Diagnostic Discordance in Recurrent Pregnancy Loss: Hysteroscopy Resolves Ultrasound-MRI Disagreement in Septate Uterus, but Concurrent Ovulation Induction Precludes Causal Attribution of the Reproductive Outcome.

Congenital uterine anomalies are an important and potentially treatable contributor to recurrent pregnancy loss (RPL). The septate uterus is the commonest Müllerian anomaly linked to first-trimester loss, and its differentiation from the benign arcuate uterus is essential for management, yet imaging modalities may disagree. We report the case of a 23-year-old woman (G2P0A2) who presented with oligomenorrhea and two consecutive spontaneous first-trimester miscarriages. Initial transvaginal ultrasound suggested a septate uterus, whereas pelvic magnetic resonance imaging indicated an arcuate uterus, resulting in diagnostic confusion. Diagnostic hysteroscopy revealed a thick, fibrous partial septum, and simultaneous hysteroscopic septoplasty was performed. A complete RPL evaluation was not possible: antiphospholipid antibody testing, parental karyotyping, and genetic analysis of products of conception were unavailable, so alternative etiologies could not be excluded and the septum cannot be established as the sole cause of the miscarriages. Comprehensive endocrine assessment was likewise unavailable, leaving ovulatory dysfunction incompletely characterized; a lean polycystic ovary syndrome phenotype could not be excluded. Following septoplasty and subsequent ovulation induction with letrozole, she conceived and delivered a healthy male infant at term by cesarean section. Because conception occurred only after letrozole, the relative contributions of these two sequential interventions cannot be distinguished. Second-look hysteroscopy was not performed, so restoration of a normal cavity was never objectively confirmed and residual septum or intrauterine adhesions could not be excluded before conception. This case demonstrates the diagnostic value of hysteroscopy in resolving discordant imaging while emphasizing that the outcome must not be attributed to septoplasty alone.