OB-GYN Revision 7 Flashcards
How do you alter care for someone with hypothyroidism during pregnancy? [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.
How do you manage hypertension during pregnancy:
- which medicines should be stopped [3]
- which medicines can be continued [3]
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)
Which anti-epileptic drugs are safe in pregnancy? [3]
Levetiracetam, lamotrigine and carbamazepine are the safer anti-epileptic medication in pregnancy
Which anti-epileptic drugs are not safe in pregnancy? [2]
Why/ [2]
- Sodium valproate is avoided as it causes neural tube defects and developmental delay
-
Phenytoin is avoided as it causes cleft lip and palate
*
How does pregnancy alter PK of drugs? [4]
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
Name three drugs that have increased renal perfusion during pregnancy [3]
What is the clinical significance of this? [1]
Amoxicillin, Digoxin, Lithium
- Increased renal perfusion and elimination of drugs: cleared by the kidneys in pregnancy causes plasma levels to drop
Retinoids cause teratogenicity via which mechanism? [1]
Neural crest cell disruption
trimethoprim causes teratogenicity via which mechanism? [1]
When can / can’t trimethoprim be given during pregnancy? [1]
Folate antagonism
- not recommended in the first 12 weeks
A patient presents with these teeth - which drug was likely used during pregnancy to cause this? [1]
Tetracyclines
A patient presents with this problem - which drug was likely used during pregnancy to cause this? [1]
Phenytoin induced cleft palate
A baby is born like this - what was likely taken to cause this? [1]
Thalidomide
What is the dose of folic acid should take pre-conception for:
- healthy women [1]
- NTD, epilepsy, multiple pregnancy, SCD [1]
Start Folic Acid x 2-3 months pre-conception
400 micrograms/day – healthy women
5 milligrams/day - NTD, Epilepsy, Multiple pregnancy, sickle cell disease
Describe the effect of using tobacco during pregnancy [+]
Low birthweight,
microcephaly, facial clefts
Increased risks of placenta previa, placental abruption, ectopic pregnancy, and PPROM
Reduced fetal oxygenation resulting in IUGR
Excessive alcohol consumption usually defined as >[]g/day during pregnancy [1]
Excessive alcohol consumption usually defined as >80g/day
Describe the effects of alcohol consumption during pregnancy [2]
Associated with spontaneous miscarriage in first trimester, even with low levels of intake 1,2
Fetal alcohol syndrome with chronic exposure
Describe the effects / presentation of fetal alcohol syndrome [+]
- short palpebral fissure
- thin vermillion border/hypoplastic upper lip
- smooth/absent filtrum
- learning difficulties
- microcephaly
- growth retardation
- epicanthic folds
- cardiac malformations
Effects of cocaine during pregnancy? [5]
- spontaneous miscarriage
- Facial and skeletal anomalies
- Intestinal atresia
- Mental & growth retardation
- Placental abruption
Describe the effects of heroin, methadone or opiates during pregnancy [3]
- Placental vasoconstrictor so IUGR can occur
- Mental & growth retardation
- Placental abruption
Describe the treatment ladder for HG [4]
Hyperemesis gravidarum treatment dependent on severity: anti-emetics + thiamine 1.5mg od + Prednisolone 16mg od + Parental fluids + TPN1
Anti-acids during pregnancy - give examp;es of which are safe
- H2 antagonists [2]
- PPIs [1]
H2 antagonists:
- Cimetidine and Ranitidine are safe
PPIs:
- Omeprazole - however used only for protracted cases where the above haven’t been effective
Which analgesics are safe during pregnancy (include when they are / not safe w/ regards to gestation)
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
Which NSAID is preferred post-partum? [1]
Which opiod? [1]
Ibuprofen
Di-hydrocodiene or tramadol used at lowest dose for shortest duration
Which antifungals are safe [2] and unsafe [3]
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
Which of the following causes NTD and facial clefts during pregnancy
Rifampicin
Isoniazide
Ethambutol
Trimethoprim
Streptomycin
Which of the following causes NTD and facial clefts during pregnancy
Rifampicin
Isoniazide
Ethambutol
Trimethoprim
Streptomycin
Which of the following causes ototoxicty during pregnancy
Rifampicin
Isoniazide
Ethambutol
Trimethoprim
Streptomycin
Which of the following causes ototoxicty during pregnancy
Rifampicin
Isoniazide
Ethambutol
Trimethoprim
Streptomycin & other aminoglycosides
NB: Erythromycin safe
Which antibiotix drug class can cause dysplasia of bones if given during pregnancy? [1]
Tetracyclines
Which drugs are used to control hypertensive crises during pregnancy? [2]
IV labetalol or hydralazine are used to control hypertensive crises.
Which drug is used for severe pre-eclampsia and eclampsia? [1]
MgS
Which drugs are safe for gestation diabetes? [2]
Which should be avoided? [1]
Sulphonylureas can cause fetal hyperinsulinemia & neonatal hypoglycemia therefore best avoided
Metformin does not cross the placenta and is therefore safe in pregnancy.
Which anticoagulants are safe / unsafe during pregnancy?
DOACS:
- Unsafe - cause bleeding risk
Low molecular weight heparins (LMWH) are safe in pregnancy
Warfarin
- unsafe
What is the a potential risk of when give levothyroxine during pregnancy? [1]
Some suggested association with
unilateral kidney agenesis
Describe the cART rec. for pregnancy [3]
Which drug should be given during labour? [1]
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.
Which drugs can be used to supress lactation (e.g. after perinatal death) [2]
Carbergoline
- now first line
Bromocriptine
- is a dopamine receptor agonist thus inhibits prolactin release
What causes obstetric cholestasis? [2]
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).
Obstetric cholestasis is associated with an increased risk of [].
Obstetric cholestasis is associated with an increased risk of stillbirth.
What are the clinical features of intrahepatic cholestasis of pregnancy? [3]
- 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
How do you investigate for obstetric cholestasis? [1]
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.
How do you manage obstetric cholestatis? [4]
- 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)
What are the symptoms of polymorphic eruption of pregnancy? [4]
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.
How do you manage PMEP? [1]
Topical emollients
Topical steroids
Oral antihistamines
Oral steroids may be used in severe cases
During which trimesters of pregnancy does atopic eruption of pregnancy occur? [1]
What are the two types? [2]
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.
Describe what is meant by melasma [1]
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)
