DOI 10.1515/crpm-2011-0006 Case Rep. Perinat. Med. 2012; 1(1-2): 11–14
Alexander Weichert*, Anke Thomas, Wolfgang Henrich, Christhardt Köhler,
Joachim W. Dudenhausen and Karim D. Kalache
Cervico-isthmic pregnancy with cervical placenta
accreta
Abstract: Cervical pregnancies are a rare form of ectopic
pregnancies. The reported incidence is estimated to
affect one in 1000 to 18,000 pregnancies. Whereas true
cervical pregnancies are rare, cervico-isthmic pregnancies are more common, and in addition more lethal as
the maternal risk for massive hemorrhage increases with
the advancement of the gestational period. Risk factors
include tubal disease, uterine surgery as well as in vitro
fertilization. We report a case of a 35-year-old woman at
20 weeks of gestation who was referred to our department because of cervical shortening and recurrent painless vaginal bleeding. Transvaginal ultrasound revealed
that the placental implantation site was located within
the cervix and the uterine isthmus while the fetus was
developing in the uterus. Furthermore, we suspected placenta accreta. After counseling expectant management
was chosen. At 31+5 weeks of gestation the patient developed severe vaginal bleeding leading to an emergency
cesarean section with hysterectomy after an unsuccessful effort to stem the hemorrhage conservatively. The
pathology report confirmed our sonographic findings. It
can be concluded that cervico-isthmic pregnancies are
rare implantation disorders that require interdisciplinary
peripartum management. Expectant management can be
offered. Preterm delivery and probable requirement of a
hysterectomy need to be discussed with the patient.
Keywords: Cervical pregnancy; cervico-isthmic pregnancy; cervix uteri; ectopic pregnancy; placenta accreta;
uterine hemorrhage.
*Corresponding author: Dr. med. Alexander Weichert, Department
of Obstetrics, Charité – Universitätsmedizin Berlin,
Campus Charité Mitte, Berlin, Germany,
Tel.: +49 30 450 664188, Fax: +49 30 450 564941,
E-mail: [email protected]
Anke Thomas and Karim D. Kalache: Department of Obstetrics,
Charité – Universitätsmedizin Berlin, Campus Charité Mitte, Berlin,
Germany
Wolfgang Henrich and Joachim W. Dudenhausen: Department of
Obstetrics, Charité – Universitätsmedizin Berlin, Campus Virchow
Klinikum, Berlin, Germany
Christhardt Köhler: Department of Gynecology, Charité –
Universitätsmedizin Berlin, Campus Charité Mitte, Berlin, Germany
Introduction
Cervical pregnancies including both true cervical and
cervico-isthmic pregnancies remain a rare implantation
disorder. The reported incidence varies from 1 in 1000 to 1
in 18,000 affecting approximately 1% of all ectopic pregnancies [2, 4].
Notwithstanding the rare incidence rate of this
anomaly the diagnostic criteria in the first trimester are
well-known. Both Oyelese et al. [5] and Strobelt et al. [6]
proposed that a true cervical pregnancy exists if the gestational sac is confined to the cervix. Other authors have
suggested that cervical pregnancy should be suspected if
there are poorly circumscribable intrauterine structures,
an enlarged uterus, absence of intrauterine pregnancy as
well as a distended cervix. The diagnosis can be made by
transvaginal ultrasound as early as 7 weeks into gestation
[1]. In contrast to cervico-isthmic pregnancy a true cervical
pregnancy with delivery at term is considered impossible.
Abnormal implantation of the placenta into the
uterine wall results in placenta accreta, increta, and
percreta. Probable risk factors for both abnormal implantation and localization include curettage, Asherman’s
syndrome, previous cesarean delivery, previous cervical
or uterine surgery, and in vitro fertilization. Complications
include damage to adjacent organs (bladder, ureters, and
bowel) and massive hemorrhage leading to cesarean hysterectomy [4].
Implantation disorders, such as placenta accreta,
increta or percreta, in cervical pregnancies are explained
by the absence of a protective decidua basalis in the cervix
which results in trophoblastic invasion into the cervical
tissue. One has to assume that there is also an elevated
risk of fetal presentation anomalies, premature rupture of
membranes or cord implantation disorders similar to placenta previa.
