Drugs and pregnancy Flashcards
What is the most common causes of birth defect?
Majority are unknown; out of the known,
1) Genetic transmission
2)Drugs and chemicals
3) Chromosomal aberration
What is the Baroness Cumberlege report?
Published in 2020 which identified the clinical areas where teratogenic harm occurred due to sodium valproate, Primodos and surgical mesh used to treat female incontinence.
What was identified in the Baroness Cumberlege report?
Dismissing patients’ voice
Failure of informed consent
Parents living with guilt
What is primodos?
Hormonal medication used to detect pregnancy that resulted in birth defects and shortened limbs.
What is chromosomal aberration?
Disorder with abnormal morphology or number of chromosomes.
What is the background risk of birth defects in all pregnancies?
All pregnancies begin with a risk of 3-5%, which decreases when a specific organ or limb is fully developed.
What is spontaneous abortion?
Abortion initiated by the body due to chromosomal or reproductive tract abnormalities, with a risk of 10-20%.
What is gestational age?
Begins with first day of last period.
What is an embryo?
Week 3->Week 8 of pregnancy
What is a foetus?
Week 9 to end of pregnancy.
When does organogenesis occur?
During the embryo period in the first trimester.
Which system is most at risk for birth defects throughout pregnancy?
CNS
What is a teratogen?
Any agent administered during pregnancy which causes a structural or functional abnormality to the foetus at any point in development.
How is teratogenicity established?
Requires large sample of affected foetus while in utero.
->Lack of data means patients are not advised to take medication unless necessary while pregnant.
What are the common teratogenic agents?
Infections
Alcohol, tobacco, cocaine
Physical agents
Chemicals
Maternal health factors
Which infections are commonly teratogenic?
Cytomegalovirus, herpes, toxoplasmosis, varicella
What are the teratogenic physical agents?
Hyperthermia
Ionising agents
What are the teratogenic chemicals?
Herbicides, industrial solvents
What is behavioural teratology?
The effect of teratogenic agents on the behaviour or functional adaptation of the child to its environment
What is the most commonly used teratogen?
Alcohol and smoking.
Alcohol increases the risk of spontaneous abortion and lower birth weight.
What is foetal alcohol syndrome?
Preventable birth defects due to alcohol consumption such as
Small head, flat midface and ear anomalies
Immature development of the brain and CNS so:
->Difficulty with attention and hyperactive behaviour
->Delays in developmental milestones
What is transplacental carcinogenicity?
Agent has no effect on mother but results in cancer of the offspring due to exposure via placenta. Diethylstilbestrol is synthetic oestrogen that increased risk of vaginal, testicular and cervical cancer in young people
What is mutagenicity?
Teratogenic agent induce two types of mutations:
Germ cell mutation- reduces fertility
Somatic cell mutation: increases cancer risk
How do teratogenic agents work?
They are dose dependent and typically synergestic. Time of exposure is important in the severity of harm. There is a lack of a placental barrier against drugs and risk depends on the individual variation of a drug’s pharmacokinetic metabolism.
How does alcohol consumption in women of childbearing age differ?
Older women drink more frequently
Younger women drink heavier and binge drink
What are the types of inheritance?
Mendelian inheritance and Polygenic inheritance
What is Mendelian inheritance?
Monogenetic inheritance from single gene change in a recognisable pattern such as dominant, recessive. It results in a genetically based malformation.
What is Poylgenic inheritance?
Phenotypic trait caused by combination of multiple genetics and/or environment , such as drug interaction susceptibility which is dependent on both the mother and foetus’ genetic constitution.
What is spina bifida?
Neural tube defect due to failure of the cranial and caudal neuropore to close in the second trimester, which can majorly be prevented via folic acid supplements.
What is the cause of spina bifida?
Unknown with no inherited links but family history increases risk.
Associated with single gene disorders or chromosomal aberrations for folate transport combined with environmental effect.
What increases risk for spina bifida?
Pre-gestational diabetes
Previous pregnancy of spina bifida with same partner
Low folate intake
Maternal obesity
Valproate and carbamezapine