Background: Intramural pregnancy (IMP) is a special type of ectopic
pregnancy. The cause of the disorder nor a uniform effective treatment plan,
either pharmacological or surgical treatment, has been reported. Pharmacological
treatments have been associated with poor clinical outcomes and a higher risk of
bleeding during treatment. Laparoscopic surgery for intramural pregnancy has been
reported and timely diagnosis and early treatment by laparoscopy can reduce the
adverse impact on female fertility. However, the safety and efficacy of
laparoscopic treatment of intramural pregnancy has not been adequately evaluated.
Methods: To evaluate the effectiveness of laparoscopic therapy of
intramural pregnancy, we retrospectively selected clinical data from 12 patients
with IMP treated by laparoscopy in our gynecology department (From January 2010
to December 2021). We collected clinical data from medical records, including:
maternal age, gestational sac location, duration of amenorrhea, clinical
symptoms, previous surgical history, pregnancy history, serum
Intramural pregnancy (IMP) is defined as a fertilized egg that has implanted in the myometrium and surrounded by myometrial tissue  and not in direct communication with uterine endometrium. The incidence is less than 1/100 of pregnancies . The common types of ectopic pregnancy are tubal pregnancy, cervical pregnancy, cornual pregnancy, ovarian pregnancy whilst intramural pregnancy is an uncommon type of ectopic pregnancy . During intramural pregnancy the gestational sac is located within the muscular wall of the uterus and may present with symptoms of amenorrhea, abdominal pain, vaginal bleeding and hemorrhagic shock. The symptoms can be severe and acute, and can be confused with ectopic pregnancy and trophoblastic disease . Intramural pregnancies are rare but dangerous, early diagnosis and timely treatment can reduce damage to the uterus, decrease the incidence of bleeding and protect a women’s fertility .
At present there are several therapeutic options for treatment of intramural pregnancy, both surgery and medication are available . Pharmacological interventions include medication with mifepristone and methotrexate, mifepristone antagonizes progesterone and causes degeneration and necrosis of the meconium and chorion, methotrexate inhibits trophoblast cells and also kills the chorion and destroys embryonic tissue . Several surgical methods have been reported, including transabdominal surgery, hysteroscopic surgery  and laparoscopic surgery . Laparoscopic surgery has the benefit of less trauma and rapid postoperative recovery in addition to sutures in the myometrium that will reduce the risk of uterine rupture in a subsequent pregnancy . Hysteroscopy can also be used to treat intramural pregnancy. The hook electrode can cut the endometrial layer and myometrium layer through the sinus tract and electrosurgery can cut the intramural pregnancy tissue. This method reduces the damage to the endometrium and is suitable for patients who wish to maintain fertility as hysteroscopy is also feasible for patients with implantation close to the endometrial layer. This manuscript analyzes the medical records of laparoscopic and hysteroscopic treatment of intramural pregnancy in our institution. A total of 12 patients with intramural pregnancy were collected and the advantages and disadvantages of laparoscopic and hysteroscopic treatment of intramural pregnancy were systematically evaluated.
A retrospective study was conducted in the Department of Gynecology in Chongqing
Health Center For Women and Children, with the approval of the Institutional
Ethics Committee. Twelve patients diagnosed with intramural pregnancy from 1st
January 2010 to 31st December 2021 at Chongqing Health Center For Women and
Children were selected. Data were collected from medical records of the patients.
The data collected included maternal age, duration of pregnancy, preoperative
ultrasound report, ultrasound gestational sac size, intraoperative sac location,
preoperative and postoperative serum
All patients had a history of amenorrhea, 8 patients had vaginal bleeding, 3 patients had lower abdominal pain, 6 patients had undertaken embryo transfer, 10 patients had a history of miscarriages and 2 patients had never been pregnant but had undergone hysteroscopy. All cases collected at our institution had a history of intrauterine surgery (Table 1).