During the course of a pregnancy affected by cervical placenta typical clinical symptoms include painless
bleeding. After delivery the absence of contractile tissue
in the cervix can result in massive bleeding requiring a
hysterectomy. Maternal mortality has been reported as
high as 50% [1].
Unauthenticated
Download Date | 6/18/17 10:59 AM
12 Weichert et al., Cervico-isthmic pregnancy with cervical placenta accreta
However, because most cervical pregnancies abort
spontaneously or are terminated diagnostic criteria in the
second and third trimester are lacking.
We report a case about the management of a cervicoisthmic pregnancy.
Case report
A 35-year-old woman (gravida III, para I) was referred
to our department at 19+5 gestational weeks with cervical shortening. In addition, the patient reported episodes of painless vaginal bleeding during the course of
her pregnancy. Her past obstetric history showed two
miscarriages with curettages and her medical history
a Factor-V-Leiden coagulopathy. Therefore, she was
treated with low-molecular-weight heparin (Dalteparin
5000 IE, once daily s.c.). The placental implantation site was completely located in the cervix and the
uterine isthmus while the fetus developed in the uterus
(Figure 1A). Other findings of the placenta were placental lacunae and a thin myometrial layer in transvaginal ultrasound (2 mm, not shown) adjacent to the
bladder without signs of myometrial invasion suspecting placenta accreta. The remaining cervical length was
13 mm (not shown). The results of a fetal ultrasound scan
were unremarkable (GE Voluson E8 ultrasound system,
General Electric Healthcare, Waukesha, WI, USA and
Sonoace Accuvix V20 ultrasound system, Medison Co.,
Ltd., Daechi-Dong Kangnam-Gu, Seoul, Korea). We also
performed magnetic resonance imaging (MRI) (Philips
Panorama, high field open MRI, Koninklijke Philips
Electronics N.V., Eindhoven, The Netherlands) which
confirmed our sonographic findings (Figure 1B).
The patient was hospitalized for further surveillance.
After counseling, the couple opted to continue with the
pregnancy. At 23+5 weeks of gestation she received one
cycle of betamethasone for fetal lung maturation (2×12 mg
in 24 h i.m.). During hospitalization, the course of her
pregnancy was complicated by two episodes of painless
vaginal bleeding, which ceased spontaneously. To prevent
recurrent bleeding oral tocolytics (30 mg nifedipine TID)
were administered. A cesarean section was planned for
34+0 weeks of gestation. At 31+5 weeks of gestation the
patient developed brisk vaginal bleeding with sonographic signs of placental abruption and thus an emergency cesarean section by median laparotomy and fundal
transverse hysterotomy was performed, allowing the
delivery of a girl weighing 1645 g, with Apgar scores of 7 at
1 min, 5 at 5 min and 9 at 10 min (umbilical cord artery pH
7.27, base excess –1.2 mmol/L).
The placenta initially detached spontaneously except
to adherent areas leading to severe hemorrhage which
could not be stemmed by uterine stimulants resulting in
the need for a hysterectomy. The estimated overall blood
loss was 3000 mL. During surgery she received 6 units of
packed red blood cells and 8 units of fresh frozen plasma.
Her hemoglobin level after the operation was 9.3 g/dL.
After 1 day in the intensive care unit she was transferred
to the obstetric ward. The patient made a steady recovery
and was discharged on postoperative day 9.
The pathology report was consistent with our
sonographic and MRI findings, revealing a cervical
Lower uterine segment
Bladder
Cord insertion
Placenta
Figure 1 (A) Transabdominal ultrasound scan showing the location of the placental implantation site in the cervix and the uterine isthmus
leading to distension of cervical tissue (cervical region marked by white stars). (B) Corresponding T2-weighted MR image showing multiple
placental lacunae (marked by black star).
Unauthenticated
Download Date | 6/18/17 10:59 AM
Weichert et al., Cervico-isthmic pregnancy with cervical placenta accreta 13
implantation of the placenta with a thin decidual layer.
Beyond that placenta accreta was confirmed (Figure 2).
Hysterotomy
Discussion
Cervical pregnancies remain a rare implantation disorder.
Cervico-isthmic pregnancies are more common as well as
more lethal, because with advancing gestational age the
maternal risk for massive hemorrhage increases. Our case
illustrates four important points.
