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 .
 primary ovarian pregnancy is a rare type of ectopic pregnancy , particularly following in vitro fertilization . although there have been a few reported cases of primary ovarian pregnancy following in vitro fertilization embryo transfer , we believe this is the first report involving donor embryo transfer . 
 a high index of clinical suspicion , abnormal human chorionic gonadotropin levels , and early ultrasound evaluation may aid timely diagnosis and appropriate management . 
 this report provides a reminder to practitioners to advise patients undergoing embryo transfer of the primary ovarian pregnancy risk . 
 information is provided herein regarding the diagnosis and management of primary ovarian pregnancy in women treated with in vitro fertilization . 
 we review the criteria for early diagnosis and treatment options . 
INTRODUCTION
CASE REPORT
DISCUSSION
CONCLUSION