Congenital disorders Flashcards
What percentage of live births in South Africa is affected by a physical or functional congenital disorder?
One in every 15 live births (6.8%).
How many physical disorders should be easily recognizable on day one of life?
About 25% of physical disorders.
What percentage of deaths in children younger than five years of age are attributed to congenital disorders?
4%
What is noted about the burden of long-term disability and care associated with congenital disorders?
The burden is significant.
How should external abnormalities be managed at birth?
They should be noted and recorded at birth.
How can congenital physical disorders be classified?
Congenital physical disorders can be classified as:
- A single defect alone.
- A single defect (initiating factor) resulting in a sequence of problems.
- Multiple abnormalities resulting from two or more separate defects.
What is a malformation sequence in congenital physical disorders?
It involves abnormal tissue formation, such as the Pierre Robin sequence, characterized by a small chin and cleft palate due to the posterior positioning of the tongue.
Describe a deformation sequence in congenital physical disorders.
It involves normal tissue being acted on by an external force. An example is the oligohydramnios deformation sequence, resulting in clubbed feet, a flat face, and a hypoplastic chest due to being squashed in the uterus.
What characterizes a disruption sequence in congenital physical disorders?
It involves the destruction of previously normal tissue, as seen in amniotic bands amputating fingers and toes.
What characterizes abnormalities resulting from multiple defects in congenital physical disorders?
These are usually syndromes, such as Down syndrome and fetal alcohol syndrome, which present with abnormalities of the heart, face, and brain.
What are some hereditary causes of congenital disorders?
Hereditary causes include sex-linked, dominant or non-recessive genetic disorders, or multifactorial conditions.
Provide an example of a non-hereditary cause of congenital disorders.
Trisomy 21, caused by non-disjunction in older mothers, is an example of a non-hereditary cause.
Name some infections that can lead to congenital disorders.
Infections such as cytomegalovirus (CMV), rubella, and toxoplasmosis.
What role do drugs play in the etiology of congenital disorders?
Drugs like alcohol, warfarin, and anticonvulsants can contribute to congenital disorders.
How can maternal illness impact the development of congenital disorders?
Maternal illnesses such as diabetes can affect fetal development and lead to congenital disorders.
What is the status of the etiology of congenital disorders for the majority of cases?
For the majority of cases, the etiology remains unknown.
Aetiology of congenital disorders
- hereditary
- non- hereditary
- infections
4.drugs - maternal illness
- unknown
indications for increased vigilance of early diagnosis of congenital disorders
- Family history of hereditary disorders.
- Excess or deficiency of amniotic fluid.
- Polyhydramnios:
- Anencephaly.
- High intestinal obstruction.
- Maternal diabetes.
- Oligohydramnios:
- Renal disease.
- Persistent fetal malposition and presentation.
- Maternal ill-health in the first trimester e.g. rubella.
- Drugs taken in the first trimester e.g. alcohol, warfarin.
- History of recurrent fetal loss.
- Increased maternal age
How is ultrasound scanning utilized in definitive prenatal diagnosis?
Ultrasound scanning is useful in detecting a wide variety of abnormalities such as hydrocephalus, bowel atresias, renal tract and cardiac anomalies, etc.
What prenatal tests are conducted in the first trimester for trisomies?
The nuchal translucency or ‘triple test’ is performed in the first trimester for trisomies.
What role does radiological diagnosis play in definitive prenatal diagnosis?
Radiological diagnosis is used for conditions like bone diseases, e.g., osteogenesis imperfecta, and various forms of dwarfism.
Give an example of prenatal diagnosis through auscultation.
Fetal heart block can be diagnosed through auscultation.
How is prenatal sexing utilized in definitive prenatal diagnosis?.
Prenatal sexing is used for sex-linked abnormalities, e.g., haemophilia
What genetic tests are conducted on amniotic cells for prenatal diagnosis?
Fluorescence in situ hybridization (FISH) or chromosome analysis on amniotic cells, for example, is used for the prediction of trisomy 21.
What is the current emphasis in prenatal diagnosis?
The emphasis is placed on the screening and early diagnosis of fetal abnormalities between 12 and 20 weeks gestation.
The management of the situation and the family is of the utmost importance:
- Counsel, advise and support the family.
- Discuss and explain reason for abnormality. Confirm diagnosis if possible.
- Correct abnormality where possible, usually only after delivery.
- Consider termination e.g. anencephaly.
- Discuss future pregnancies.
- Close co-operation between the paediatrician, obstetrician, ultrasonologist,
geneticist and pathologist is essential (a ‘feta
