Obstetrical Hemorrhage

General Considerations
Mortality from Hemorrhage.
Obstetrics is “bloody business”. Even though the
maternal mortality rate has been reduced dramatically
by hospitalization for delivery and the availability of
blood for transfusion, death from hemorrhage remains
prominent in the majority of mortality reports. 11 %
of direct maternal deaths were caused by hemorrhage.
Maternal deaths from obstetrical hemorrhage decrease
tenfold from last 20 years.
Obstetrical hemorrhage is most likely to be fatal
to the mother in circumstances in which whole
blood or blood components are not available
immediately. The establishment and maintenance
of facilities that allow prompt administration of
blood are absolute requirements for acceptable
obstetrical care. For pregnancies complicated by
bleeding during the second and third trimesters
the rates of preterm delivery and prenatal
mortality are at least quadrupled.
 Blood loss at parturition.
Loss of more 500 mL of blood after
completion of the third stage of labor has
persisted as the definition of postpartum
hemorrhage.
Nonetheless nearly one half of all women
who are deliverer vaginally , and almost all
who undergo cesarean delivery , shed that
amount of blood or more, when measured
quantitatively .
The woman with normal pregnancy-induced
hypervolemia usually increases her blood volume by 30
to 60 %, which for an average -sized woman amounts to
1 to 2 L. Consequently , she will tolerate , without any
remarkable decrease in postpartum hematorcit, blood
loss at delivery that approaches the volume of blood she
added during pregnancy.
Conditions that predispose to obstetrical
hemorrhage.

The serious hemorrhage may occur at any time

throughout pregnancy and the puerperium. The time of
bleeding in pregnancy is widely used to classify
obstetrical hemorrhage ; however the term third-
trimester bleeding is so iomprecise for describing
gestational age and in turn, intelligent management of
pregnancy , that it ought to be abandoned .
The bleeding may be the consequence
of
-separation of a placenta implanted in
the immediate vicinity of the cervical
canal- that is - placenta previa;
-from separation of a placenta located
elsewhere in the uterine cavity- that is -
abruption placentae.
Rarely, the bleeding may be the
consequence of velamentous insertion
of the umbilical cord with rupture of
a fetal blood vessel at the time of
rupture of the membranes -vasa previa -
with fetal hemorrhage.
 The source of uterine bleeding , that
originated above the level of the cervix is
not always identified . In that circumstance,
the bleeding typically beings with little or
no other symptomatology and then stops
and at delivery no anatomical cause is
identified. Almost always the bleeding must
have been the consequence of slight
marginal separation of the placenta that did
not expand.
It is emphasized that the pregnancy in
which such bleeding occurs remains at
increased risk for a poor outcome
even though the bleeding soon stops
and placenta previa appears to have
been excluded by sonography.
Etiology of obstetrical hemorrhage .
Obstetrical hemorrhage is the
consequence of excessive bleeding
from the placental implantation site,
trauma to the genital tract and adjacent
structures , or both.
Uterine atony and genital tract
lacerations therefore account for most
cases of postpartum obstetrical
hemorrhage.
 Bleeding from placental site.
Near term, it is estimated that approximately 600
mL/min of blood flows through the intervillous
space . With separation of the placenta, the many
uterine arteries and veins that carry blood to and
from the placenta are severed abruptly.
Elsewhere in the body, hemostatis in the absence
of surgical ligation depends upon intrinsic
vasospasm and formation of blood clot locally.
 At the placental implantation site most
important for achieving hemostasis are
contraction and refraction of the myometrium
and thereby impair hemostatsis at the
implantation site. Fatal postpartum hemorrhage
can occur from a hypotonic uterus while the
maternal blood coagulation mechanism is
adjacent to the denuded implantation site
contracts and retracts vigorously.
Bleeding from lacerations .
Lacerated or incised blood vessels in the
reproductive tract, other than those in the body
of the uterus , lack the unique mechanism for
obliterating vessel patency provided by a
vigorously contracting myometrium. Therefore ,
following delivery of an intact placenta,
hemorrhage from the genital tract that persists
with the uterus firmly contracted is almost
certainly indicative of bleeding from lacerations.
