NEPHRITIS IN PREGNANCY
In pregnancy the kidneys always give evidence of a constant
congestion, and the chief symptom of this is the great quantity
of renal epithelium shed with the urine. This engorgement has
given rise to the term "kidney of pregnancy." There has been much
discussion of this condition, especially as to the possibility of
differentiating it from beginning nephritis. In 227 consecutive cases
of pregnancy in which the urine was examined at short intervals by
myself throughout the entire gestation, there was always an enormous
quantity of epithelium, and this presence of epithelium is so
constant that its absence is a proof that pregnancy does not exist.
It is as physiological as any other somatic change in the puerperium.
Von Leyden and other German observers look upon the degenerative
alteration in the epithelium of the renal tubules as pathological,
but apparently more definite symptoms are necessary to make a
diagnosis of significant nephritis.
Williams[118] says that in the examination of 1000 pregnant women
at Johns Hopkins Hospital in Baltimore traces of albumin were found
in 50 per cent. without subsequent serious disturbance, but where
considerable albumin with casts other than hyaline was seen there
were symptoms of toxemia later, and several of these went on into
eclampsia. Fisher[119] held that red blood-corpuscles in these cases
indicate acute nephritis; and granular and epithelial casts, chronic
nephritis. Like the Johns Hopkins cases, he found albumin in 50 per
cent. of his patients. Albumin in slight quantities is found to be
extremely common toward the end of pregnancy. Meyer,[120] in an
extensive study of the kidney in pregnancy, made at Copenhagen,
found albumin in 5.4 per cent. of the women. During the last month of
gestation 71 per cent. of the women showed albumin. Premature births
occurred in 8 per cent. of the patients who had had albuminuria, but
in 21.5 per cent. of the women who had had casts. Delicate tests
for albumin are used by men who find these high averages, as a few
leucocytes from leucorrhoea will give the reaction. Most of these
cases have no clinical significance.
[118] _Obstetrics_, p. 456.
[119] _Praeger medizinische Wochenschrift_, 1892 n. 17.
[120] _Zeitschrift für Geburtshülfe_, bd. 16, n. 2.
It is usually impossible to differentiate in pregnancy a lighting
up of an old nephritis from a toxemia. Where there is a history of
nephritis before the pregnancy, this often clears up the diagnosis.
Nephritis is likely to manifest itself in pregnancy earlier than
toxemia; albuminuric retinitis is commoner in nephritis, but these
facts are no real help in differentiation.
The position of the uterus may be a cause of nephritis, according to
the _American Text-Book of Obstetrics_; but De Lee and others hold
that the growing womb cannot possibly be a cause. Many other origins
have been suggested, but without sufficient proof.
The treatment of the nephritides of pregnancy is that described in
chap. xiii for eclamptic symptoms. When albuminuric retinitis occurs,
the medical tendency is to empty the uterus. All text-books counsel
this procedure, but they give no convincing reasons for the advice.
If the child is viable the therapeutic abortion might be done when
necessary; if the child is not viable the operation is, of course,
not licit. In the nephritis of pregnancy it is not certain that
emptying the uterus artificially, with the entailed shock, is the
best method of treatment; but, as a rule, nephritis is made worse
by pregnancy, and the irritation lessens with the termination of
gestation in some cases, but not in true chronic nephritis. Eclampsia
is more toxic than nephritis, and the treatment may differ in
important details: it certainly is doubtful that artificial abortion
in eclampsia is the method of choice at present. I saw a case of
albuminuric retinitis ten years ago, which could not have been worse.
The woman was in the seventh month of gestation; she was nearly
blind and half comatose. The albumin in her urine _always_ was so
great that it would not fully precipitate in a centrifuge tube, and
every field under the microscope was covered with large casts in
such enormous quantities that they were felted together. Yet the
woman was carried on to term by Dr. Joseph O'Malley and delivered
of a fully developed child. She since has had two other children at
term who are perfectly healthy, and she herself could pass a life
insurance examination. This is, of course, only one case, and it is
exceptional; but it is impossible to say what will happen in any
particular case--whether it will go on to death or recovery.
Both subacute and chronic parenchymatous nephritis show clinically
much albumin, many casts, marked edema (except in very emaciated
cases), absence of high blood-pressure, and the heart is not
enlarged. This condition is caused commonly by chronic tuberculosis,
syphilis, sepsis, and malignant tumors. With these clinical symptoms
and the history, we may differentiate the nephritis of pregnancy
from Bright's disease. Again, acute intestinal nephritis or
glomerulonephritis has urinary findings like the nephritides just
described, and there may be edema. The heart and the blood-vessels
are normal. The cause is usually a pus microörganism, and there
may be anemia from the sepsis. In subacute glomerulonephritis, or
intestinal nephritis, the urinary findings are marked (much albumin
and many casts), anemia is rather constant, the blood-pressure
gradually goes up to 180 or 200, edema may be marked or absent. The
cause is usually a pus microörganism. Chronic glomerulonephritis
shows much epithelium and many casts (sometimes in showers), the
blood-pressure is high, the heart is usually somewhat enlarged,
there is polyuria and some blood, edema is common (but there are
dry cases), albuminuric retinitis is rare, and anemia is marked
and secondary. It may be difficult to find the cause of this
chronic glomerulonephritis, but there is, as a rule, a history of
tonsillitis, septic rheumatism, endocarditis, a true influenza, or
the like infection. Primary arteriosclerotic contracted kidney shows
hypertension and secondary circulatory disturbance. The urinary
findings are comparatively slight and transient, and there is little
or no anemia. The development is insidious, and the etiology is not
known.
There is evidence of late to find a septic cause for most of the
nephritides, such as infectious fevers, pyorrhea of the teeth,
and like bacterial intoxications; in pregnancy the nephritis may
be toxemic from sources that are not bacterial. It is extremely
difficult, and not seldom impossible, to make any differentiation, as
has been said. When the child is viable, whether the uterus should be
emptied or not must be decided for the individual case; no general
rule can be set down to cover all conditions.
One of the kidneys may be dislocated during pregnancy--usually the
right kidney. If a floating kidney becomes twisted on its pedicle,
abortion may be a consequence. The torsion may compress the renal
blood-vessels and bring on acute hydronephrosis with high fever,
great abdominal tenderness, and a peritonic facial expression.
Pyelitis of the renal pelvis is not seldom met in pregnancy. The
gonococcus, colon bacillus, or some other pyogenic bacterium gets a
nidus after pressure and lowered power of resistance. This condition
is sometimes mistaken for appendicitis.
Catalepsy is a rare complication of pregnancy, in which the woman
lies in an unconscious condition. The disease is a neurosis, but it
might be mistaken for a toxic or uremic condition by a superficial
observer. The infants of such women may be cataleptic, and may die as
a consequence of the condition.