Cesarean Scar Ectopic Pregnancy

Abstract

Turkish Abstract

Introduction

Pregnancy in the previous cesarean (hysterotomy) scar is one of the rare forms of ectopic pregnancy. It can be seen once in 2000 pregnancies ¹. It has become more common with the increase in cesarean rates. The microscopic fistula tract that develops from the lower uterine segment into the scar is blamed for the mechanism of implantation in this area ². In this case report, a 38-year-old, gravida 3, parity 2 female patient with a cesarean scar pregnancy which is diagnosed by ultrasonographic evaluation is presented.

Case Report

A 38-year-old, gravida 3, parity 2 female patient without any complaints is referred to us from obstetrics and gynecology clinic due to pregnancy with an estimated gestational age of 6 weeks and 2 days according to the last menstrual period. Transabdominal ultrasonography demonstrates the gestational sac which is located in the anterior part of the lower uterine segment (Figure 1). 

Figure 1 Long axis transabdominal ultrasonography was revealed a gestational sac (red arrow) located in the cesarean scar and empty uterine cavity (blue arrows).

In the enlarged transabdominal ultrasonography, a fetal nidus of 7 weeks and 2 days is seen in a 28 mm gestational sac located on the incision scar (Figure 2). The patient was diagnosed with a cesarean scar pregnancy and methotrexate was started as the first-line treatment. Then the patient underwent the dilation curettage procedure.

Figure 2A A fetal nidus of 7 weeks and 2 days is seen in an enlarged view of the transabdominal ultrasonography.

Figure 2B A fetal nidus of 7 weeks and 2 days is seen in an enlarged view of the transabdominal ultrasonography.

Discussion

Pregnancy in the previous cesarean (hysterotomy) scar is one of the rare forms of ectopic pregnancy and it has become more common ¹. The clinical presentation may vary from mild vaginal bleeding in a symptomatic patient to a painful uterine rupture and hypovolemic shock. If the ß-hCG test is positive, the location of the pregnancy (intrauterine or extrauterine) should be evaluated with an ultrasound examination ³. The diagnosis can be done by observing the gestational sac in the cesarean scar which is located in the anterior part of the lower uterine segment on ultrasonographic imaging. Ultrasonographic evaluation can be done transabdominal or transvaginal ultrasonography can be preferred to obtain better resolution. Other findings on ultrasonography are the absence of pregnancy products in the intrauterine area and cervical canal, the absence or very thin myometrial tissue between the gestational sac and the bladder. It should be determined whether there is an invasion to neighboring pelvic organs such as the bladder. Magnetic resonance imaging (MRI) is highly efficacious in distinguishing the sac which is located in the cesarean scar. Although MRI and hysteroscopy can be used to evaluate the place of pregnancy, it is not necessary for diagnosis ^{4, 5}. The algorithm of the methods to be used in the diagnosis is MRI and/or hysteroscopy for advanced complications after ultrasonographic evaluation. The most appropriate treatment method for cesarean scar pregnancy is uncertain and there is no standard treatment approach. In a stable patient, treatment can be performed by dilatation and curettage or by injection of methotrexate under ultrasonographic guidance. Early diagnosis and treatment are very important to prevent serious complications. Therefore, radiologists should be familiar with the cesarean scar pregnancy.

References

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3. Graesslin O, Dedecker F Jr, Quereux C, et al. Conservative treatment of ectopic pregnancy in a cesarean scar. Obstet Gynecol. 2005;105(4):869-71.
4. McKenna DA, Poder L, Goldman M, et al. Role of sonography in the recognition, assessment, and treatment of cesarean scar ectopic pregnancies. J Ultrasound Med. 2008;27(5):779-83.
5. Dibble EH, Lourenco AP. Imaging Unusual Pregnancy Implantations: Rare Ectopic Pregnancies and More. AJR Am J Roentgenol. 2016;207(6):1380-1392.