Introduction

Cesarean Scar Pregnancy (CSP) is the implantation of gestational sac in the previous cesarean scar. The prevalence of CSP varies from one in every 1800 to one in every 2216 individuals [1—3]. The possible complications of CSP, especially if it is left undiagnosed, include uterine rupture, massive bleeding and a need for emergency hysterectomy, which can lead to significant maternal morbidity. During the past decade, the medical publications represent a considerable increase in CSP reports. This increase can be attributed to the progress in diagnostic sonography, vaginal sonography and an increase in physicians’ awareness of the conditions [1]. On the other hand, the prevalence of cesarean section delivery (CS) has significantly increased during the last two decades. A meta-analysis performed in 2014 in Iran reported that the CS rate was increasing recently, which can eventually lead to higher rate of CSP. They also indicated that there was a prevalence of 48% for CS in Iran. On the other hand, due to the ethnical situation and the high desire for having several children in the family in the south east of Iran, where the study has been conducted, the rate of cesarean section is even higher [4]. It must be considered that the complication rate in CS deliveries is two to seven times higher than in the normal vaginal deliveries [5]. Based on the prior studies, cesarean operation can result in various problems, including increase in the rate of stillbirth and spontaneous abortion in later pregnancies, as well as fertility problems for mothers, such as ectopic pregnancy, infertility, reduced fertility, placenta previa, placenta accreta, placental abruption and uterine rupture [6, 7]. Placenta starts forming from 13 to 15 days following the ovulation. Natural implantation of the fertilized ovum is vital for the pregnancy’s success and this process is perfectly regulated [8]. The first case of CSP was reported in 1978 [9] and there were 161 similar cases reported until 2006 [10]. In some of the placenta accreta cases, particularly placenta percreta, which have begun under the title of CSP, it is possible to determine the subsequent trends based on the scar’s thickness and degree of invasion [11].

Case Reports

We present two cases of the abnormal invading placenta, which have been diagnosed in various pregnancy periods and were hospitalized for the same reason. We also investigate the published materials regarding the rate of CSP (table). Figure demonstrates the study selection process for further examination (fig. 1).

Management Options and Outcomes (2010—2020)

Fig. 1. Search results.

Both patients who attended our maternal-neonatal unit agreed with a sonographic examination based on a local agreement. In order to perform this retrospective analysis, the patients’ data were used anonymously and there was no need for acquiring any informed consent letters from exact person. This study has been accepted and approved by the hospital’s ethics committee. The goal of this case series was highlighting the various treatment options and outcomes regarding early CSP diagnosis.

Diverse medical and surgical methods have been suggested in the course of time about CSP treatment. The definitive success of none of them has been reported but most of the authors have supported the surgical methods as the most effective ones and the same approach was as well adopted in our unit [12]. The treatment options for CSP include, conservative medications such as the general use of methotrexate (MTX) or the topical use of sonography-guided hyperosmolar solutions [13]. The other treatment options are different types of conservative surgery along with preservation of fertility, including selective vein embolization, bilateral hypogastric vein embolization along with trophoblastic depletion [14, 15], dilation and curettage, CSP removal via hysteroscopy, laparoscopy or laparotomy [16, 17]. An essential surgical approach is removing the whole uterus which causes absolute infertility.

Case I

A 21-year-old G4P1L1(abortion ×2) woman with positive pregnancy test (B-HCG titer of 6483 IU/ml) and light bleeding attended our hospital. Five months ago, she had undergone an emergency cesarean due to the placenta abruption and transverse position during week 22 of her pregnancy. Her current gestational age was 10 w + 1 d according to LMP. On the other hand, she stated that she had regularly taken her OCP progesterone (half a milligram lynestrenol). She did not have a positive medical history or hospitalization. Transabdominal sonography revealed a heterogenous 47×46×12 mm mass and less than a millimeter thickness of the anterior wall of the uterus (fig. 2). One day later, repeated abdominal sonography was carried out by another radiologist who confirmed CSP with a size increased to 49×12×54 mm. We decided to perform sonography-guided hysteroscopic incision. The situation, the surgical process and the other risks, including the risks of possible open laparotomy, laparoscopy or hysterectomy, were explained to the patient. An informed consent letter was also acquired. At first, a hysteroscope was inserted into the uterine cavity. There was no evidence of the gestational sac. An isthmocele in the prior cesarean scar location and a clot in the uterine fundus were the only findings (fig. 3, on color sticker). Then, using a ten-millimeter laparoscopic umbilical port, an entry was made into the abdominal cavity. A vast omental plate was found between the uterus and the anterior abdominal wall (fig. 4, on color sticker). After observing the uterus, the base of the ectopic gestational sac was found. Since the patient’s previous delivery had been made at 22nd gestational week and the lower segment had not been formed (degrees 3 and 4 CSP), Kerr incision was made in a location higher than the lower segment and the ectopic pregnancy was found near the fundus. Vasopressin was injected into the gestational sac and, using a monopole, an incision was made onto the sac. The gestation products were extracted using suction and grasp. The scar of ectopic pregnancy and the isthmocele were observed through laparoscopy. One week after operation, B-HCG level was measured and it decreased to one third of the initial amount and further reached referent values.