Management of hemorrhage
Whenever there is any suggestion of excessive blood
loss from the genital tract, it is essential that steps be
immediately taken to identify the presence of uterine
atony, retained placental fragments, and lacerations of the
genital tract. It is imperative that at least one -in the
presence of frank hemorrhage , two- intravenous
infusion systems of large caliber be established
immediately to allow rapid administration of electrolyte
solutions and blood. An operating room, surgical team,
and an anesthesiologist should always be immediately
available .
 Estimation of excessive blood loss.
Visual Estimate . Visual inspection is most
often resorted to but is notoriously inaccurate.
In several reports, the amount of blood
estimated by inspection to behave been lost
was on average about one half the actual
measured loss. We have found that if estimated
blood loss is “excessive” (more than average),
final calculations usually show an actual loss of
about three times the estimate!
 Blood pressure and pulse.
Overt hypotension and tachycardia are signs of dangerous
hypovolemia that cannot be ignored , but the converse is not
necessarily true. Vital signs, if apparently normal, can be quite
misleading. A blood pressure reading in the normal
range, or even hypertension, does not preclude
imminently dangerous hypovolemia. The pulse rate may be
equally misleading because it may be elevated in circumstances
in which the degree of hemorrhage is negligible, and normal
or even slow in the presence of severe hypovolemia.
 Urine Flow.
When carefully measured, the rate of urine
formation, in the absence of potent
diuretics , reflects
the adequacy of renal perfusion and , in
turn, the perfusion of other vital organs,
because renal blood flow is especially
sensitive to blood volume changes.
 Actually, the reverse is more likely true, in that there is great
potential for deleterious effects . An almost immediate effect
of furosemide is venodilatation, which further reduces venous
return to the heart, thereby further compromising cardiac
output.
The other dangerous effect is loss of fluid and electrolytes
from the already seriously depleted intravascular
compartment . The antidiureitc agent to which the
hemorrhaging woman is likely to be exposed is oxytocine.
However, with the infusion of isotonic electrolyte solution,
such as lactated Ringer solution , the amount of free water that
is reabsorbed by the renal tubules is not gently enhanced, and
therefore severe oliguria does not develop as the consequence
of oxytocin alone.
With potentially serious hemorrhage
an indwelling catheter should be
inserted promptly to measure all urine
formed. Potent diuretics, such as
furosemide, are very likely to invalidate
the relationship between urine flow
and renal perfusion.
 Fluid and blood replacement.
Treatment of serious hemorrhage demands prompt and
adequate refilling of the intravascular compartment. Two
general guidelines have proven to be most valuable for
determining the amounts and kinds of fluids that are
needed to treat hypovolemia from obstetrical
hemorrhage irrespective of case.
Lactated Ringer solution and blood are given in
such amounts and in such proportions that (1)
urine flow is at least 30 mL/hr and ideally
approaches 60mL/hr, and (2) the hematocrit is
maintained at 30 %.
 For the woman who is isovolemic,
physiologically stable, and in whom
hemorrhage has abated and none
further is expected , treatment of
residual acute anemia differs from
management of acute hemorrhage.
 Blood and component replacement
Compatible whole blood would appear to be
ideal for treatment of hypovolemia from serious
acute hemorrhage . The policy of the Obstetrics
Service dictated by the practicalities of blood
banking, is to treat hypovolemia from severe
hemorrhage with any readily availbae whole
blood that is compatible based on identification
of the recipient’s blood group and the absence of
abnormal red cell antibodies in the recipient’s
plasma.
Packed red cells plus recently thawed
fresh-frozen plasma are administered
when serious hemorrhage encountered
 PLACENTAL ABRUPTION
Nomenclature .
The separation of the placenta from its site of
implantation before the delivery of the fetus has
been variously called placental abruption ,
abruption placentae, accidental hemorrhage and
premature separation of the normally implanted
placenta .
The term premature separation of the normally
implanted placenta is most descriptive , because
is differentiates the placenta that separates
prematurely but is implanted some distance
beyond the cervical internal os, from one that is
implanted over the cervical internal os- that is ,
placenta previa. The Latin abruption placentae
which means “rending asunder of the placenta” ,
denotes a sudden accident a clinical characteristic
of most cases of this complication.
Some of the bleeding of placental abruption usually
insinuates itself between the membranes and uterus, and
then escapes through the cervix, causing and external
hemorrhage. Less often , the blood does not escape
externally but is retained between the detached placenta
and the uterus , leading to concealed hemorrhage.
