Ultrasonographic findings and treatment in heterotopic cesarean scar pregnancy

A very rare case of heterotopic cesarean scar pregnancy highlights the potential for cesarean scar pregnancy in patients with a history of cesarean scar.

FIGURE. Sagittal transvaginal grayscale image of the uterus, showing two gestational sacs. An embryo is present in the gestational sac, normal implantation; a yolk sac is present in the ectopic cesarean scar gestational sac.


A pregnant woman in her mid-30s presented to the emergency room with acute onset of back and pelvic pain and moderate spotting. The patient was gravida 4, para 2 (G4P2) and had had two prior cesarean sections. The pregnancy was conceived using letrozole as a fertility medication, which has a known twin risk of 3% to 7%.[1] Estimated gestational age was 5 weeks 3 days. Quantitative β-hCG level was 7190 mIU/mL at presentation and rose to 13 484 mIU/ mL 2 days later.

Imaging findings

Ultrasonography showed a gestational sac with an embryo implanted in the endometrium near the fundus and an ectopic gestational sac within the cesarean scar niche [Figure].


Imaging findings of two gestational sacs, where one sac is implanted along the cesarean scar, suggests heterotopic cesarean scar pregnancy. The patient wished to keep the intrauterine gestation; thus, a selective reduction of the cesarean scar pregnancy by ultrasonography-guided local injection of methotrexate was performed. Despite this, the patient’s β-hCG level continued to rise. Systemic treatment with methotrexate also failed to reduce the β-hCG level; therefore, a hysterectomy was performed. Heterotopic cesarean scar pregnancy was confirmed at pathology.

Heterotopic pregnancy is one of the rarest forms of multiple gestation, occurring in less than 1 in 30 000 naturally conceived pregnancies.[2] The incidence of heterotopic pregnancy increases with assisted reproductive techniques.[3] Cesarean scar pregnancy is extremely rare and accounts for only 6% of all ectopic pregnancies; however, incidences are rising with cesarean section rates.[4] Heterotopic cesarean scar pregnancy is a rare cesarean scar pregnancy combined with an intrauterine pregnancy.

Treatment for isolated cesarean scar pregnancy includes dilation and curettage, laparoscopic resection, and local or systemic administration of methotrexate.[5] Because of the low incidence of heterotopic cesarean scar pregnancy, no standard treatment protocols have been established.

Ultrasonography-guided selective embryo aspiration and/or drug injection and surgical resection have been described.[6]

Competing interests

None declared.


This article has been peer reviewed.

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.


1.    Legro RS, Brzyski RG, Diamond MP, et al. Letrozole versus clomiphene for infertility in the polycystic ovary syndrome. N Engl J Med 2014;371:119-129. Erratum in: N Engl J Med 2014;317:1465.

2.    Hassani KIM, El Bouazzaoui A, Khatouf M, Mazaz K. Heterotopic pregnancy: A diagnosis we should suspect more often. J Emerg Trauma Shock 2010;3:304.

3.    Abusheikha N, Salha O, Brinsden P. Extra-uterine pregnancy following assisted conception treatment. Hum Reprod Update 2000:6:80-92.

4.    Singh K, Soni A, Rana S. Ruptured ectopic pregnancy in caesarean section scar: A case report. Case Rep Obstet Gynecol 2012;2012:106892.

5.    Karahasanoglu A, Uzun I, Deregözü A, Ozdemir M. Successful treatment of cesarean scar pregnancy with suction curettage: Our experiences in early pregnancy. Ochsner J 2018;18:222-225.

6.    OuYang Z, Yin Q, Xu Y, et al. Heterotopic cesarean scar pregnancy: Diagnosis, treatment, and prognosis. J Ultrasound Med 2014;33:1533-1537. 


Dr Saravana-Bawan is an interventional radiologist in the Island Health Authority. Ms Letourneau is a sonographer in the Island Health Authority.

Corresponding author: Karen Letourneau, karenletourneau@me.com.

Samantha R. Saravana-Bawan, MD, FRCP, Karen Letourneau, CRGS. Ultrasonographic findings and treatment in heterotopic cesarean scar pregnancy. BCMJ, Vol. 66, No. 6, July, August, 2024, Page(s) 202-203 - Clinical Images.

Above is the information needed to cite this article in your paper or presentation. The International Committee of Medical Journal Editors (ICMJE) recommends the following citation style, which is the now nearly universally accepted citation style for scientific papers:
Halpern SD, Ubel PA, Caplan AL, Marion DW, Palmer AM, Schiding JK, et al. Solid-organ transplantation in HIV-infected patients. N Engl J Med. 2002;347:284-7.

About the ICMJE and citation styles

The ICMJE is small group of editors of general medical journals who first met informally in Vancouver, British Columbia, in 1978 to establish guidelines for the format of manuscripts submitted to their journals. The group became known as the Vancouver Group. Its requirements for manuscripts, including formats for bibliographic references developed by the U.S. National Library of Medicine (NLM), were first published in 1979. The Vancouver Group expanded and evolved into the International Committee of Medical Journal Editors (ICMJE), which meets annually. The ICMJE created the Recommendations for the Conduct, Reporting, Editing, and Publication of Scholarly Work in Medical Journals to help authors and editors create and distribute accurate, clear, easily accessible reports of biomedical studies.

An alternate version of ICMJE style is to additionally list the month an issue number, but since most journals use continuous pagination, the shorter form provides sufficient information to locate the reference. The NLM now lists all authors.

BCMJ standard citation style is a slight modification of the ICMJE/NLM style, as follows:

  • Only the first three authors are listed, followed by "et al."
  • There is no period after the journal name.
  • Page numbers are not abbreviated.

For more information on the ICMJE Recommendations for the Conduct, Reporting, Editing, and Publication of Scholarly Work in Medical Journals, visit www.icmje.org

BCMJ Guidelines for Authors

Leave a Reply