the incidence of natural pop ranges from 1:60 000 to 1:1 500 deliveries , accounting for 3.3% of all ectopic pregnancies . since the report of the first successful human in vitro fertilization embryo transfer ( ivf - et ) cycle resulting in ectopic pregnancy , the association of ectopic pregnancy and ivf cycles has been well established . despite the increased incidence of ectopic pregnancy associated with assisted reproductive technologies , the overall prevalence of ovarian pregnancy has been estimated at 0.3% , representing 6% of all ectopic pregnancies . with new technologies being introduced for ivf - et in recent years , pop has been reported after some of these procedures . thus , 3 reports highlight pop occurrence after intracytoplasmic sperm injection ( icsi ) and blasto - cyst transfer . donor embryo transfer is a relatively new procedure and , to our knowledge , has not been reported in association with ovarian pregnancy . we report a case of pop that occurred after early donor embryo transfer in a woman with no predisposing factors for ectopic implantation . this case is unique because the ovarian implantation occurred after ovarian suppression rather than with hyperstimulation , retrieval , and formation of corpora lutea cysts as reported in prior published case reports . a 39-year - old nulligravid woman presented to our fertility center for evaluation of primary infertility . on initial examination , a transverse vaginal septum obscuring the cervix and a 1.5-cm subserosal fibroid were identified . the husband was diagnosed with azoospermia and had twice undergone testicular biopsy with insufficient spermatogenesis , preventing sperm retrieval . they elected and arranged for a donor embryo transfer at a fertility center in their home country . the patient then had an ovarian suppression with a long protocol using buserelin acetate and estradiol valerate . the initial value was only 5 iu / l on posttransfer day 14 with an increase to 11 , 27 , 47 and 653 iu / l on days 16 , 18 , 20 and 27 , respectively ( figure 1 ) . a repeat ultrasound was performed 8 days later after the patient experienced vaginal spotting with rising hcg . the hcg level reached 4811 iu / l . at that time , an ultrasonogram was significant for a 1.5 cm x 1.5 cm x 1.4 cm solid echogenic structure with reinforced vascular marking within to the left ovary suggesting primary ovarian pregnancy ( figure 2 ) . the left ovary was enlarged by a 3.0 cm x 2.0 cm heterogeneous mass consisting of several hemorrhagic bluish cysts , with a smooth external surface ( figure 3 ) . intraoperative frozen section and final histology confirmed the presence of the conception products associated with ovarian tissue . a small amount of serous fluid was in the posterior cul - de - sac . follow - up quantitative hcg levels declined appropriately and reached an undetectable level ( < 2 transvaginal ultrasound on day 40 post embryo transfer : echogenic structure with reinforced vascular marking within the left ovary . although a rare phenomenon , primary ovarian pregnancy is an important complication associated with ivf - et treatment . theoretical risk factors for ovarian implantation include reduction in tubal contractility as a result of high progesterone levels from multiple corpus lutea , ovarian hypervascularity after hyperstimulation and egg retrieval , excessive endometrial cavity distension with media during embryo transfer , a high number of the transferred embryos , and transfer of blastocyst . in contrast , the donor embryo ivf cycle requires ovarian suppression , eliminating most hypothesized risk factors . however , in our case , a high number of transferred embryos is a possible explanation of ovarian implantation . interestingly , the most frequently reported site of ovarian pregnancy is the left ovary , leaving the question of exact mechanism of retrograde embryo migration open . because the occurrence of ovarian pregnancy is difficult to predict , its early recognition is imperative in patients undergoing ivf treatment . in fact , up to 50% of primary ovarian pregnancies might be diagnosed at an asymptomatic state mainly based on a physician 's suspicion and experience , preventing serious complications such as massive hemoperitoneum . although not specific for ovarian pregnancy , abnormally low- and slow - rising hcg levels aid in early recognition of abnormal implantation . . the initial sonographic picture of ovarian pregnancy might be obscured by multiple corpora lutea cysts after hyperstimulation and egg retrieval in a standard ivf - et cycle . the decisive ultrasonographic characteristics are the visualization of gestational sac structures and the presence of fetal heart beat within the ovary . however , even the subtle sonographic findings , such as a round echogenic mass with reinforced vascular marking within the ovary and free peritoneal fluid , are consistent with ovarian pregnancy in case of ovarian suppression for donor embryo transfer ( figure 2 ) . laparoscopic management with resection of ovarian gestation and preservation of remaining ovarian tissue is the preferred treatment for ovarian pregnancy . to avoid misdiagnosis , surgical frozen section at the time of surgery additionally , successful medical management with methotrexate as an alternative to surgery and treatment for a persistent trophoblast after laparoscopic resection of ovarian gestation has been reported . however , the absence of a histopathological diagnosis needed to meet the widely accepted spiegelberg 's criteria of primary ovarian pregnancy precludes using methotrexate as the first line of treatment . it is important for clinicians and patients to recognize the possibility of developing a primary ovarian pregnancy after ovarian suppression and donor embryo transfer in an ivf program . our case demonstrates that close follow - up of abnormally rising hcg , clinical suspicion , and sono - graphic appearance of an adnexal mass can lead to the early diagnosis and successful laparoscopic ovary preserving treatment .