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Placenta Increta in a Young Primigravid as a
Cause of Uterine Rupture
Maja Kristina J. Ruiz, MD 1, Debbie-Lyn C. Uy, MD, FPOGS, FPSUOG 1
A B
Uterine rupture and placental accreta spectrum are two rare occurrences in
pregnancy that could threaten the lives of both the mother and the unborn fetus.
The incidence of uterine rupture in an unscarred uterus is 0.7 per 10,000
pregnancies. Similarly, the incidence of placenta accreta spectrum is only 0.12
to 0.31 percent. Majority of cases of morbidly adherent placenta and uterine
rupture occur in patients who have a history of uterine surgery or trauma.
Placenta accreta spectrum is an unusual cause of uterine rupture and obstetric
hemorrhage especially when there is no previous trauma to the uterus.
This report is an extraordinary case of acute abdomen in a young primigravid in
the second trimester of pregnancy. Urgent ultrasound of the lower abdomen
showed findings consistent uterine rupture, moderate hemoperitoneum and
intrauterine fetal demise necessitating emergency laparotomy and
peripartum hysterectomy. Histopathologic examination confirmed the presence
of placenta increta.
The occurrence of an abnormally adherent placenta can have catastrophic
sequelae. Management is varied and largely depends on the degree of
involvement of the myometrium and surrounding structures. Treatment often
involves hysterectomy but in cases where fertility preservation is desired,
conservative management may be attempted in an effort to avoid maternal
morbidity and mortality associated with the condition while maintaining the
patient’s childbearing capacity. Successful management of such cases depends
mainly on early detection and timely intervention.
Keywords
Placenta Accreta Spectrum, Placenta Increta, Unscarred Uterus, Uterine
Rupture
ABSTRACT
CASE REPORT
1 Department of Obstetrics and Gynecology, Corazon Locsin Mon-telibano Memorial Regional Hos-pital Correspondence Maja Kristina J. Ruiz, MD [email protected] Recceived February 15, 2021 Accepted June 7, 2021 Cite as Ruiz MKJ, Uy DLC, Placenta In-creta in a Young Primigravid as a Cause of Uterine Rupture, Cor Illumina 2021; 1:38-43, https://clmmrhresearch.com/corillumina/ruiz2021.pdf Copyright © Ruiz MKJ et al 2021
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INTRODUCTION
Uterine rupture is a rare occurrence that
could threaten the lives of the pregnant mother and
the fetus. It is especially rare in an unscarred uterus
with an overall incidence of 0.7 per 10,000 deliver-
ies (1). Another unusual occurrence in pregnancy is
the placenta accreta spectrum, formerly known as
morbidly adherent placenta, which could be classi-
fied as either placenta percreta, placenta increta or
placenta accreta depending on the depth of inva-
sion. These placental invasion anomalies result in
adherence of the placenta to the uterine wall which
leads to failure of placental detachment after deliv-
ery (2). Majority of cases of morbidly adherent pla-
centa and uterine rupture occur in patients who
have a history of uterine surgery or trauma which
include a previous cesarean delivery, myomectomy
or repeated curettage, and could lead to a life-
threatening condition for both mother and fetus
due to severe bleeding. In the last 30 years, the in-
cidence rose from 0.12 to 0.31 percent (3). Placenta
accreta spectrum has become a serious obstetrical
issue over the years.
In the Philippines, there is only one published
case of placenta accreta in an unscarred uterus.
The patient, however, was not a primigravida (4).
In our institution, out of a total of 22, 209 deliver-
ies over the last five years, there have only been two
reported cases of placenta accreta or its spectrum
that occurred in an unscarred uterus, representing
only 0.014 percent. The first was a case of placenta
accreta in a postpartum multigravida with retained
placenta, and the other is placenta increta in a nul-
lipara with extrauterine pregnancy. The presence
of a morbidly adherent placenta
in an unscarred uterus and dur-
ing the first pregnancy is an ex-
ceptional case.
This report is an unusual
case of uterine rupture occurring
in a young primigravid that
showed a morbidly adherent pla-
centa with a histologic finding of
a placenta increta at 24 weeks of
gestation.
