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134

Melissa Scala

Chahira Kozma

25 Perimortem Sampling

A. Background

1. Perimortem sampling may help to establish the diagnosis in infants who die before diagnostic evaluation is

completed.

2. Approximately 25% of unexplained infant deaths in the

first week of life are due to undiagnosed congenital

anomalies. Infectious causes may account for a third of

unexplained deaths (1,2).

3. Inborn errors of metabolism are rare individually, but

in the general population the incidence may be >1 in

1,000 live births (3).

4. Diagnostic testing for congenital and metabolic disorders

can be time-consuming, so some infants may go undiagnosed and even die before the exact cause is elucidated.

5. Autopsy is declining worldwide. Neonatal autopsy rates

fell from 80% to 50% by the year 2000 (4).

6. Many parents today question the need for autopsy in an

era of sophisticated diagnostic testing. For some families, cultural or religious traditions may be barriers to

autopsy consent (5).

7. Even with autopsy, perimortem evaluation may be

essential, as some tests have low yield when performed

more than a few hours after death (6).

8. Neonatologists and pediatricians should be prepared to

independently obtain any necessary samples for diagnosis and to counsel the family regarding options for postmortem evaluation.

9. Information gathered during this period can be very

important for current and future generations (7).

10. If time allows, a genetics consult can be very useful in

guiding testing. If an inborn error of metabolism or

genetic disease is suspected, consultation before or

immediately after death is vital.

B. Indications (8,9)

1. Unknown cause of death

2. Suspected genetic disorder

3. Suspected inborn error of metabolism

4. Suspected undiagnosed infection

5. Suspected hypoxic-ischemic encephalopathy (10)

C. Discussion with the Family

1. Families of dying infants are under great strain, particularly if diagnosis is uncertain. An in-depth conversation

with the family can answer any questions they may have

and create a plan for perimortem sampling and for possible autopsy.

2. Informed consent may be obtained at this time for any

planned photographs or procedures.

D. Clinical Information

A detailed history and exam is important, particularly if a

geneticist has been unable to see the infant (3,11).

1. History

a. Maternal history: Ethnicity and medical history

b. Previous pregnancy history: Stillbirths or pregnancy

losses

c. History of this pregnancy, including

(1) Exposure to teratogens

(2) Amniotic fluid volume

(3) Results of amniocentesis and ultrasound

(4) Maternal illness

(5) Fetal movements

d. Family history including three-generation pedigree

(Table 25.1) (11).

e. Infant history: Report medical course for this

infant including diagnoses, treatments, and lab

results

2. Physical exam

a. Should be detailed and performed by specialist in

genetic metabolic disorders if possible

b. Important components include

(1) Growth parameters

(2) Hair pattern

(3) Facial features including eye and ear placement

(4) Abnormalities of hands and feet

(5) Genital and rectal exam

(6) Neurologic findings

(7) Skin abnormalities