Medicine in pregnancy Flashcards
What are the most significant causes of maternal deaths? (Unrelated to the pregnancy)
Cardiovascular
Neuro - mainly epilepsy
Mental health - maternal suicide
What are some important teratogenic drugs for common medical conditions that should be stopped?
Anti-epileptics - valporate
ALSO WHEN ARE THEY PARTICULARLY SENSITIVE E.G. TRIMESTER
What are common medical problems of pregnancy?
Anaemia - 2-3x increase in iron requirement = iron deficiency is most common, but also remember b12/folate (10-20x increase in requirement)
How do you investigate and manage iron deficiency anaemia in pregnancy?
Hb - low
MCV - microcytic (<76fl)
Ferratin - low
Management: oral iron supplements, check Hb again after 4-6wks, if no response - ?compliance or absorption issues - can give IV - response estimated within 1-2wks
Also consequences if untreated: low birth weight and premature delivery
How do you investigate and mange B12/folate deficiency anaemia?
Hb - low
MCV - macrocytic (>96fl)
Antibodies - checking for pernicious anaemia, Abs =
Folate - low
Vitamin B12/cobalamin - probably low (but also low in pregnancy anyway; also in those taking OCP)
Management: hydroxocobalamin 1mg IM 3x a week for 2wks; if not diet related - subsequently every 2-3m for life; if diet related - advise oral cyanocobalamin 50-150 micrograms daily between meals (for life in vegans) (or increase egg, cereal, meat, milk, salmon consumption)
How do you manage asthma in pregnancy?
Tend to have an exacerbation in 3rd trimester; adherence also an issue (as per)
Can continue to use all the drugs - SABA, ICS, oral steroids (though some risk of cleft palate if used in before 12wks), leukotriene receptor antagonists, theophylline
If poorly managed - poor maternal perfusion - risks of foetal growth restriction due to placental perfusion problems (at risk of premature delivery, especially if acutely deteriorating)
What are some cardiac risks during pregnancy?
Ischaemic disease is the most common cause of maternal death (congenital heart disease in younger women)
Low risk lesions:
Mitral + aortic incompetence
ASD + VSD
High risk lesions - (50% or more) Aortic stenosis Coarctation of the aorta Prosthetic valves - metal especially (as anti-coag) Cyanotic heart disease
May develop peripartum cardiomyopathy- late pregnancy-6m post delivery - increasing SOB, 25% will be hypertensive (DDx preeclampsia)- CXR/ECG
How do you manage cardiac risks drying pregnancy?
Cardiology before in high risk patients - FHx or PMHx
Monitor foetal growth and wellbeing
Pan for best timing and methods of delivery
Anticoagulation - e.g. if have metal valves - need switching from warfarin to a. LMWH e.g. dalteparin
Optimise existing drug treatment - various drugs are un/suitable at certain points: Ca channel blockers are generally well tolerated; labetalol and bisoprolol are fine (may cause foetal hypoglycaemia and bradycardia when used near term); furosemide okay, antiarrhythmics generally okay but little data
Contraindicated drugs: ACE inh, ARBs, spironolactone (foetal abnormalities)
What is the most common liver disease in pregnancy?
Obstetric cholestasis (unique to pregnancy)
Risks: genetics - Scandinavian, Chilean
Presentation: itching w/o rash, severe, affects limbs + trunk, especially soles and palms; usually during 3rd trimester
Investigation: raised AST, ALT and bile acid
Management: resolves after delivery; ursodeoxycholic acid - reduces itching but does nothing for foetal risk; also increases bleeding risk so possible vit K
Prognosis: Is associated with premature passage of meconium, still birth and premature labour - possibly due to high levels of bile acids; 80% recurrence risk
What are some features of hyperthyroidism in pregnancy?
Hyperthyroidism is rare, may improve after 1st trimester
Maternal risk = thyroid crisis with cardiac failure
Foetal risk = thyrotoxicosis due to thyroid stimulating antibodies
Antithyroid drugs - mostly use propylthiouracil (SE: maternal liver failure); carbimazole (foetal abnormalities)
If mother has stimulating antibodies - monitor foetal growth closely with USS
What are the features of hypothyroidism in pregnancy?
