Embryo pt.6 Flashcards
What are some viruses that are known to cause congenital abnormalities?
- CMV
- Hepatitis B
- HSV
- Rubella virus
- Human parvovirus B19
- Syphilis
- Varicella virus
- Zika virus
What are some known agents that can cause congenital abnormalities?
- Alcohol
- Cocaine
- Tetracycline
- Warfarin
- Lithium carbonate
- Isotretinoin
- Androgens and high doses of progestogens
- Misoprostol
- Methotrexate
What is the most famous pharmaceutical catastrophe that led to the development of congenital defects in babies?
Thalidomide induced embryopathy
What can teratogens be divided into? Expand on each
Four categories:
- Physical (ionizing radiation and agents that contribute to hyperthermia)
- Chemical (metabolic conditions, malnutrition, diabetes, thyroid disorders)
- Infectious agents
- Maternal conditions (drugs and chemicals the pregnant female ingests such as alcohol, cocaine,
thalidomide; etc)
What was thalidomide prescribed for historically?
- Originally intended as a sedative
- Soon after used for treating a wide range of conditions including colds, flu, nausea, and morning sickness in pregnancy
- Scientists did not know that the effects of a drug could be passed through the placental barrier and affect development and so harm a fetus
When was thalidomide most use historically?
Thalidomide was a widely used over-the-counter drug in the late 1950s and early 1960s
What is the name of the condition in which a baby is developmentally affected by thalidomide use?
Thalidomide embryopathy
Chorioretinitis
An inflammation of the choroid, which is a lining of the retina deep in the eye
Definition of thalidomide embryopathy
A group of anomalies presented in infants as a result of in utero exposure (between 20-36 days after fertilization) to thalidomide
Characteristics of thalidomide embryopathy
- The most characteristic defects are reduction
deformities, that is, the loss of part or the
whole of one or more bones - Malformation of the limbs were commonly present (amr description: “the defect which falls just short of
complete absence of the arm (upper limb amelia) consists of one or more digits attached
directly to the shoulder)” - The majority of people with thalidomide defects of the upper limbs have normal lower
limbs - A minority have defects of all limbs
- Phocomelia (malformations of arms and legs)
- malformations of human arms and legs
- defects involving the
ears, the eyes, and the nerve supplies to the
face, the eye muscles, and the lacrimal (tear)
glands - Internal defects commonly affected the
heart, the kidneys and urinary tract, the alimentary tract, and the genital tract, and none
was unique to thalidomide
How many babies were affected by thalidomide embryopathy?
Estimates range from 10,000 to 20,000
Infant mortality from thalidomide embryopathy
Estimated to be as high as 40%.
Fetal alcohol deficiency features
- Mental deficiency
- Microcephaly
- Ocular anomalies
- Joint abnormalities
- Short palpebral fissures
- Intrauterine growth restriction
Chemicals causing birth defects
Methylmercury
Methylmercury associated birth defects
- Cerebral atrophy
- Seizures
- Mental deficiency
- Spasticity