|NO.||Age||Obstetric history||Gestational age (days)||Gestational/mixed Echo mass (cm)||Clinical symptoms||Risk factors||Location of pregnancy (ultrasound)|
||Vaginal bleeding||History of 2 artificial abortion, cesarean section||Right cornu of uterus|
||Abdominal pain||Endometrial polyp extraction||Posterior wall of uterus|
||No||Endometrial polyp extraction||Right posterior wall of uterus|
||Vaginal bleeding||History of 3 artificial abortion||Right cornu of uterus|
||No||Hysteroscopic adhesion separation||Right lateral wall of uterus|
|6||26||G4P0||120 days after ectopic pregnancy||NA/4.9
||No||Hysteroscopic adhesion separation||Left lateral wall of uterus|
|7||30||G0P0||27 days after embryo transfer||NA/2.1
||No||Embryo transfer||Left cornu of uterus|
|8||26||G2P0||27 days after embryo transfer||3.0
||No||Embryo transfer||Right cornu of uterus|
|9||32||G2P0||40 days after embryo transfer||2.3
||No||Embryo transfer||Right posterior wall of uterus|
|History of hystero-laparoscopy|
|10||30||G2P0||28 days after embryo transfer||NA/1.1
||No||History of hystero-laparoscopy||Right posterior wall of the uterus|
|11||29||G1P0||28 days after embryo transfer||1.3
||No||Ectopic pregnancy embryo transfer||Left cornu of uterus|
|12||30||G0P0||28 days after embryo transfer||2.8
||No||embryo transfer||Right cornu of uterus|
All patients were subjected to a 3D transvaginal ultrasound. In the subsequent
report, 6 cases indicated cornual pregnancy with the gestational sac located
within the myometrium near the cornu but separate from the endometrial lining as
seen by 3D transvaginal ultrasound. The other 6 cases reported gestational sacs
located in the lateral wall of uterus. All patients underwent preoperative serum
All patients underwent laparoscopy and 5 patients underwent hysteroscopy combined with laparoscopy. No gestational sac was found in the uterine cavity in hysteroscopy, so laparoscopic surgery was performed. Intraoperative laparoscopic findings of a prominent mass in the uterine wall with no suspicious pregnancy masses in the bilateral fallopian tubes, ovaries or abdominal cavity, we selected representative ultrasound and operation image (Fig. 1).
Ultrasound pictures and surgical pictures. (A) Three-dimensional ultrasound image, demonstrated a gestational sac in myometrium, not connected to the uterine cavity. (B) In laparoscopic surgery, the gestational sac was found to be located in the myometrium.
Clinical indicators included maternal age, pregnancy and
delivery history, gestational age, clinical symptoms, location of pregnancy sac
as suggested by 3D transvaginal ultrasound, location of pregnancy sac found
during surgery, preoperative and postoperative serum
|NO.||Surgical method||Intraoperative blood loss||Laparoscopy finding||Hysteroscopy finding||Postoperative Hospital stays|
|1||Laparoscopy||50 mL||Fundal myometrium||–||5824.9||1819.5||5|
|2||Laparoscopy||50 mL||Posterior wall of the uterus, pelvic hemorrhage 700 mL||–||59,382.4||12,766.4||5|
|3||Laparoscopy + Hysteroscopy||50 mL||Right cornu within the myometrium||Normal||64,898||2148.4||5|
|4||Laparoscopy||30 mL||Right cornu within the myometrium||–||2661.3||952.5||8|
|5||Laparoscopy + Hysteroscopy||50 mL||Right cornu within the myometrium||Normal||14,859.7||3597.8||4|
|6||Laparoscopy + Hysteroscopy||50 mL||Left cornu within the myometrium||Intimal defect of left uterine cornu||2.2||4|
|7||Laparoscopy||100 mL||Left cornu within the myometrium||–||10,078.6||442.9||7|
|8||Laparoscopy||50 mL||Right cornu within the myometrium||78,968||11,041||5|
|9||Laparoscopy + Hysteroscopy||30 mL||Right cornu within the myometrium||Right posterior wall of uterus is raised||23,381||1822.4||4|
|10||Laparoscopy||50 mL||Right cornu within the myometrium||–||6971.6||272||9|
|11||Laparoscopy||50 mL||Left fundal myometrium||–||33,760.3||32,345.1||5|
|12||Laparoscopy||50 mL||Right cornu within the myometrium||–||169,810||214,733||5|
In this study 12 patients had a history of uterine operations whilst 3 patients
had never been pregnant. Two patients had a history of hysteroscopic surgery and
the other 10 patients had one or more previous pregnancies. Six patients
conceived by embryo transfer. Six cases indicated cornual pregnancy with a
gestational sac located within the myometrium near the cornu but separate from
the endometrial lining as seen by 3D transvaginal ultrasound. The other 6 cases
showed gestational sacs located in the lateral wall of uterus. All patients had
successful laparoscopic removal of the chorionic tissue from the uterus. Average
blood loss 50.9