Placental abruption may be total , or partial . Placental
abruption with concealed hemorrhage carries with it
much greater maternal hazards, not only because the
likelihood of intense consumptive coagulopathy is
increased, but also because the extent of the
hemorrhage is not appreciated .
 Frequency , intensity and significance .
The frequency with which abruptio placentae is
diagnosed will vary, because criteria employed
for diagnosis differ. The intensity of the
abruption will often vary depending on how
quickly the woman seeks and receives care
following the onset of symptoms. With extensive
separation causing death of the fetus is increased
remarkably. The reported frequency for placental
abrutpio varies but averages about 1 in 150
deliveries .
.
Etiology.
The primary cause of placental abruption is
unknown, but there are several associated
conditions. The incidence increases with age , the
scientists have shown it to be higher in women of
great parity and it is more common in African -
American women than white or Latin-American
women .
The most commonly associated condition is
either Pregnancy-induced or chronic
hypertension.
Preterm prematurely ruptured membranes have
been associated with an increased incidence of
premature placental separation.
External trauma could be implicated only in 3 of 207
cases of severe placental abruption . A case of marginal
abruption caused by percutaneous umbilical cord blood
sampling was described by some scientists too.
Cigarette smoking was linked to an increased risk for
abruption. Smoking causes about 40 % of cases of
placental abruption .
Cocaine abuse has been associated with an
alarming frequency of placental abruption . The
onset of labor with placental abruption in 4 of
23 women immediately after intravenous self-
injection of cocaine. In another report of 50
women who abused cocaine during pregnancy,
there were 8 stillbirths caused by placental
abruption.
Uterine leiomyoma, especially if located behind
the placental implantation site, predispose to
abruption .
 Recurrence.
The risk of recurrent abruption in a subsequent
pregnancy is very high. Management of the
subsequent pregnancy is made difficult by the
fact that the placental separation may suddenly
occur at any time, even remote from term. In the
majority of cases, fetal well-being was normal
beforehand, and thus currently available methods
of fetal evaluation are usually not predictive.
 Pathology.
Placental abruption is initiated by hemorrhage
into the deciduas basalis. The deciduas the splits,
leaving a thin layer adherent to the myometrium.
Consequently, the process in its earliest stages
consists of the development of a decidual
hematoma that leads to separation , compression
and the ultimate destruction of the placenta
adjacent to it .
 Clinical Diagnosis
It is emphasized that the signs and symptoms
with abruption placentae can vary considerably.
For example , external bleeding can be profuse,
yet placental separation may not be so extensive
as to compromise the fetus directly; or there may
be no external bleeding but the placenta may be
completely sheared off and the fetus dead as the
direct consequence.
In 22 % of cases idiopathic preterm labor was
considered to be the diagnosis until subsequent
fetal distress - including fetal death , serious
bleeding, back pain, uterine tenderness , rapid
uterine contractions or persistent uterine
hypertonus- were detected singly or more often
in combination. Importantly , negative
findings with ultrasound examination do not
exclude life-threatening placental abruption.
Differential diagnosis. In severe cases of placental
abruption, the diagnosis is generally obvious. Milder
and more common forms of abruption are difficult to
recognize with certainty, and the diagnosis is often
made by exclusion. Therefore, with vaginal bleeding
complicating a viable pregnancy, it often becomes
necessary to rule out placenta previa and other causes
of bleeding by clinical inspection and ultrasound
evaluation. Painful uterine bleeding means abruption
placentae , while painless uterine bleeding is indicative of
placenta previa. Unfortunately , the differential
diagnosis is not that simple
Early-onset placental abruption. Classical
placental abruption with pain, shock , uterine
rigidity and absent fetal heart sounds may
develop in the middle trimester. From our
experiences, these women may present the same
complications as do those with more advanced
pregnancies ; thus, abruption may cause maternal
death unless appropriate treatment is given.
 Consumptive Coagulopathy.
One of the most common cause of clinically significant
consumptive coagulopathy in obstetrics is placental
abruption . Overt hypofibrinogenemia -less than 150
mg/dl of plasma, along with elevated levels of
fibrinogen- fibrin degradation products and variable
decreases in other coagulation factors - is found in about
30 % of women with placental abruption severe enough
to kill the fetus. Such coagulation defects are much less
common in those cases in which the fetus survives.
