Applied Embryology Flashcards
What are the most common developmental anomalies?
Congenital heart defects
How many babies are affected by congenital heart defects?
At least 6 in every 1,000
What percentage of babies with a heart defect die before their first birthday?
6%
How many babies are affected by neural tube defects such as spina bifida?
1 in 1000
How many babies are born with a birth defect?
1 in 46 - this ranges from birthmarks to serious congenital anomalies
What are teratogens?
An exposure e.g. a drug, substance or infection, to which the mother is exposed during pregnancy
What can teratogens cause?
Structural or functional abnormalities
In-utero death
What are some manifestations of teratogen exposure?
Intra-uterine death Structural malformations IUGR or growth defects Neurodevelopmental or behavioural dysfunction Developmental delay Carcinogenesis
What does the manifestation of teratogen exposure depend on?
The teratogen
Time at which foetus is exposed
Mother’s susceptibility
When is there the greatest risk of structural defects caused by teratogens occurring?
Between weeks 3 and 11, when organogenesis is occurring
When are functional or growth defects more likely?
After 12 weeks gestation
List some teratogens
Thalidomide Carbamazepine Sodium valproate Retinoids e.g. Roaccutane Doxycycline Alcohol Smoking Illicit drugs
What are the rules regarding retinoid treatment in women of childbearing age?
Women of childbearing age who are prescribed retinoids must be on contraception due to potential teratogenicity - when used in treatment of acne, monthly pregnancy tests may also be carried out
What are some of the potential teratogenic effects of retinoids on the foetus?
Absent ears Microphalthmia Cardiac anomalies Microcephaly Cleft lip and palate Nervous system abnormalities
Exposure to diethylstilbestrol in utero is thought to increase the risk of what?
Developing clear cell cancer of the vagina and cervix
Increased risk of breast cancer
