Ectopic pregnancy (EP) has been estimated to complicate
approximately 2% of pregnancies. Intramural pregnancy
(IMEP) refers to a pregnancy located within the uterine wall,
completely surrounded by myometrium and separate from
the uterine cavity. This type of pregnancy is extremely rare,
and constitutes less than 1% of EP. It was first reported by
Doederlein et al in 1913 .
The etiology of intramural pregnancy is unclear and may result
from increased lytic activity of the syncitiotrophoblast,
which allows the conceptus to penetrate the myometrium.
The most important risk factor is a previous uterine trauma
(ie: surgical or infectious origin), resulting in a sinus tract
within the endometrium (ie: previous dilatation and curettage,
c-section, or myomectomy). Also the implantation on a
focus of intramural adenomyosis or from a difficult embryo
transfer following in vitro Fertilization .
As the pregnancy progresses, the gestational sac bulges from
the serosal surface of the uterus with progressive thinning of
the myometrium. This may lead to a uterine rupture and the
need for a hysterectomy, thus, early diagnosis is important
. The development of a variety of conservative measures
has reduced the need for surgical intervention . We report
a case of intramural pregnancy with a viable embryo, in a
woman who was treated medically with systemic methotrexate
A 33 years old patient, gravida 2, para 1, was seen in our
Service for vaginal bloddy staining at 8 weeks gestation. A
transvaginal pelvic ultrasound was performed (Figure 1).A
diagnosis of intramyiometrial pregnancy was made. The Beta-
HCG level was 31.000 UI/l.
In view of her parity and future fertility, it was decided to
manage the patient medically with methotrexate, in order to
reduce trophoblastic activity and improve conditions for conserving
surgery. Two doses of 50mg of methotrexate (MTX)
were administered intramuscularly with four days apart.
A new transvaginal ultrasound was made one week later. It
still remains an intramyometrial GS, containing a not viable
embryo, who measured 21 mm, who showed absence
of cardiac activity. The Beta-HCG level was 13.000 UI/l. We
decided to perform a manual intrauterine aspiration and the
patient was discharged the next day with no further complications.
The products of conception were sent for histological
analysis. Histological review demonstrated that the specimen
contain chorionic tissue.
A repeated weekly scans demonstrated the same findings but
the pregnancy sac was regressing. The Beta-hCG level was
less than 10 on eight week after surgical approach, while the
sac still remains, but in regression.
Diagnosis of IMEP is difficult with imaging techniques, often
leading to misdiagnosis. Consequent late management
exposes women to risk of uterine rupture and indeed most
cases of IMEP are only diagnosed during the surgical management
of unexpected and weird uterine rupture during first
trimester pregnancy .
The standard non-surgical treatment of ectopic pregnancy is
intramuscular MTX injection which is associated with a high
success rate of up to 87 %. However, previous studies have
demonstrated that intramuscular MTX is less effective for
ectopic pregnancies in less common locations including cervical,
cornual, interstitial, cesarean scar and intramyometrial
sites especially when detected late .
Intramyometrial pregnancy is a very weird type of ectopic
pregnancy and it should be kept in mind by ob-gyn because
it can become a life threatening condition. Early diagnosis is
therefore very important, since it makes conservative treatment
possible and helps to preserve fertility.
1Verghese T, Wahba K, Shah A (2012) An interesting case of
intramyometrial pregnancy. BMJ Case Rep.
2Boukhanni L, Ait Benkaddour Y, Bassir A, Aboulfalah A,
Asmouki H, et al A Rare Localization of Ectopic Pregnancy: Intramyometrial Pregnancy in Twin Pregnancy following IVF.
Case Rep Obstet Gynecol
3Ong C, Su LL, Chia D, Choolani M, Biswas A (2010) Sonographic
diagnosis and successful medical management of an intramural ectopic pregnancy. J Clin Ultrasound 320-324.
4Cohen J, Kolanska K, Zanini-Grandon AS, Belghiti J,
Thomassin-Naggara I, et al. (2016) Treatment of Intramyometrial Pregnancy by In Situ Injection of Methotrexate. J Minim