next day nausea went away; 4-weeks pregnant; miscarriage shortly thereafter; had pretty bad effects with the second dose: felt really terrible; This spontaneous retrospective pregnancy case was reported by a nurse and describes the occurrence of ABORTION SPONTANEOUS (miscarriage shortly thereafter) in a 35-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 024M20A and 027L20A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.   On 17-Jan-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 13-Feb-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. Last menstrual period and estimated date of delivery were not provided. On 13-Feb-2021, the patient experienced NAUSEA (next day nausea went away) and MATERNAL EXPOSURE DURING PREGNANCY (4-weeks pregnant). In February 2021, the patient experienced ABORTION SPONTANEOUS (miscarriage shortly thereafter) (seriousness criterion medically significant) and FEELING ABNORMAL (had pretty bad effects with the second dose: felt really terrible). The delivery occurred on an unknown date, which was reported as Spontaneous Abortion. For foetus 1, The outcome was reported as Spontaneous Abortion NOS. On 13-Feb-2021, MATERNAL EXPOSURE DURING PREGNANCY (4-weeks pregnant) had resolved. On 14-Feb-2021, NAUSEA (next day nausea went away) had resolved. At the time of the report, ABORTION SPONTANEOUS (miscarriage shortly thereafter) and FEELING ABNORMAL (had pretty bad effects with the second dose: felt really terrible) outcome was unknown.        For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments.   No medical history and treatment was provided. No concomitant medication was reported. Company Comment : This case concerns a 35-year-old, female patient with no relevant medical history reported, with Maternal exposure during pregnancy (during the first trimester, gestational age of 4 weeks), who experienced the unexpected serious event of abortion spontaneous and non- serious events nausea (expected) and feeling abnormal (unexpected). The event abortion spontaneous occurred at an unknown day (shorlty) after the second dose of mRNA-1273 vaccine. The rechallenge was not applicable for abortion spontaneous due to the nature of the event. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report. Case was assessed as serious due to important medical event and medical judgement.   This case was linked to MOD-2021-390096 (Patient Link).; Sender's Comments: This case concerns a 35-year-old, female patient with no relevant medical history reported, with Maternal exposure during pregnancy (during the first trimester, gestational age of 4 weeks), who experienced the unexpected serious event of abortion spontaneous and non- serious events nausea (expected) and feeling abnormal (unexpected). The event abortion spontaneous occurred at an unknown day (shorlty) after the second dose of mRNA-1273 vaccine. The rechallenge was not applicable for abortion spontaneous due to the nature of the event. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report. Case was assessed as serious due to important medical event and medical judgement.