Owing to certain similarities cervico-isthmic pregnancies with cervical placenta can be mistaken for major
placenta previa. In major placenta previa the placental
implantation site is within the uterine cavum, whereas
cervico-isthmic pregnancies with cervical placenta (like
in our case) remain in the lower uterine segment and the
cervical region. Although in placenta previa the cervical
length is not affected, in cervico-isthmic pregnancies a
distended cervical canal is visualized [1], which can be
confused with cervical shortening.
Most cases with cervical pregnancy abort spontaneously or are terminated in early gestational age. However,
in our single case experience expectant management
with third trimester delivery was possible even with the
shortened cervix. This is because the shortened cervix
was more likely to be the result of displacement of cervical tissue than a sign of imminent premature delivery.
Implantation disorders of the placenta into the uterine
wall result in placenta accreta, increta, and percreta.
Probable risk factors include previous uterine surgery
(i.e., curettage, Asherman’s syndrome, previous cesarean
delivery) as well as in vitro fertilization. If placental growth
exceeds uterine boundaries, adjacent organs (bladder,
ureters, and bowel) may be damaged which might cause
hemorrhage leading to the requirement of a cesarean hysterectomy [4].
In early ultrasound scans, clinical findings include
visualization of products of conception in a dilated cervix.
The uterus is usually of normal size. Cervical implantation
in both true cervical and cervico-isthmic pregnancies may
be confused with the first stage of a spontaneous abortion.
Furthermore, it is important to distinguish between a true
Anterior
cervical wall
Posterior
cervical wall
Cervical placenta
Figure 2 Macroscopic image of the uterus showing the implantation site of the placenta in the cervix. The cervical canal is distended
by the placental tissue.
cervical pregnancy and a cervico-isthmic pregnancy so
that maternal risks such as uterine rupture, hemorrhage,
and hysterectomy are reduced.
From our single case experience cervico-isthmic pregnancies can be continued to the third trimester after counseling. It is important that the risk of preterm delivery as
well as severe hemorrhage and organ loss is discussed
with the patient.
Alternative strategies to prevent postpartum hemorrhage that have been published include uterine artery
embolizations as well as ligation of the uterine or internal
iliac arteries [3].
In conclusion, expectant management can be offered
to patients with a cervico-isthmic pregnancy. The risk of
preterm delivery for these patients is difficult to assess. In
our case, the timing of delivery was dependent on the incidence of vaginal bleeding.
Furthermore, our case underlines the importance of
interdisciplinary peripartum management as well as necessary skills of the delivering surgeon to control severe
hemorrhage which possibly requires hysterectomy.
Received November 22, 2011. Accepted November 28, 2011.
Previously published online February 16, 2012.
References
[1] Avery DM, Wells MA, Harper DM. Cervico-isthmic corporeal pregnancy with delivery at term: a review of the literature with a case
report. Obstet Gynecol Surv. 2009;64:335–44.
[2] Gun M, Mavrogiorgis M. Cervical ectopic pregnancy: a case
report and literature review. Ultrasound Obstet Gynecol. Case
Reports Rev. 2002;19:297–301.
Unauthenticated
Download Date | 6/18/17 10:59 AM
14 Weichert et al., Cervico-isthmic pregnancy with cervical placenta accreta
[3] Henrich W, Surbek D, Kainer F, Grottke O, Hopp H, Kiesewetter H,
et al. Diagnosis and treatment of peripartum bleeding.
J Perinat Med. 2008;36:467–78.
[4] Mesogitis SA, Daskalakis GJ, Doublis DG, Antsaklis AJ, Papantoniou NE, Michalas SP. Cervico-isthmic pregnancy: an extremely
rare case diagnosed during labour. Eur J Obstet Gynecol Reprod
Biol. 2001;98:251–2.
[5] Oyelese Y, Elliott TB, Asomani N, Hamm R, Napoli L, Lewis
KM. Sonography and magnetic resonance imaging in the
diagnosis of cervico-isthmic pregnancy. J Ultrasound Med.
2003;22:981–3.
[6] Strobelt N, Locatelli A, Ratti M, Ghidini A. Cervico-isthmic pregnancy: a case report, critical reappraisal of the diagnostic criteria, and reassessment of the outcome. Acta Obstet Gynecol
Scand. 2001;80:586–8.
The authors stated that there are no conflicts of interest regarding
the publication of this article.
Unauthenticated
Download Date | 6/18/17 10:59 AM