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