How to determine the causes and recurrence risks of congenital anomalies - a clinical approach

Professor PA Farndon

This document amplifies the notes on fetal structural malformations in the Obstetrics Course Handbook. There is also a clinical picture quiz (in preparation) for you to test your clinical deductive skills!

A clinical approach

The pattern and nature of anomalies can often suggest the timing and cause of an embryological insult, and together with information from family and parental medical histories, may be helpful in determining whether the insult was environmental or genetic.

The clinical approach is to:

This approach is discussed on the following pages:

1    What is the anomaly and is it isolated or associated with other abnormal findings?

2     Do the nature and pattern of anomalies suggest the underlying cause?

3     What is the nature of the anomaly - malformation, deformation or disruption?

4     What is the pattern of anomalies - isolated anomaly, malformation syndrome/sequence, or association?

5     What additional information is available from family, pregnancy and personal medical histories?

6     Recurrence risks are related to the underlying cause

7    Environmental factors and teratogens

Summary - questions to ask

(in real life clinical practice or OSCEs!)

Is the anomaly an isolated single anomaly or are there others?

Did the anomalies occur during organogenesis or maturation?

Is the anomaly a malformation, deformation or disruption?

For multiple anomalies, consider two questions:

1. Can all the child's abnormalities be explained by a single anomaly or problem which has led to a cascade of subsequent structural defects? (ie a sequence)

2. Does the child have multiple structural defects which cannot be attributed to a single initiating abnormality and its consequences? (malformation syndrome or association)

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