Common
Untreated may mean foetal loss and impaired neurodevelopment
Aim for adequate replacement with thyroxine before pregnancy or in first trimester
What are risks associated with diabetes during pregnancy?
Maternal: DKA hypoglycemia progression of retinopathy preeclampsia premature labour
Foetal:
miscarriage
macrosomia then increased risk of shoulder distocia/erbs palsy
Foetal abnormalities
unexplained still births - babies are delivered 2wks prior to due date (reduces this risk?)
hypoglycemia, ARDS
foetal complications - due to hyperglycaemia = teratogenic
How do you manage DM during pregnancy?
T1 - As would do without being pregnant, probably under close supervision of diabetic team
T2 - Metformin is fine, Glibenclamide is also okay but all other drugs for similar indications should not be used
No statins or ACE inhibitors
What are the risks of chronic renal disease in pregnancy?
Maternal: Severe hypertension Deterioration in renal function Preeclampsia C-section
Foetus: Premature delivery Growth restriction Stillbirth Abnormalities secondary to maternal drug therapies
What dictates outcome in chronic renal disease in pregnancy?
Degree of pre-pregnancy and intra-pregnancy renal dysfunction
Maternal BP, Creatinine levels and proteinuria
Monitored closely - maternal and foetal wellbeing
What are the features of epilepsy in pregnancy?
Increased risk of seizure frequency
Increased risk of sudden death - likely due to having to stop taking drugs or reluctance because of fears they will harm their baby during pregnancy or breastfeeding
What are the complications of maternal epilepsy for the child?
Neural tube defects/spina bifda and other abnormalities - risk mostly due to drugs taken but also possibly epilepsy itself
All anticonvulsants associated with risk of foetal abnormalities- sodium valproate has the highest risk = 7-9%; risks of: spina bifda, ASD, cleft palate, hypospadius, polydactyly, reduced IQ
Also risk of premature births
Maternal seizure links to foetal hypoxia (and subsequent problems)
May also inherit epilepsy depending on aetiology in mother
How do you manage epilepsy in pregnancy?
Risk assessments - balancing untreated epilepsy with risks of drugs on foetus
Plan delivery - avoid prolonged labour
Folic acid - high dose - 5mg OD for 1st 3m (at least)
Antiepiletics - lamotrigine, levetriacetam and carbamazepine are known to have the smallest effects on foetus; avoid phenytoin and valproate; refer to specialist
Antenatal - screening for abnormalities
What are the risks of thromboembolism in pregnancy?
Major cause of maternal death
Risk factors:
Normal physiological changes increase VTE risk throughout pregnancy = relative risk postpartum is 5x higher compared to antepartum; absolute risk peaks in the first 3wks postpartum which persists up to 6 weeks postpartum
Intermediate risk (2+ of the following): BMI >40 or >30 Operative delivery - C section Medical comorbidity e.g. heart failure, Ca, IBD, sickle cell etc Age >35yrs Smoker Current systemic infection Preterm or still birth or multiple foetus in this pregnancy >24hr labour etc...
High risk:
Previous VTE
Antenatal LMWH use
Hx of heritable thrombophilias e.g. Antithrombin deficiency
How do you manage thromboembolism in pregnancy?
Leg Doppler
CTPA
Dalteparin or other LMWH is treatment of choice for confirmed VTE - monitored with Anti-Xa activity
Warfarin not indicated as crosses placenta and may cause foetal abnormalities and intracranial bleeding
Should be initiated from 28wks and continued to 6wks post partum
If Dx made shortly before delivery - should remain on for 3m
How should you manage diabetes preconception?
Aim for HbA1c <48mmmol/L
Give folic acid - 5mg - reduces risk of neural tube defects
Stop ACE inhibitors and statins as teratogenic
Retinal screening and renal function monitoring (microalbuminaemia)