CASE PRESENTATION
This is a case of an 18-year-
old primigravid who was rushed
to the Emergency Room with a
chief complaint of severe ab-
dominal pain that started ten
hours prior. She had an amenorrhea of 24 5/7
weeks and had two prenatal consultations at a local
health center with unremarkable findings. Upon
arrival at the ER, the patient was in severe ab-
dominal pain. She was hypotensive, tachycardic
and tachypneic, but was afebrile. On physical ex-
amination, she was noted to have pale conjunctiva
and anicteric sclera. Examination of the abdomen
revealed a gravid uterus with a fundic height of
22cm but fetal heart tones were not appreciated.
There was direct tenderness and muscle guarding.
Pelvic examination revealed a closed cervix with a
uterine size that is compatible with age of gestation.
Uterine contractions and vaginal bleeding were not
present, indicating that the patient was not in pre-
term labor. The initial impression on admission
was acute abdomen probably secondary to Rup-
tured Appendicitis. Ultrasound of the lower abdo-
men was immediately performed and it showed
that the myometrium at the fundal region meas-
ured only 0.2cm. There was a collection of medium
level echo fluid in the abdominopelvic cavity along
with the absence of fetal cardiac activity. So-
nographic findings were consistent with uterine
rupture, moderate hemoperitoneum and intrauter-
ine fetal demise. The patient was immediately
scheduled for emergency laparotomy.
Intraoperatively, approximately 300mL of
blood clots admixed with blood were evacuated.
The omentum was adherent to the anterior surface
of the uterus (Figure 1). Further exploration re-
vealed a uterus consistent in size with a 24-week
gestation. There was a violaceous, well circum-
scribed mass on the fundal portion along with an
Figure 1. (a) Initial laparotomy findings. Encircled is the omentum that is adherent to the uterus. (b) Blood clots evacuated from the abdominal cavity
(yellow arrow), volume approximately 300ml.
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Cor Illumina, Volume 1, Issue 1, September 2021
area of disruption on the myometrium that extend-
ed up to the serosa (Figure 2). The impression at
this time was placenta percreta because of evidence
of trophoblastic invasion up to the level of the sero-
sa. Peripartum hysterectomy was performed be-
cause severe hemorrhage with any attempt to re-
move the placenta was anticipated. The rest of the
pelvic organs were grossly normal. The abdomen
was closed in layers using the standard technique.
On gross examination of the specimen, the
myometrium at the fundal area of the gravid uterus
was interrupted by placental tissue invading
through it and the serosa. Cut section of the uterus
revealed an intrauterine stillborn, preterm, female
fetus weighing 750 grams, with a crown-heel length
of 31 centimeters. The placenta was adherent to the
anterofundal wall of the uterus (Figure 3). Anemia
and hypovolemia were managed with blood prod-
ucts. Patient’s vital signs were stable postopera-
tively and she was discharged on the 4th hospital
day.
Histopathologic examination of the specimen
was consistent with placenta increta of the uterus
and mature third trimester placenta with infarct as
shown in Figure 4.
DISCUSSION
Placental development starts during implan-
tation, when the embryo attaches to the endometri-
al surface of the uterus and invades the epithelium
and the maternal circulation. This interaction hap-
pens between the activated blastocyst and the uter-
us. The placenta, which is shown in the next figure,
is composed of the fetal side and the maternal side,
namely, the chorionic plate and the basal plate re-
spectively. Between the chorionic plate and the ba-
sal plate is the intervillous space. In the third tri-
mester of pregnancy, there is the development of
the Nitabuch’s layer. It is at this layer where pla-
centa detachment from the uterus occurs during
delivery (5).
