A Rare Complication during Vaginal Delivery, Hamman's Syndrome: A Case Report and Systematic Review of Case Reports.

We conducted a comprehensive search of four databases for published papers in all languages from the beginning to 1 September 2021; Results: We included 76 papers with a total of 80 patients. A total of 76% patients were young primiparous, with a median age of 24 ± 5.4 years. The median gestational age was 40 ± 2.4 weeks, with a median duration of labor of 7.4 ± 4.2 h. In 86%, the ethnic origin was not specified. SPM develops in 55% of cases during the second stage of labor. Subcutaneous swelling and subcutaneous emphysema were present in 91.4%. Chest pain and dyspnea were present in 51.4% and 50% of the patients, respectively. We found that 32.9% patients had crepitus, and less common symptoms were dysphonia and tachycardia (14.3% and 14.3%, respectively). Oxygen and bronchodilators were used in 37.7% of the cases. Analgesics or sedatives were administered in 27.1%. Conservative management or the observation was performed in 21.4% and 28.6%, respectively. Antibiotics treatment was offered in 14.3%, whereas invasive procedures such as chest-tube drainage were used in just 5.7% of patients. There were no complications documented in most SPM (70.0%). We found that 16.7% of the SPM developed a pneumothorax and 5% developed a pneumopericardium.; Conclusions: In pregnancy, SPM occurs as subcutaneous swelling or emphysema during the second stage of labor. The treatment is usually conservative, with oxygen and bronchodilators and a low sequela rate. A universal consensus on therapy of spontaneous pneumomediastinum in pregnancy is necessary to reduce the risk of complications.