The etiology of intramural pregnancy is unclear , according to available literature relevant factors include damaged or defective endometrium, induced abortion and cesarean delivery that can lead to endometrial injury . The fertilized egg implants in the muscular wall or uterine scar of the damaged endometrium with the formation of a sinus tract and false canal due to previous uterine surgery. Many patients have a history of cesarean section and induced abortion . Other causes include adenomyosis where the ectopic endometrium deep in myometrium produces metaphase morphology through estrogen and progesterone which becomes a potential site for egg implantation and the embryo enters the myometrium by an ectopic endometrial sinus . In addition a defective uterine serous membrane as result of pelvic surgery and serious inflammation leads to the destruction of serous membrane. Once the zygote is free from the fallopian tube it travels in the pelvic cavity and is implanted in the uterine membrane defect and into the myometrium. During in vitro fertilization (IVF), a “false path to implantation” may be formed in the myometrium if the embryo transfer is difficult . This allows the fertilized egg to implant in the myometrium and in our report, we identified 6 patients with a history of in vitro fertilization. Finally there is a hypothesis that trophoblast cell activity is enhanced and decidual defense is weakened resulting in ectopic pregnancy. All 12 patients in this study had at least one of the above risk factors, 6 patients had experienced an embryo transfer.
In the past, because of the special location of intramural pregnancy, it was not diagnosed until the occurrence of uterine rupture. In recent years with the development of ultrasound, especially the use of transvaginal ultrasound, it is possible to reach a timely diagnosis of this condition before surgery. We determined the following ultrasound features of intramural pregnancy: (1) the gestation sac was completely surrounded by the myometrium; (2) the endometrial cavity and fallopian tube were not connected. Three-dimensional ultrasound shows the relationship between the gestational sac and endometrial cavity, as well as the association of endometrial and uterine myometrium that allows a clear visualization of endometrial myometrial junction, and Color Doppler flow imaging shows abundant blood flow with low resistance .
There are several treatments for intramural pregnancy, including conservative treatment with methotrexate drug therapy, surgical methods including laparotomy, hysteroscopic and laparoscopic surgery, laparotomy which is rarely used due to the severity of the trauma and slow recovery . For gestational sacs with small gestational age, small mass and thin serosal layer, laparoscopic removal of intrauterine pregnancy can be safely performed. Laparoscopic surgery is characterized by minimal trauma, rapid postoperative recovery, and the possibility of suturing the myometrial wound to reduce the risk of subsequent pregnancy rupture. Auer-schmidt reported hysteroscopic treatment for intramural pregnancy , as the hook electrode can cut the mucosa and muscle of uterus by the false tract, and gradually cut the pregnancy tissue between the muscle tissue walls, thus reducing the damage to the endometrium in those with future fertility needs. Hysteroscopic surgery is characterized by less trauma, less bleeding and faster recovery for those with pregnancy sac implantation close to the mucosa. In this paper, 5 patients were first selected for hysteroscopy, but the location of the gestational sac was not found during the procedure, so they were converted to laparoscopic surgery to open myometrium and successfully locate the sac and remove the chorionic villi.
We describe 12 extremely rare cases of ectopic pregnancy. According to
statistics of the 12 patients, the average blood loss is 50.9
The datasets used during the current study are available from the corresponding author on reasonable request.
HX conceived of the study and wrote the article. JH collected the data and analyzed the data; BL conceived the topic of the article, design the paper structure, interpreted and analyzed the data, and edited the article. All authors contributed to editorial changes in the manuscript. All authors have participated sufficiently in the work and agreed to be accountable for all aspects of the work. All authors read and approved the final manuscript.
The study was conducted in accordance with the Declaration of Helsinki, and the protocol was approved by the Ethics Committee of 044(2021). All participants gave written informed consent prior to entering the study.
We would like to express my gratitude to all those who helped me during the writing of this manuscript.
This research was funded by Women and Children’s Hospital of Chongqing Medical University, grant number 2020YJMS10. This research was funded by Chongqing Science and Technology Commission, grant number CSTB2022NSCQ-MSX0907.
The authors declare no conflict of interest.
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