Right Ovarian Pregnancy Following Embryo Transfer with Right Tubal Obstruction

Dear Editor, Ovarian pregnancy represents a rare yet clinically significant form of ectopic gestation, accounting for merely 0.5%–3.5% of all ectopic pregnancies.[1] Its incidence is further reduced in the context of assisted reproductive technology (ART), including in vitro fertilization (IVF).[2,3] Nonetheless, such atypical presentations remain a critical diagnostic consideration, particularly in patients with pre-existing tubal pathology.[4] We report a distinctive case of right-sided ovarian pregnancy following transcervical frozen embryo transfer (FET) in a patient with documented total obstruction of the right fallopian tube – an anatomical anomaly which, paradoxically, did not preclude implantation on the ipsilateral ovary. The patient, a 37-year-old female with a 6-year history of primary infertility, underwent IVF following the identification of right tubal occlusion by prior hysterosalpingography. After controlled ovarian stimulation and cryopreservation of blastocysts, a single embryo was transferred in a hormonally primed FET cycle. Serum β-hCG levels demonstrated a rising trajectory – indicative of implantation – yet transvaginal ultrasound at 7 weeks showed no intrauterine gestational sac. The patient subsequently presented with acute right lower quadrant pain, anemia (hemoglobin 8 g/dL), and sonographic findings suggestive of a complex adnexal mass with hemoperitoneum. A presumptive diagnosis of ectopic pregnancy was made.[5,6] Diagnostic laparoscopy revealed an actively bleeding right ovarian pregnancy [Figure 1]. A meticulous wedge resection was performed using bipolar diathermy, with deliberate avoidance of suturing to preserve ovarian parenchyma and vascular integrity. Histopathological examination confirmed the presence of chorionic villi embedded within ovarian stroma, consistent with primary ovarian gestation.[7] The patient’s postoperative course was uneventful, with serial β-hCG levels declining to undetectable, and preserved ovarian morphology on subsequent follow-up.Figure 1: Blood Collection in the Cul De Sac. Arrow: Hemoperitoneum in the pouch of DouglasThis case prompts reflection on the mechanisms underlying ectopic implantation in ART. Prior literature postulates that elevated progesterone levels, increased ovarian vascularity following stimulation, and the technical nuances of embryo transfer may facilitate retrograde migration and aberrant implantation.[3,8] Of particular note is the implantation in the obstructed adnexal side – a phenomenon that eludes straightforward anatomical explanation. Hypotheses include retrograde migration via the contralateral patent tube followed by transperitoneal transport or yet unidentified chemotactic or molecular signaling cues favoring the ipsilateral ovary [Figure 2].[9,10]Figure 2: Abnormal pregnancy implantation. Arrow: Right ovarian ectopic pregnancyOur center, with over two decades of ART experience, has encountered only a single instance of ovarian ectopic gestation. This underscores both the rarity and the diagnostic challenge inherent to such presentations. The sonographic appearance may closely mimic that of a corpus luteum, particularly in fresh embryo transfers. However, in this FET case, the absence of follicular activity before transfer provided diagnostic clarity, further highlighting the importance of thorough luteal assessment before embryo transfer.[11] Energy-based excision techniques without suturing have demonstrated significant benefits in preserving ovarian function and fertility following ovarian ectopic pregnancy resection. By precisely excising the affected tissue and minimizing thermal and mechanical trauma, these methods allow for meticulous removal of the gestational tissue while deliberately avoiding suturing, which can compromise vascular integrity and healthy ovarian parenchyma. It also reduces the risk of postoperative fibrosis and preserves ovarian morphology, thereby maintaining the patient’s reproductive potential and supporting future fertility prospects.[12] In conclusion, this case exemplifies a rare clinical entity requiring a high index of suspicion in ART patients presenting with atypical symptomatology and inconclusive early pregnancy imaging. Prompt surgical intervention with fertility-preserving techniques remains the cornerstone of management. Further exploration of the pathophysiological mechanisms behind such anomalous implantations is warranted, particularly as ART indications expand and procedural nuances evolve. Ethics statement The study was conducted in accordance with the Declaration of Helsinki and was approved by the Institutional Review Board of RSIA Stella Maris Women’s & Children’s Hospital with (approval number: 098/Dir/RSIA.SM/IV/2025). The informed consent was obtained from the participants. Author contributions Conceptualization, Binarwan Halim and Sutan Chandra; Methodology, Sutan Chandra; Software, Sutan Chandra; Validation, Edward Muljadi; Formal analysis, Edward Muljadi; Investigation, Edward Muljadi; Resources, Sutan Chandra; Data curation, Sutan Chandra; Writing – Original draft preparation, Sutan Chandra; Writing – Review and editing, Edward Muljadi; Visualization, Edward Muljadi; Supervision, Binarwan Halim; Project Administration, Edward Muljadi; All authors have read and agreed to the final version of the manuscript. Data availability statement Data sharing is not applicable to this article as no datasets were generated or analyzed during the current study. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.