

Avoiding sun exposure and using suncream
Makeup (camouflage)
Skin lightening cream (e.g. hydroquinone or retinoid creams), although not in pregnancy and only under specialist care
Procedures such as chemical peels or laser treatment (not usually on the NHS)