birth defects

Question 1

Birth defects definition

Answer 1

present at birth whether detected at that time or not

Some may be detectable at birth, before birth, in childhood, or in adulthood

Range of defects: structural, functional, behavioral, metabolic

2-3% at birth, 4-6/8% in early childhood (abortions not included)

Question 2

major and minor defects

Answer 2

major defects- more common in early embryo, most abort spontaneously (50-60% have chromosomal anomalies) have clinical and social consequence

minor defect- occur in 15% of newborns, a cue to look for major defects

Question 3

anomaly vs morphological variation

Answer 3

anomaly- a structural deformity of any kind (missing arm defects, disruptions, deformations, dysplasias)

morphological variation- predictable variation of the average morphological pattern, usually not significant, common (webbed toes)

Question 4

Defects (malformation)

Answer 4

A morphological abnormality resulting from abnormal developmental mechanism/processes

Defects are intrinsic or inherent to the developmental process, defects can be inherited

Question 5

Disruptions

Answer 5

A morphological abnormalities resulting from a breakdown or interference with an originally normal developmental process

Disruptions are extrinsic not inherent to the developmental process

disruptions cant be inherited

but can cause similar birth defects to defects

Question 6

Deformations

Answer 6

an abnormal form, shape or position of a normally formed body part

Deformations result from a non-disruptive mechanical forces that mold the fetus for long periods of time

Can sometime be reversible

Question 7

Dysplasia

Answer 7

Abnormal organization of cells- leads to organ failure

Question 8

Polytropic Field Defect

Answer 8

A pattern of anomilies derived from a disturbance of a single embryonic field

midline defect

Embryonic field- finite area of embryonic tissue developing into multiple and related structures

Question 9

Syndrome

Answer 9

a pattern of multiple primary anomilies which are seen together and are causally related (alcohol)

Question 10

Sequence

Answer 10

A pattern of anomilies which result from a single cause (like bad placenta)

Question 11

Association

Answer 11

A nonrandom occurence of 2 or more anomilies that occur more frequently together

Question 12

Causes of birth defects

Answer 12

Genetic factors (10-15%)
Environmental agents (7-10%)- infectious agents radiation drugs metals etc

most are unknown

Question 13

Suceptibility to a teratogenic agent

Answer 13

depends on time and genetics and dose and duration

Most susceptible- 3-8 weeks

week 1-3 abortion
Week 8+- usually functional and growth issues

most are multifactorial genetics and environment (20%) (60%)