Implantation happens in a highly organized
process that consists of “apposition”, “adhesion”
and “invasion”. Apposition is the initial contact be-
tween the blastocyst and the uterine endometrium
which usually occurs on the upper part of the uter-
us or the fundus where the endometrial tissue
blood flow is highest, making it a favorable site for
implantation. Adhesion makes this contact even
stronger. During these two processes, the blastocyst
differentiates into the embryo or the inner cell
mass, and the placenta or the trophoblast. Any
dysfunction in these processes would result in ab-
normal placentation that can affect both the mother
and the fetus. Further differentiation of the troph-
oblast cells of the blastocyst results in the for-
mation of villous and extravillous trophoblasts. In
addition, the endometrial stroma is also trans-
formed into a specialized secretory endometrium
called the decidua. This decidualized endometrium
is the site of blastocyst implantation. The extravil-
lous trophoblasts then become the endovascular
A
B
Figure 2. The gravid uterus. (a) Intraoperative picture of the uterus showing a violaceous, well circumscribed mass
on the fundal portion with a point of rupture that en-croaches in the myometrium and into the serosa. (b)
Gross picture revealing the extent of invasion of the mass through the serosa.
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Cor Illumina, Volume 1, Issue 1, September 2021
Figure 3. Uterine specimen. (a) The uncut uterus showing a morbidly adherent placenta. (b) The uterus cut with a stillborn fetus attached
into the uterus through the umbilical cord. The endomyometrial junc-tion at the fundal area of the uterus is unrecognizable because of the
adherent uterus.
A B
trophoblasts or interstitial trophoblasts that would
either invade the maternal blood vessels or aid in
vascular remodeling by migrating through the de-
cidua and the myometrium, respectively. Attach-
ment of the chorionic villi directly in the myometri-
um because of the absence of decidua over the lat-
ter results in abnormally invasive placentae (5).
In the placenta accreta spectrum, there is an
abnormal placental adherence to the myometrium
from either partial or total absence of the decidua
basalis and faulty development of the Nitabuch lay-
er. The three classifications as shown in the figure
below are differentiated by the depth of the tropho-
blastic growth. In placenta accreta, the villi are at-
tached to or in direct contact with the myometrium.
In placenta increta, the villi invade into or through
the myometrium. Placenta percreta, on the other
hand, is the type of implantation wherein the villi
penetrate beyond the myometrium and the serosa
into surrounding structures.
The diagnosis of Placenta accreta spectrum
is based on the histopathologic examination char-
acterized by the absence of the decidua along with
identification of chorionic villi adjacent to the my-
ometrial fibers (6). This histopathologic picture is
seen in the case presented. As seen in the micro-
scopic pictures in Figure 4, the chorionic villi have
already invaded into the myometrium consistent
with a histopathologic diagnosis of placenta incre-
ta.
Risk factors known for the placenta accreta
spectrum include a previous cesarean delivery, ad-
vanced maternal age, multiparity, prior uterine sur-
geries or curettage and Asherman syndrome (7).
None of these risk factors are present in our case as
the patient is a young primigravida with no history
of prior uterine surgery.
A popular hypothesis explaining the develop-
ment of placenta accreta spectrum states that a de-
fect of the endometrial-myometrial interface in the
area of the uterine scar leads to the failure of nor-
mal decidualization, thereby, allowing development
of abnormally deep placental anchoring villi and
trophoblast infiltration. Disruptions in the uterine
cavity cause damage to the endometrial-
myometrial interface, thereby affecting the devel-
opment of scar tissue and increasing likelihood of
placenta accreta (7). We cannot, however, attribute
this pathophysiology to this case because placenta
increta occurred in a nulliparous woman without
any history of uterine surgery or instrumentation
making this case unusual.
Uterine rupture can be potentially lethal for
both mother and the fetus. Its prevalence is as low
as 1% in women who had previous cesarean section,
and 0.7 in 10,000 pregnant women without prior
gynecological surgery or history of cesarean sec-
tion. The reported risk factors in an unscarred
uterus include macrosomia, shorter interval be-
tween deliveries, post-date pregnancies and ad-
vanced maternal age (8). Interestingly, this case
had neither of the factors mentioned. Our patient is
a young primigravid in the second trimester, and
with no history of prior gynecological surgeries.
