Applied Embryology

Question 1

What are the most common kinds of birth defects?

Answer 1

Congenital heart defects (6:1,000)

Neural tube defects (1:1,000)

Question 2

What are the two categories of teratogen?

Answer 2

Environmental exposure of mother during pregnancy

Genetic defect passed on by either parent

Question 3

What are the potential effects of teratogenicity?

Answer 3

• Intrauterine death
• Structural (congenital) malformations
• IUGR or growth defects
• Neurodevelopmental / behavioural dysfunction
• Developmental delay
• Carcinogenesis (exposing babies in-utero to X-rays can cause childhood leukaemia)

Question 4

When are structural and functional defects due to teratogenicity most likely to occur?

Answer 4

Structural defects- weeks 3-11

Functional defects- weeks 12 onwards

Question 5

By what triad is congenital rubella syndrome defined?

Answer 5

• Sensorineural deafness
• Eye abnormalities (retinopathy, cataracts, microphthalmia)
• Congenital heart disease (pulmonary artery stenosis, patent ductus arteriosus)

Question 6

What are the potential problems related to a double uterus?

Answer 6

• No effect
• Dysparunia/aparunia
• Infertility
• Abnormal lie in pregnancy/labour

Question 7

What is uterus didelphus?

Answer 7

Partial fusion of the uterine membranes, resulting in dimpling on the superficial aspect of the uterus