Fig. 2. An incongruent 47×46×12 mm mass with a thinness of myometrium more than 1 mm of the anterior wall of the uterus.

Fig. 3. An isthmocele in the prior cesarean location and a clot in the uterine fundus were the only things found.

Fig. 4. A vast omental plate was found adhering between the uterus and the anterior abdominal wall.

Case II

A 39-year-old G3P2L2 (C/S× 2) woman with a 14-week menstrual delay, positive pregnancy index test and sonographic chart indicating ectopic cesarean scar pregnancy was hospitalized in our hospital. In the first sonographic examination, endometrium was found heterogenous and 16 mm thickness with hematoma between its layers. A heterogenous 37×50 mm mass with peripheral blood circulation in the lower uterus with protrusion towards the bladder was reported. Next sonographic imaging confirmed the first imaging along with an increase in the size of the mass to 52×47×49 mm. Selective hysteroscopy using a resectoscope was considered for the patient. The risk of surgery and the possibility of needing invasive methods such as laparoscopy and hysterectomy were explained to the patient, while acquiring a letter of consent from her. After entering with hysteroscope, a degree 2 CSP was observed inside the uterine cavity. The complete resection was conducted with the use of resectoscope under the guidance of sonography (fig. 5, on color sticker). After the complete hysteroscopic incision, vaginal bleeding was encountered. Due to the intensity of the uterine bleeding and the possibility of hemorrhagic shock, an intracavitary Foley catheter filled with normal saline was used and decision was made to perform laparotomy to find the bleeding source. However, we did not find the location of extensive bleeding. Due to constant bleeding, abdominal hysterectomy was carried out and the pathological results confirmed the placenta’s adhesion to myometrium (placenta accreta).

Fig. 5. EP scar resection using resectoscope.

Discussion

In this case study, it was shown that persistent CSP can be treated using hazardless conservative methods, including removing the gestational sac by laparoscopy and initial repairing of the uterine wall’s defects. Resection of the ectopic gestational sac was technically simple and it could be done within a short time associating with the least possible hemorrhage and it was also found accompanied with good recovery rates. It is assumed that blastocyst is situated in endometrium and myometrium in a region with microscopic opening inside a CS scar [18]. CSP likelihood is expected to be increased with the increase in CS rate. The clinical signs might be scarce in the initial stages of the pregnancy but later CSP can lead to the uterine rupture along with extensive bleeding, hemoperitoneum and hemorrhagic shock. E. Timor-Tritsch et al (2014) examined ten cases of termed or nearly termed CSP and found all of them having placenta accreta [19]. Moreover, K.M. Seow et al (2004) evaluated the outcomes of the pregnancies after CSP that had been treated by conservative medical methods or surgery in seven patients. Two of CSP cases and two other patients evaluated by them were diagnosed with placenta accreta (two during and two after cesarean) and they were subjected to hysterectomy [20]. In addition, J. Fatusic, et al (2019) reported a case of cervico-isthmic ectopic pregnancy as a result of remained trophoblastic tissue after vacuum aspiration; due to the intensive bleeding, the patient was subjected to hysterectomy during the second surgery and the further histopathological evaluations confirmed placenta accrete [21]. Therefore, every patient with at least one past CS should be evaluated in terms of abnormal placenta accreta symptoms that start during the first trimester of the pregnancy [22, 23]. CSP as a Placenta Аccreta Spectrum (PAS) prognosis can be diagnosed during the early week five to the week eight of the pregnancy by the lower position of the gestation sac near the cesarean scar. On the other hand, the specific signs of PAS in ultrasonography are also visible in the specialized centers. Risk classification based on the child delivery history and US findings during the first trimester can improve the delivery results and reduce the maternal mortality. Advising the patient about the advantages, risks and long-term side effects of each of the management strategies is a vital part of taking care of women with PAS disregarding the gestational age.

Conclusion

There is a spectrum of treatment choices available for treating CSP and the selection of a method can be done based on the type of CSP, pregnancy age, hemodynamic stability, medical skill and access to the equipment. The women with CSP should be warned that the decision for prolongation of pregnancy can bring to lethal and abundant bleeding, as well as to hysterectomy. The surgical treatment features a high success rate; however, there is a need for higher surgery skill and consulting with the patient about the surgical risks. Apparently, combined treatments are highly successful but their added costs and the risk of side effects are not clear in comparison to single treatments. Disregarding the treatment type, paying attention to the women’s conditions and their intentions for later pregnancies needs discussion at the time of suggesting a treatment method and it is also necessary to rigidly supervise forthcoming pregnancies.

Abbreviations: Cesarean scar pregnancy (CSP), Placenta accreta spectrum (PAS); Oral contraceptive pill (OCP), Cesarean section (CS), Methotrexate (MTX).

Participation of the authors:

Concept and design of the study — K. Sadegi, M. Kaveh

Data collection and processing — K. Sadegi, M. Kaveh

Text writing — D. Fallahi, A. Poodineh

Editing — K. Sadegi, D. Fallahi, M Kaveh, A. Poodineh

Authors declare lack of the conflicts of interests.