Renal Failure. Acute renal failure that persists for any length
of time is rare with lesser degrees of placental abruption but is
seen in sever forms when there is delayed or incomplete treatment
of hypovolemia. The precise cause of renal damage that may be
associated with placental abruption is not clear, but major factors
very likely are seriously impaired renal perfusion from both
reduced cardiac output and intra-renal vasospasm as the
consequence of massive hemorrhage and, at times , coexisting
acute or chronic hypertensive disorders. Severe preeclampsia
frequently coexists with placental abruption . Even when placental
abruption is complicated by sever intravascular coagulation ,
prompt and vigorous treatment of hemorrhage with blood and
electrolyte solution will most often prevent clinically significant
renal dysfunction.
Uteroplacental Apoplexy (Couvelaire Uterus).
In the more sever forms of placental abruption ,
widespread extravasation of blood into the
uterine musculature and beneath the uterine
serosa is found. This phenomenon of
uteroplacental apoplexy that is frequently called
Couvelaire uterus . Such effusions of blood are
also occasionally seen beneath the tubal serosa ,
in the substance of the ovaries , as well as free in
the peritoneal cavity .
Management
Treatment for placental abruption will vary
depending upon the status of the mother and
fetus. With the development of massive external
bleeding, intense therapy with blood plus
electrolyte solution, and prompt delivery to try
to control the hemorrhage , together are
lifesaving for the mother and hopefully, for the
fetus.
If the fetus is alive and there is no evidence
of fetal compromise (persistent bradycardia
decelerations, or a sinusoidal heart rate
pattern), and if maternal hemorrhage is
not causing serous hypovolemia or
anemia, procrastination with very close
observation, coupled with facilities for
immediate intervention, can be practiced .
( In cases when the fetus is immature)
Sonography has served in some cases to identify
a blood clot in the uterine cavity formed as the
consequence of placental abruption. As
emphasized earlier, failure to so identify such a
clot does not exclude serious placental abruption.
The placenta may further separate at nay instant
and seriously compromise or kill the fetus unless
delivery is performed immediately.
Cesarean Delivery . Rapid delivery of the fetus who is
alive but in distress practically always means c-section .
At first impression at least fetal bradycardia of 80 to 90
beats per minute, with a degree of beat-to-beat variability,
seemed evident. The fetus, however , was dead. there
were no audible fetal heart sounds and the maternal
pulse rate was identical to that recorded through the
fetal scalp electrode. C-section at this time would likely
have proved dangerous for the mother because she was
profoundly hypovolemic and she had severe
hypfobrinogenemia . If the fetus is alive but c-delivery is
not carried out promptly, the fetus must be monitored
for evidence of distress and be delivered immediately
whenever distress is detected.
Vaginal Delivery. If placental separation is so
severe that the fetus is dead, vaginal delivery is
preferred unless hemorrhage is so brisk that is
cannot be successfully managed even by
vigorous blood replacement or there are other
obstetrical complications that prevent vaginal
delivery. With vaginal delivery, stimulation of the
myometrium pharmacologically and by uterine
massage will cause vessels to be constricted so
that serious hemorrhage is voided even though
coagulation defects persist.
Labor. With slight degree of placental
separation , uterine contractions are usually of
normal frequency , duration, and intensity. With
extensive placental abruptions, the uterus will
likely be persistently hypertonic.
If sever placental abruption develops before
cervical effacement and dilation , the subsequent
pattern of change in the cervix is typically one of
progressive effacement with little dilation until
effacement is complete . Dilation is then usually
rapid.
Hemorrhage and hypovolemia
Basic rules for treating obstetrical hemorrhage are
applied . Blood and lactated Ringer solution
are infused in such proportions that the
hematocrit is maintained at 30 % or slightly
higher and urine flow is at least 30 mL/ hr.
For the oliguric patient , the dangers from
furosemide outweigh any advantages .
PLACENTA PREVIA
Definition
In placenta preiva , the placenta is located over or very near the
internal os. Four degrees of the abnormality have been recognized:
1. Total palcenta preiva. The internal cervical os is covered
completely by placenta
2. Partial placenta previa. The internal os is partially covered by
placenta
3. Marginal placenta previa . The edge of the placenta is at the
margin of the internal os.
4. Low -lying placenta. The placenta is implanted in the lower
uterine segment such that the placental edge actually does not
reach the internal os but is in close proximity to it .
