drug use in pregnancy Flashcards
how many women develop problems during pregnancies?
- 10% of pregnant women have a chronic medical disorder
- 40% pregnant women develop problems during pregnancy
- 20% of pregnancies result in miscarriage before 12 weeks
- Spontaneous congenital malformations occur in 2 –3% of births in Europe
what is the pre-embryotic stage?
this is up to 17 days after conception
damage during this stage can lead to failed implantation and miscarriage
minor damage with a drug with a short half life can be corrected
damaged cells can be replaced by extra divison of the remaining cells
can go on to implant and develop normally
this is the first 12 weeks
what drugs can enter the foetal blood supply?
all drugs depending on the physiochemcial properties can cross the placenta
if drugs are lipid soluble/low mr they cross the placenta quicker
if they are ionised they cross slower
if they have a similar structure to endogenous hormones they also pass quicker
what are the two exceptions of the drugs that cannot cross the foetal drug supply?
heparins and insulin
what changes occur in the mother during pregnancy?
increased total body weight
increased liver metabolism
increased renal blood flow- doubles during pregnancy
increased plsama protein -reduced serum conc in drugs concentration
what are teratogens?
administration of a drug that can cause structural or functional abnormalities in the foetus or child after birth
what influences how much drug will reach the foetus?
maternal plasma levels half life mr transfer of similar agents presence or absence of placental metabolising enzymes
how do we decide if there is a teratogenic risk?
does the drug cause toxicity in animals at lower doses
dose the drug cross the human placenta
is their human pregnancy experience of exposure to similar agents
is their human pregnancy experience of exposure to the drug itself
what are the probelems associated with drug trials in pregnancy?
pregnant women are excluded from clinical trials
predicting what will happen from the info we have from similar drugs is often impossible
when should you prescribe in pregnancy?
if benefit outweighs the risk
avoid 3rd trimester where possible
use drugs with extensive use
prescribe lowest dose for shortest time
what does absence of information mean?
does not imply the medication is safe
what is advised when preparing for pregnancy?
to plan your pregnancy
know that you are fit for pregnancy as it is thought that the health of the mother/ father can influence the childs health
how do you prepare for pregnancy’s?
- Healthy eating
- Ideal weight
- Supplements–Folic Acid
- Smoking cessation
- Alcohol consumption
- Drug misuse
- Existing medical conditions
- Vaccinations •Cervical and STI Screening
how can a healthy diet influence your baby?
- Your diet prior to pregnancy can affect your baby’s development
- Healthy diet and moderate exercise are advised to maintain/obtain an IBW
- Eat high fibre foods, fruit and vegetables, avoid saturated fats and sugary foods and drinks
what is the ideal body weight? what are the cosequences of not being within this range?
Aim for a BMI between 18.5 and 24.9
•Being overweight (BMI >25) or obese (BMI >30) can cause difficulty in becoming pregnant and raises risks during pregnancy
why should folic acid be taken during pregnancy?
help prevent neural tube defects
ideally 3 months before conception
400mcg daily
what are the neural tube defects that can be caused?
spina bifida
anencephaly
encephalocele
what effects does smoking have on birth?
–Reduced fertility–Increased risk of:•Miscarriage •Stillbirth •Premature birth •Low birth weight •Complications during labour •SIDS
what smoking sensation is offered to pregnant women?
try to stop without NRT- use CBT
offer NRT if failed to quit without it
DO NOT prescribe bupropion or barenicline
aim to have stopped before conception
smoking causes a reduction in blood flow to baby for aprox 15 min
we use intermitting -gum etc
if using patch take off before bed
when should a 5mg dose of folic acid be given?
with eplipsy/ cealic disease
why is alcohol not recommended during pregnancy?
do not drink alcohol at all in the first 3 months, increased risk of miscarriage
avoid alcohol
this is due to risk of fetal alcohol syndrome
what are the signs and symptoms of fetal alcohol syndrome?
microcephaly short palpebral flat midface indistinct phitrum thin upper lip epicanthal low nasal bridge minor ear abnormalities short nose micrognathia
what is recommended with ilicit drug use in pregancny?
seek help to quid prior to concepion
what is the effects of taking methadone during pregnancy?
no increase in congenital defects
low birth weight
neonatal withdrawl symptoms
respiratory depression is not a signifigant probelm
what are the symptoms of withdrawl syndrome from ilicit drug use?
high pitch cry
passing small amounts of urine
general distress
what are the risk of patients with IV drug use history ? illicit
risk of HEP b/c
what is checked in a preconception check up?
checks general health before having a baby
-long term medical conditions e.g. diabetes, asthma, hpt, eplipesy
cervical/STI screening
ensure your vaccinations are up to date
what is the recommended calorie intake for the last trimester of pregnancy?
an extra 200 calories- e.g. two more bananas
what should vegans/ vegitarians do when pregnant?
need to maintain iron and b12- take supplements
what should be avoided in a diet in pregnany?
