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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 maj_kriz@yahoo.com 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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Cor Illumina, Volume 1, Issue 1, September 2021

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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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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