The degree of placenta previa will depend in large
measure on the cervical dilatation oat the time of
examinations . For example, a low-lying placenta at 2 cm
dilatation may become a partial placenta previa at 8 cm
dilatation because the dilating cervix has uncovered
placenta. Conversely, a placenta previa that appears to
be total before cervical dilatation may become partial
at 4 cm dilatation because the cervix dilates beyond the
edge of the placenta. Digital palpation to try to
ascertain these changing relations between the
edge of the placenta and the internal os as the
cervix dilates can incite sever hemorrhage!
Frequency. The zygote that implants
very low in the uterine cavity likely is to
form a placenta that at the outset lies in
very close proximity to the internal
cervical os. The placenta so located
usually migrates toward the fundus, or
it may remain in situ, giving rise to
placenta previa.
Etiology
Multiparity and advancing age increase the risk of
placenta previa. Prior c-delivery or induce abortion
increases the likelihood of placenta previa. Defective
decidual vscularization , the possible result of
inflammatory or atrophic changes, has been implicated
in the development of placenta previa.
Placenta previa may be associated with placenta accrete
or one of its more advanced forms, placenta increta or
percreta. Such abnormally firm attachment of the
placenta might be anticipated because of poorly
developed deciduas in the lower uterine segment.
Clinical Findings
Signs and symptoms. The most
characteristic even in placenta previa is
painless hemorrhage , which usually does
not appear until near the end of the second
trimester or after. Many abortions, however
, probably result from such an abnormal
location of the developing placenta
Character of bleeding.
Frequently , bleeding from placenta previa
has its onset without warning in a woman
who had an uneventful prenatal course.
Occasionally, it makes its first appearance
while she is asleep, and on awakening , she
is surprised to find herself lying in blood .
Fortunately , the initial bleeding is rarely
so profuse as to prove fatal. Usually , but
certainly not always , it ceases spontaneously
, only to recur.
Diagnosis. In women with uterine bleeding
during the latter half of pregnancy, placenta
previa or abruptio placentae should always be
suspected. The possibility of placenta previa
should not be dismissed until appropriate
evaluation, including sonography, has clearly
proved its absence. The diagnosis of placenta
previa can seldom be established firmly by
clinical examination unless a finger is passed
through the cervix and the placenta is palpated.
Such examination of the cervix is never
permissible unless the woman is in an
operating room with all the preparations for
immediate c-section, because even the
gentlest examination of this sort can cause
torrential hemorrhage .
Localization by Sonography. The simplest, most precise
and safest method of placental localization is provided
by trans-abdominal sonogrpahy, which is used to locate
the placenta with considerable accuracy. Accuracies of
as high as 98 % have been obtained.
Magnetic resonsnce imaging. Preliminary investigation
using magnetic resonance imaging to visualize placental
abnormalities , including placenta previa have been
reported by several groups.
Management
Women with a placenta previa may be
considered as follows: (1) those in whom
the fetus is preterm but there is no pressing
need for delivery; (2) those in whom the
fetus is reasonably mature; (3) those in
labor; (4) those in whom hemorrhage is so
severe as to mandate delivery despite fetal
immaturity.
Delivery. C-section is the accepted method of delivery
in particularly all cases of placenta previa , primarily for
the welfare of the mother . When the placenta lies far
enough posteriorly that the lower uterine segment can
be incised transversely without encountering placenta,
bleeding, both maternal and fetal , could be sever and
extension of the incision to involve one or both
uterine arteries could occur with surprising ease.
Therefore , with anterior placenta previa, a vertical
uterine incision may be safer.
Hemorrhage with abortion
Etiology of hemorrhage . Remarkable blood loss ,
especially acute hemorrhage but sometimes chronic, may
occur as the consequence of abortion. Hemorrhage
during the first trimester is less likely to be severe
unless the abortion as induced and the procedure was
traumatic. However, when the pregnancy is more
advanced, the mechanisms responsible for the
hemorrhage are most often the same as those described
for placental abruption and placenta previa- that is , the
disruption of a large number of maternal blood vessels
at the site of placental implantation without myometrial
contraction appropriate for mechanical constriction of
these vessels.
Coagulation defects
Serious disruption of the coagulation
mechanism as the consequence of abortion
may develop in the following
circumstances: (1) prolonged retention of a
dead fetus ; (2) sepsis, a notorious cause; (3)
the intrauterine instillation of hypertonic
saline or urea solutions ; (4) medical
induction with a prostaglandin; (5) during
instrumental termination of the pregnancy .
THE END.