ovarian ectopic pregnancy
The ovary is the anatomic site of less than 3% of ectopic pregnancies .
Patients present with abdominopelvic pain during the first trimester (usually 6-10 weeks gestational age) .
Risk factors include:
- pelvic inflammatory disease
- intrauterine contraceptive device use
- in vitro fertilisation-embryo transfer
- previous adnexal surgery
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 . 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: