Book of Medical Disorders in Pregnancy - Tintash

indicate an abnormal amount of protein
(I + or greater), a 4 hour urine.
Collection should be carried out. Ideally,
this 24 hour urine specimen should be a
clean voided specimen, and it should not
contain in excess of 200 mg. of protein
over 24-hours. Even in the event of
heavy vaginal discharge, urinary protein
content in excess of 500 mg. per 24-
hours is abnormal. Heavy proteinuria in
excess of 2 grams per 24 hours suggests
glomerular damage. In addition to chemical
studies of the urine, microscopic
examination of the urinary sediment is
an extremely important step. Normal
urinary sediment may contain one red
blood cell per high power field, or five
white blood cells; occasionally hyaline
casts may occur, approximately one in
15 high power fields in a spun drop of
urine. The content of white cells, red
cells and hyaline casts will be increased
in the presence of fever or following
exercise. It is obvious but important to
mention that if granular casts are
detected in the examination of the urinary
sediment, a high index of suspicion
for renal pathology should exist.
Bacteria should not be seen in a gram
stain of ordinary unsung specimen in a
high power field. If bacteria are present
in the specimen, in a high power field, it
is a rough indication that the colony
count of bacteria in the urine will be in
excess of 100,000 colonies per ml. of
urine. If bacteria are demonstrated on
Gram stain in a high power field of the
unsung specimen, a culture should be
carried out and colony counts and
sensitivity performed. Other laboratory
studies that assist in evaluation of renal
function include the BUN, creatinine, 24
hour creatinine clearance (which must be
corrected for pregnancy).
90
Radiological studies are usually unnecessary
in the pregnant patient, but
sometimes become mandatory. While
the principle of avoiding x-ray exposure
to the fetus in utero is a good one, in
certain cases (particularly of obstructive
uropathy) important information will be
missed if the IYP is not carried out. In
our unit we prefer to do a 'short IYP'.
The use of an image intensifier is
desirable if available to limit x-ray
exposure.
In the non pregnant state, renal biopsy is
often important to the complete elucidation
of complex renal problems. In pregnancy,
however, it is rarely necessary,
and should usually be deferred until after
the pregnancy has been completed. The
risk of significant hemorrhage from
renal biopsy during pregnancy is 1 %,
and it should be weighed against the
advantages of carrying out this procedure
at that time.
Abnormalities of the urinary tract in
pregnancy:
(a) Orthostatic albuminuria - In this
condition albuminuria (which is considered
significant) occurs when standing
or walking or following exercise. When
the 'patient is placed at rest, and in late
pregnancy at rest on her left side, the
albuminuria will disappear. The relationship
of orthostatic albuminuria to true
disease of the urinary tract is uncertain.
In cases where albuminuria is demonstrated,
with no other abnormal findings,
one may suspect the orthostatic nature of
the disorder. Follow up examination in
cases suspected of being orthostatic in
nature is extremely important to rule out
underlying diseases which may be missed
because of the limited investigation
possible in the pregnant patient.