Vitamin A supplements and food high in vitamin A –Unpasteurised milk and cheese–Ripened soft cheese–Raw/partially cooked eggs–Caffeine–Certain seafood
what supplements should be taken during pregnancy?
folic acid- help to prevent tube defects- 400mcg daily
high risk take 5mg
vit D- 10mcg daily
what vaccinations are needed during pregnancy?
tdap between 27 and 36 weeks-prevention of whopping cough
travel vaccinations- avoid unless necessary
influencza- recommended
other eg hep A/B meningococcal- live vaccines can cause harm to baby - take before conception a good while before
how can nausea and vomiting be managed in pregnancy?
usually resolves within 16-20 weeks
thought to be due to an increase in oestrogen
can be distrubances if lot of electrolytes lost
can use -ginger/ acupuncture bands
antiemetics-unlicensed- cyclizine- 50mg 3x a day
promethazine at night
review after 24 hours
what are some lifestyle measures that can be taken for nausea and vomiting?
–Adequate hydration–Eat small meals–Avoid triggers–Avoid spicy food and caffeine–Prevent fatigue
what should be done in extreme causes of nausea and vomiting? hyperemesis gravidarum
–Severe vomiting –Dehydration and weight loss–May require admission to hospital•Fluid replacement•Electrolyte replacement•Medication
is heartburn commen in pregnancy? what treatment should be given?
–80% of women develop heartburn–1stline: verbal and written lifestyle advice
•Small, frequent meals, don’t eat within 3 hours of going to sleep, avoid irritant
–2ndline: antacids and alginates
•Gaviscon Advance®, Peptac®
–3rdline: acid suppressing medications•Ranitidine, Omeprazole
how should constipation be treated in pregnancy?
–Dietary measures–Adequate fluid intake–Exercise–Review medication–Laxatives
•1stchoice: bulk forming
•2ndchoice: lactulose or macrogol
why does increased urinary frequency occur?
•Due to hormone changes, pressure on the bladder from the uterus and relaxation of the pelvic floor muscle•Can be one of the first signs of pregnancy
what symptoms should you look for in increased urinary frequency?
–Pain–Blood–Discomfort in pelvis–Back pain–Increased temperature–Nausea/vomiting–Cloudy, foul-smelling urine
what should be done if a woman develops a UTI when pregnant?
•Treatment should be guided by urine culture and sensitivity–Often initiate antibiotics before available•Choice depends on patient allergies, trimester–Antibiotics should continue for 7 days–Avoid OTC alkalinising agents
what treatment should be given to a pregnant women for UTI in the first trimester?
•Trimethoprim–First trimester–Folate antagonist–Cardiovascular defects–Neural tube defects–Oral clefts–Hyperbilirubinaemia–Kernecticus
what are the s/e of trimethroprim to be aware of?
jaundice
kernicterus
what causes jaundice?
excess bilirubin in blood
what causes kernicterus?
bilirubin moves from blood stream into brain tissue
what are alternate treatment options for UTI?
Nitrofurantoin
•Penicillin’s
•Cephalosporins
why does thrush occur in pregnancy?
can occur due to increased oestrogen levels during pregnancy
how do you treat thrush in pregnancy?
–Topical clotrimazole is safe during pregnancy–Oral therapy is contra-indicated
can give pessary for 7 days- careful when using applicator
generl advise- shower over bath
use unscented products
why do you avoid stimulant laxatives in pregnancy?
can cause contractions - maybe pre-mature labour
what advise would you give for a backache?
exercise in water/ massage therapy
pain control- paracetamol/ opioids/ NSAIDs/ non-pharmacological options
why are NSAIDs usually avoided?
- Block blastocyte implantation
- Patent ductus arteriosus
- Persitent pulmonary hypertension of the neonate if used in 3rdtrimester
- Inhibit labour and prolong pregnancy
- Cardiac defects
- Cleft palates
what is patent ductus arteriosus?
abnormal circulation in heart
what advise would you give for cramps in pregnant women?
