3. CONGENITAL
MALFORMATIONS- Definition
Morphological defects present at
birth. May sometimes manifest in later
adult life
Due to an intrinsically abnormal
developmental process
May either be inherited or acquired
3% of neonates have a major anomaly
Up to 20% of (post)neonatal deaths
5. 1 in 2000 live births
DISRUPTION- Amniotic band
2 THEORIES
1. Partial rupture of
amniotic sac forms
amniotic strands that
encircle and trap part of the
foetus
2. Intrinsic defect of blood
circulation
Characterised by
constriction of digits, arms
and legs
Accompanied by
lymphoedema
Auto amputation may occur
6. CONGENITAL MALFORMATIONSDifferential diagnosis- 2
DEFORMATION- Localised/generalised
compression of foetus by extrinsic
forces
such as 1st pregnancy, small uterus,
bicornuate uterus, leiomyoma,
oligohydramnios, multiple pregnancy,
abnormal presentation
e.g. talipes
8. DEFORMATIONTalipes equinovarus
Club foot may be
classified as
1. structural (hereditarye.g. Edward’s syndrome,
Ehlers-Danlos syndrome)
2. Postural (intrauterine
compression)
Against the classical,
widely accepted teaching
of postural club foot, this
anomaly also occurs in
the absence of restriction
of the intrauterine space
12. PLACENTA IN
OLIGOHYDRAMNIOSAmnion nodosum
a localized
accumulation of
amorphous
material (vernix
caseosa) with
embedded
desquamated
foetal skin cells to
produce small
nodules
13. CONGENITAL MALFORMATIONSTerminology
SYNDROMEConstellation of congenital
anomalies that are pathologically
related and not due to a single
localised initiating defect. May be
caused by single agent (virus,
alcohol, etc.)- e.g. Congenital
Rubella syndrome
15. ASSOCIATION
A group of anomalies that occur more frequently
together than would be expected by chance alone
but that do not have a predictable pattern of
recognition and/or a suspected unified
underlying aetiology.
Examples include
• VACTERL (Vertebral, Anal, Cardiac, TE fistula,
Renal, Limb defects) and
• MURCS (Mullerian duct aplasia, Renal aplasia,
Cervical Somite dysplasia
22. Risk factors for major malformations
Queiβer-Luft and Spranger, 2006
23. MULTIFACTORIAL CAUSES
20-25% of malformations
Interaction between several disease
genes and multiple environmental
factors
Subject to geographic and temporal
variation
Congenital dislocation of the hip, neural
tube defects
56. Summary
• An overview of processes that can result in
acquired or inherited structural malformations
manifesting at the time of birth or in some cases
later in life has been presented
• Malformations arise from insults occurring
during the critical period of organogenesis and
may range from minor to severe, life threatening
conditions
• Many cases are preventable by the avoidance of
teratogenic exposure, immunisation and genetic
56
counselling in selected cases