Ovarian ectopic pregnancy
Citation, DOI & article data
The ovary is the anatomic site of less than 3% of ectopic pregnancies 5.
Patients present with abdominopelvic pain during the first trimester (usually 6-10 weeks gestational age) 6.
Risk factors include:
- pelvic inflammatory disease
- intrauterine contraceptive device use
- in vitro fertilisation-embryo transfer 3
- previous adnexal surgery 4
Pathogenesis is debated with proposed mechanisms including:
- fertilisation of the ovum in the distal fallopian tube and secondary implantation within the ovary
- failure of extrusion of the follicle
Transvaginal pelvic ultrasound demonstrates an adnexal mass or cyst with a wide echogenic outer ring, either on or within the ovary 5,6. Pressure applied via the probe is unable to separate the mass from the ovary. Color Doppler may reveal a hypervascular rim (ring of fire sign). A yolk sac or embryo are uncommonly seen.
Treatment and prognosis
Like for tubal pregnancy, treatment of ovarian pregnancy is usually treated with surgical resection of the involved organ (here, oophorectomy, or wedge resection of the ovary). Medical management has been reported but realistically is reserved for cases where there is persistent trophoblastic tissue.
In a pregnant woman without identifiable intrauterine gestational sac, an ovarian ectopic pregnancy may be misdiagnosed as the following entities that are far more common:
- 1. Seinera P, Di gregorio A, Arisio R et-al. Ovarian pregnancy and operative laparoscopy: report of eight cases. Hum. Reprod. 1997;12 (3): 608-10. doi:10.1093/humrep/12.3.608 - Pubmed citation
- 2. Einenkel J, Baier D, Horn LC et-al. Laparoscopic therapy of an intact primary ovarian pregnancy with ovarian hyperstimulation syndrome: case report. Hum. Reprod. 2000;15 (9): 2037-40. doi:10.1093/humrep/15.9.2037 - Pubmed citation
- 3. B Refaat, E Dalton, W L Ledger. Ectopic pregnancy secondary to in vitro fertilisation-embryo transfer: pathogenic mechanisms and management strategies. (2015) Reproductive Biology and Endocrinology. 13 (1): 30. doi:10.1186/s12958-015-0025-0 - Pubmed
- 4. Zhu Q, Li C, Zhao WH, et al. Risk factors and clinical features of ovarian pregnancy: a case-control study. (2014) BMJ open. 4 (12): e006447. doi:10.1136/bmjopen-2014-006447 - Pubmed
- 5. Lin EP, Bhatt S, Dogra VS. Diagnostic clues to ectopic pregnancy. (2008) Radiographics : a review publication of the Radiological Society of North America, Inc. 28 (6): 1661-71. doi:10.1148/rg.286085506 - Pubmed
- 6. Comstock C, Huston K, Lee W. The ultrasonographic appearance of ovarian ectopic pregnancies. (2005) Obstetrics and gynecology. 105 (1): 42-5. doi:10.1097/01.AOG.0000148271.27446.30 - Pubmed