Congenital defects and their scientific basis Flashcards
Congenital =
Present at birth
What % of liveborn infants are affected by congenital defects?
3%
Malformation =
Primary disturbance in embryogenesis
Disruption =
Secondary disturbance due to early influence of external factors
Deformation =
Late changes in a previously normal structure. Due to prolonged mechanical distress.
Causes of neonatal death:
- Preterm birth complications
- Intrapartum complications (e.g. asphyxia)
- Sepsis
- Congenital abnormalities
Congenital defects occur most commonly in
Low/middle income countries
What does CD being common in low/middle income countries mean?
May be preventable (e.g. food shortages, endemics)
Single gene defects and chromosomal defects are examples of what kind of abnormalities?
Primary/malformation
Teratogens cause what kind of abnormalities?
Secondary/disruptions
Ex of teratogens:
- Congenital infections
- Drugs and enviornmental pollutants
- Maternal metabolic disease
- Radiaition exposure
TORCH infections
Toxoplasmosis Rubella Cytomegalovirus Herpes Syphillis
Maternal metabolic diseases in pregnancy:
Diabetes, thyroid problems
Malformations at 2-4 weeks may cause
Polytrophic field defects
What is a polytrophic field defect?
Occurs early in trilaminar disc, can lead to scattered pattern of abnormalities
Ex of polytrophic field defects:
Di George
VACTERL (3+ of these)
DiGeorge =
Affects heart and thymus
VACTERL
Vertebral abnormalities Anal atresia Cardiac abnormalities Trachea-esophageal distula Renal anomalies Limb anomalies
Malformations at weeks 4-8
Monotrophic field defects
Ex of monotrophic field defects =
Cleft lip/palate
Ex of monotrophic field defect >9 weeks
Organ: spina bifida, cardiac
Ex of disruption:
Amniotic bands
Poland anomaly
Poland anomaly can be caused by …
Maternal cocaine use
Poland anomaly =
Interruption of subclavian artery vascular supply. Development of pectoral muscles effected.