Lifestyle measures •Adequate hydration •Adequate diet/supplements •Massage the area •Foot and calf exercises •Comfortable, well fitted shoes •Warm bath in the evening
watch for: persistant pain, swelling, redness, warmth- dvt
what advise would you give for swollen extremities?
can develop swollen feet, ankles, legs and fingers
General advice–Adequate hydration
–Avoid standing for long periods of time–Leg/calf exercise–Good shoes
watch for DVT
what advise would you give for itching skin?
–Adequate hydration–Loose cotton clothes–Emollients
–Severe itching especially on hands and soles of feet–Intrahepatic cholestasis of pregnancy
how can anaemia occur in pregnancy? what are the symptoms?
- Haemoglobin in your blood is lower than normal.
- Iron deficiency is the most common cause in pregnancy
- Signs and symptoms–Shortness of breath–Poor concentration–Poor appetite–Muscle weakness
how should you treat anaemia in preganacy?
- Monitor Hb•NICE: treat women whose Hbis <11g/dl at booking and <10.5g/dl at 28 weeks
- Treatment–Oral: Ferrous Sulphate 200mg TDS–IV: Ferinject® (in some cases)
what are the signs and symptoms of VTE?
–DVT
•Unilateral leg swelling•Red, warm, tender and painful–
PE
•Sudden unexplained difficulty in breathing•Chest pain•Haemoptysis
how should VTE be treated?
–LMWH
•Tinzaparin
•Dalteparin
•Enoxaparin –Use booking weight to determine dose–Do not use warfarin or DOAC’s
what can happen if you treat VTE with warfarin?
Foetal warfarin syndrome–Nasal hypoplasia–Upper airways obstruction–Other abnormalities–Critical period 6-9 weeks gestation–2ndand 3rdtrimester–Risk of foetal and neonatal haemorrhage
what are the risk factors for gestational diabetes?
–BMI >30Kg/m2–Previous gestational diabetes–Family history of diabetes (1stdegree relative)–Family origin
what is the cause of gestational diabetes>
–Thought to be associated with excess weight before pregnancy
–Hormone levels change during pregnancy, this can result in insulin resistance, insufficient insulin being produced
How is gestational diabetes picked up in pregnancy? what tests are done?
–A risk assessment is done at your first midwife appointment –if you have 1 or more risk factors for developing GD you are offered a glucose tolerance test •Between 24 –28 weeks•Women need to fast prior to the test (8 –10 hours)•Given 75g of glucose drink
•Bloods rechecked after 2 hours
what are the signs and symptoms of gestational diabetes?
–Some women don’t notice any–Increased thirst–Increased urinary frequency–Dry mouth–Tiredness
how is gestational diabetes managed?
- Diet and exercise
- Oral hypoglycaemic agent–Metformin–Glibenclamide
- Insulin
how should a woman monitor her gestational diabetes?
–Women will need to monitor their blood sugars
–Following a diagnosis pregnant women often get more input to their care e.g. increased scans and consultant appointments
–May require more input during birth
what are the complications that may occur due to gestational diabetes?
–Larger than usual baby–Premature birth (< 37 weeks)–Pre-eclampsia–Complications with the baby–Still birth
what needs to be done in gestational diabetes after birth?
–Women will need to have their blood sugar levels checked 6 –13 weeks after having their baby
how would one diagnose gestational hpt?
Sustained blood pressure greater than or equal to 140/90mmHg in a previously normotensive patient (no proteinuria)
how would you manage gestational diabetes?
- Hyperension(140/90 –159/109mmHg)–Treat with labetolol–aim for BP of 135/85mmHg–Measure BP once/twice a week
- Severe(>160/110mmHg)–Admit to hospital–Treat with labetolol-aim for BP of 135/85mmHg–Measure BP every 15 0 30 minutes until BP less than 160/110 mmHg
what is pre-eclampsia?
Rapidly progressive condition characterised by high blood pressure and proteinuria
who is at high risk of developing pre-exlampsia?
–Hypertensive disease during a previous pregnancy–Chronic kidney disease–Autoimmune diseases–Type 1 or 2 diabetes–Chronic hypertension
what medication should be given to those at high risk of pre-eclampsia?
At high risk –aspirin 150mg daily from 12 weeks until birth
What are the signs and symptoms of pre-eclampisa?
weight gain- more than 5 pound in one week elevated bp swelling of face eyes and hands difficulty breathing, gasping or panting changes in vision nausa headache that wont go away
what is the treatment for pre-eclampsia?
hpt: 140/90- 159/109
–Admit if any clinical concerns–Monitor BP every 2 days–1stline: labetalol
Severe (BP 160/110 mmHg or more)–Admit to hospital–Monitor BP every 15 –30 minutes initially–Consider if referral to level 2 critical care is required