Placenta accreta spectrum is an unusual
cause of uterine rupture and antepartum hemor-
rhage. Usually, uterine rupture happens in a
scarred uterus following some degree of trauma
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Cor Illumina, Volume 1, Issue 1, September 2021
(9). Pregnant women complaining of severe ab-
dominal pain can have several differential diagno-
ses. As for our case, since the patient was only in
the second trimester of pregnancy, the considera-
tions were Acute Appendicitis, Preterm Labor, Ab-
ruptio placenta or Urinary Tract Infection. In a
similar case reported in our country by
Dr.Wanasen and Dr. Gamboa, their patient pre-
sented with generalized abdominal pain with a pri-
mary consideration of Acute Appendicitis with an
incidence of 1 in 500 to 1 in 635 pregnancies, which
is the most common indication for surgery in non-
obstetric conditions during pregnancy (4). As for
our patient, lower abdomen ultrasound was done to
rule out Acute Appendicitis. However, the results
showed signs suggesting Uterine Rupture with
moderate hemoperitoneum, which was an indica-
tion to perform an emergent exploratory laparoto-
my.
As seen in this case, the patient presented
with severe abdominal pain equating to a surgical
abdomen which could be due to uterine rupture.
However, this differential was not the initial prima-
ry consideration because of the absence of predis-
posing factors such as prior surgery or trauma to
the uterus. During laparotomy, the placenta was
encroaching on the serosal layer of the uterus caus-
ing disruption in the myometrial integrity and lead-
ing to uterine rupture.
Uterine rupture or intra-abdominal hemor-
rhage prior to delivery is an uncommon complica-
tion of placenta accreta spectrum. Rarely, too, does
it occur in the second trimester of pregnancy (10)
and more than ten weeks from term. No other
case of uterine rupture secondary to a morbidly ad-
herent placenta with no prior history of predispos-
ing surgical trauma was recorded in our institution
in the last five years.
Management of placenta accreta spectrum is
varied depending on the severity of the attachment
of the placenta. Treatment usually involves hyster-
ectomy but in cases where future fertility is desired,
conservative management such as hypogastric or
internal iliac artery ligation, or embolization is pre-
ferred. Because of the cardiovascular compromise
that was present in this case with the patient pre-
senting with hypotension and tachycardia, and the
lack of early antenatal diagnosis, hysterectomy be-
came the most practical course of management at
the time.
Conservative management may be em-
ployed to avoid peripartum hysterectomy, its
associated consequences and maternal morbidity
including the subsequent loss of fertility. As previ-
ously mentioned, four types of conservative man-
agement can be done for morbidly adherent placen-
ta namely, (1) extirpative treatment involving man-
ual removal of placenta, (2) expectant management
or leaving the placenta in situ, (3) one step con-
servative surgery wherein the accrete area is ex-
cised, and (4) Triple-P procedure where suturing
around the accrete area after resection is performed
(11). The definitive management of placenta
A
B
C
Figure 4. Microscopic examination of the specimen. (a,b) Scanning & low power view of placenta increta showing the chorionic villi in direct contact with the myometri-
um. On higher magnification (c), no Nitabuch layer not-ed the between chorionic villi and the myometrium.
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Cor Illumina, Volume 1, Issue 1, September 2021
accreta spectrum is hysterectomy. The decision
regarding management of such cases depends
mainly on the hemodynamic status of the patient
(2). As seen in our case, the patient already had
severe anemia secondary to severe blood loss. Hys-
terectomy was done to prevent further hemor-
rhage and cardiovascular compromise.
CONCLUSION
Morbidly adherent placenta is a condition
that is catastrophic because it poses a great risk for
hemorrhage. Frequently, it can cause loss of re-
productive function as a consequence of surgical
intervention. In this case of a young primigravida,
there was a morbidly adherent placenta which re-
sulted in a loss of reproductive function because of
the removal of her uterus. Management of unusual
and difficult cases like this could be done conser-
vatively with early diagnosis and adequate plan-
ning with the involvement of a multi-specialty
team that includes anesthesiology and pediatrics,
with a better chance of a more positive outcome
for both the mother and the fetus. Prenatal check-
up and an earlier diagnosis of a placenta accreta
spectrum are important as this may lead to re-
duced fetal and maternal morbidity.
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