Spontaneous recurrent pneumothorax after in vitro fertilization

Catamenial pneumothorax (CP) is a rare form of spontaneous pneumothorax occurring within 72–96 hours before or after the onset of menstruation, accounting for approximately 3–6% of cases, and is commonly associated with thoracic endometriosis. It typically affects women over 31 years of age and predominantly involves the right hemithorax, although atypical presentations may occur. We report the case of a 39-year-old woman with secondary infertility and multiple failed in vitro fertilization (IVF) attempts who developed recurrent spontaneous pneumothorax temporally associated with exogenous estrogen therapy during endometrial preparation. Initial IVF treatment resulted in a biochemical pregnancy; however, during preparation for a donor oocyte cycle with oral estradiol, she presented with acute chest pain and dyspnoea and was diagnosed with left-sided pneumothorax, managed conservatively. Recurrence was noted upon re-exposure to estrogen, with imaging confirming left upper lobe involvement. In view of this, a modified protocol using gonadotropin-releasing hormone agonist downregulation followed by transdermal estrogen was employed, after which embryo transfer was successfully performed, resulting in a twin pregnancy with an uneventful antenatal course and delivery at 35 weeks. This case highlights an atypical presentation of recurrent pneumothorax likely influenced by hormonal therapy, raising the possibility of occult thoracic endometriosis or estrogen-mediated pleural pathology. Recognition of this association is essential for optimizing management, and individualized, multidisciplinary approaches are recommended in the absence of standardized guidelines.