Immune thrombocytopenia in the first trimester; Maternal exposure during pregnancy, first trimester; This literature-non-study prospective pregnancy case was reported in a literature article and describes the occurrence of IMMUNE THROMBOCYTOPENIA (Immune thrombocytopenia in the first trimester) in a 32-year-old female patient (gravida 1) who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Pregnant.    On an unknown date, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. Last menstrual period and estimated date of delivery were not provided. On an unknown date, the patient experienced IMMUNE THROMBOCYTOPENIA (Immune thrombocytopenia in the first trimester) (seriousness criteria hospitalization and medically significant) and MATERNAL EXPOSURE DURING PREGNANCY (Maternal exposure during pregnancy, first trimester). The patient was treated with PREDNISONE (oral) for Adverse event, at a dose of 1 mg/kg once a day. At the time of the report, IMMUNE THROMBOCYTOPENIA (Immune thrombocytopenia in the first trimester) and MATERNAL EXPOSURE DURING PREGNANCY (Maternal exposure during pregnancy, first trimester) had resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Activated partial thromboplastin time: normal (normal) normal. On an unknown date, Blood fibrinogen: normal (normal) normal. On an unknown date, Blood folate: normal (normal) normal. On an unknown date, Blood smear test: unknown (Inconclusive) notable only for thrombocytopenia on hematologic review. On an unknown date, Fibrin D dimer: normal (normal) normal. On an unknown date, Haematocrit: 41.1% (normal) 41.1%, three months prior and 38.2% (normal) 38.2%, On admission. On an unknown date, Haematology test: unknown (Inconclusive) given negative thrombocytopenia work-up, ITP was suspected as a diagnosis of exclusion. On an unknown date, Haemoglobin: 13.8 g/dl (normal) 13.8 g/dL, three months prior and 13.1 g/dl (normal) 13.1 g/dL, On admission. On an unknown date, Haptoglobin: normal (normal) normal. On an unknown date, Platelet count: 1000/ml (abnormal) 1000/mL, On admission, 268 000/ml (normal) 268 000/mL, three months prior, 6000/ml (abnormal) 6000/mL, on hospital day 2, 26 000/ml (abnormal) 26 000/mL, on hospital day 3 and 303 000/ml (normal) Patient had repeat laboratory evaluation 19 days after vaccination and was found to have recovery of her platelets to 303 000/mL. On an unknown date, Prothrombin time: normal (normal) normal. On an unknown date, Reticulocyte count: normal (normal) normal. On an unknown date, Ultrasound abdomen: normal size (normal) normal size and sonographic appearance of the spleen.. On an unknown date, Vitamin B12: normal (normal) normal. On an unknown date, White blood cell count: 8900/ml (normal) 8900/mL, three months prior and 8000/ml (normal) 8000/mL, On admission.     The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was unknown.   For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter considered IMMUNE THROMBOCYTOPENIA (Immune thrombocytopenia in the first trimester) and MATERNAL EXPOSURE DURING PREGNANCY (Maternal exposure during pregnancy, first trimester) to be possibly related.    A 32-year-old healthy G1P0 patient at 8 6/7 weeks of gestation was admitted for hospitalization in the setting of acute-onset bruising and petechiae.Additionally, no known personal or familial history of autoimmune disease. Her, ITP symptoms remained mild, limited to bruising and petechiae.  It's a case of ITP following COVID-19 vaccination in a pregnant patient in the first trimester, with resolved symptoms following treatment with oral corticosteroids. At present, a causal relationship between COVID-19 vaccination and ITP has not been established, but providers must remain vigilant to infrequent complications.  Concomitant medications were not provided by the reporter.  Company Comment: Based on the current available information and temporal association between the use of the product and the start date of events, a causal relationship cannot be excluded. Follow-up information regarding pregnancy outcome has been requested.; Sender's Comments: Based on the current available information and temporal association between the use of the product and the start date of events, a causal relationship cannot be excluded. Follow-up information regarding pregnancy outcome has been requested.