Idiopathic spontaneous haemoperitoneum at 4 weeks gestation.

A 20-year-old nulliparous patient with acute-onset abdominal pain and imaging suggestive of haemoperitoneum was admitted for observation. Though, initially, haemodynamically stable, her clinical picture worsened throughout her hospitalisation and warranted two separate laparoscopies that revealed 1200 mL and 50 mL of haemoperitoneum, respectively, without an identifiable bleeding source. After serial β-human chorionic gonadotropin levels and ultrasound confirmation of a viable pregnancy 23 days later, the patient underwent a normal antenatal course and delivered a healthy infant at 37 weeks gestation. This unusual case highlights the need to consider spontaneous haemoperitoneum in pregnancy as a diagnosis, particularly in the setting of pregnancy of unknown location, even at an early stage of pregnancy.