To explore the clinical manifestations, diagnosis, treatment options, and maternal and infant outcomes of pulmonary embolism in early and middle pregnancy.

Based on the clinical data of 1 case admitted to Peking University Shenzhen Hospital and 18 cases reported in domestic and international literature of pulmonary embolism before 20 weeks of gestation, the treatment plans and maternal and infant outcomes were retrospectively analyzed.

The patient was a 26-year-old woman at 18^{+ 2} weeks of gestation, admitted to the Department of Respiratory Medicine, Peking University Shenzhen Hospital on April 28, 2022, with a complaint of " chest distress for 15 hours". Chest CT pulmonary angiography suggested acute massive pulmonary embolism, and heparin was administered for anticoagulation. On the morning of April 30, the condition was considered stable, and the treatment was switched to enoxaparin sodium. However, that night, chest distress and dyspnea recurred with increased pulmonary artery pressure. Emergency interventional thrombectomy and thrombolysis were performed. After the procedure, severe antithrombin Ⅲ deficiency (activity 24%) complicated by heparin resistance occurred. After infusion of fresh frozen plasma, adjustment of unfractionated heparin dosage, and bridging with warfarin, the patient improved and was discharged. The pregnant woman was admitted for delivery at 39^{+ 5} weeks of gestation on September 26, 2022. On September 28, a cervical dilation balloon was placed followed by intravenous oxytocin for induction of labor, and she eventually delivered a healthy live infant vaginally. A total of 18 cases of pregnant women with pulmonary embolism within 20 weeks of gestation were identified from the PubMed literature. Together with the present case, the clinical manifestations in the 19 cases were as follows: dyspnea (13/19), chest pain/chest tightness (9/19), syncope/unconsciousness (3/19). Among these 19 patients, 16 were diagnosed by chest CT, CT pulmonary angiography, or lung ventilation/perfusion scan, 2 by transthoracic echocardiography, and 1 did not mention the examination method. Of these, 14 patients received heparin or low-molecular-weight heparin before thrombolysis or surgery. Three cases underwent pulmonary embolectomy, 10 received systemic thrombolysis, and 6 received catheter-directed therapy.

Common clinical manifestations of pulmonary embolism in pregnancy include dyspnea and chest pain, and diagnosis mainly relies on CT pulmonary artery angiography. Treatment should follow the principle of individualization and be decided by a multidisciplinary team. For patients with hemodynamic instability or high risk, catheter-directed therapy can be considered as a priority reperfusion strategy because of its high efficiency and relatively low bleeding risk. Standard anticoagulant management and perinatal planning are key to achieving good maternal and infant outcomes.