Applied Embryology Flashcards
How many babies have a birth defect?
1 in 46 babies
Problems with implantation
May not implant at all
May get stuck in ovary or tube or abdominal cavity
How many babies are affected by neural tube defects?
1 in 1000 babies
Definition of teratogen
An environmental ‘exposure’ (e.g. a drug or substance or infection) to which the mother is exposed to during pregnancy. May detrimentally affect the embryo/foetus in utero, may lead to structural or functional abnormalities or even in utero death
Effects of teratogens on the developing foetus
Death Cancer IUGR/growth defects learning difficulties sensory deficit structural abnormalities neurodevelopmental/behavioural dysfunction developmental delay
When can teratogenic exposure occur?
Pre-conception First trimester Second trimester Third trimester Post partum
When is the biggest risk for organogenesis?
weeks 3-11
When is the most likely time to get functional or growth defects?
After 12 weeks gestation
What does thiamolide cause?
Limb defects
What does sodium valproate cause?
Neural tube defects
What does carbamazepine cause?
Facial feature defects
Isotretinoin is used for…
Severe cystic acne
Isotretinoin causes….
microphlamia absent ears cardiac anomalies microcephaly cleft lip and palate NS anomalies
What does tetracycline cause?
Problems with teeth (it is not lethal)
What is diethylstilboestrol for?
Non-steroidal oestrogen which was given to women to prevent miscarriage
What does diethylstiboestrol cause?
Increased risk of developing clear cell cancer of the vagina and cervix in later childhood/teen
How many units of alcohol can cause foetal alcohol syndrome?
more than 8 units a day
Binge drinking definition
5 or more units of alcohol on one occassion
Cigarette smoking in pregnancy results in…..
pre-eclampsia small babies pre-term labour stillbirth miscarriage
Triad for congenital rubella syndrome
- Sensorineural deafness
- Eye abnormalities (retinopathy cataract and microphthalmia)
- Congenital heart defects (PAS and PDA)
Varicella (chicken pox) causes….
Limb hypoplasia
Skin scarring
Eye defects
When is the greatest risk of varicella (chicken pox)?
2nd trimester
What causes respiratory depression in neonates?
Opiate medications taken for maternal pain relief in labour
Pre-conception counselling is vital to offer to…
Epilepsy Diabetes Women on anticoagulants Women with congenital anomalies Antihypertensives
Which women are at risk of NT defects?
Previous child with NTD DM Women on anti-epileptic medication Obese (BMI > 30) HIV +ve taking co-trimoxazole Sickle cell
