This case was initially received via an unknown source (no reference has been entered for a health authority or license partner) on 26-Jul-2021. The most recent information was received on 18-May-2022 and was forwarded to Moderna on 18-May-2022. This spontaneous prospective pregnancy case was reported by an other health care professional and describes the occurrence of PRODUCT DOSE OMISSION ISSUE (First dose around the 21MAY2021 and was hesitant to receive the second dose) and MATERNAL EXPOSURE DURING PREGNANCY (Patient received the first dose of the vaccine and found out she was pregnant) in a 19-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. Concomitant products included MINERALS NOS, VITAMINS NOS (PRENATAL VITAMINS [MINERALS NOS; VITAMINS NOS]) for an unknown indication. On 21-May-2021, 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 21-May-2021, the patient experienced MATERNAL EXPOSURE DURING PREGNANCY (Patient received the first dose of the vaccine and found out she was pregnant). On an unknown date, the patient experienced PRODUCT DOSE OMISSION ISSUE (First dose around the 21MAY2021 and was hesitant to receive the second dose). The delivery occurred on an unknown date, which was reported as Normal Pregnancy Outcome. For neonate 1, The outcome was reported as Delivered NOS. Delivered a healthy baby boy. On 21-May-2021, MATERNAL EXPOSURE DURING PREGNANCY (Patient received the first dose of the vaccine and found out she was pregnant) had resolved. At the time of the report, PRODUCT DOSE OMISSION ISSUE (First dose around the 21MAY2021 and was hesitant to receive the second dose) outcome was unknown. The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was unknown. For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter did not provide any causality assessments. No treatment medication reported. Estimated Due Date was provided as February 2022. Reporter stated that the patient found out she was pregnant the last couple of weeks at the time of report and did not complain of any adverse events. Company comment: This spontaneous case reported by a Health care professional, concerns a 19 year old female patient with no medical history reported, who experienced the unexpected, non-serious events of Maternal exposure during pregnancy (Patient received the first dose of the vaccine and found out she was pregnant) on the same day after receiving the first dose of mRNA1273 vaccine. Reporter stated that the patient found out she was pregnant the last couple of weeks at the time of report and did not complain of any adverse events. On an unknown date she had PRODUCT DOSE OMISSION ISSUE (First dose around the 21MAY2021 and was hesitant to receive the second dose). Estimated Due Date was provided as February 2022.  It was reported that the delivery occurred on an unknown date, which was reported as Normal Pregnancy Outcome, Delivered a healthy baby boy. The event had resolved. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report. Event seriousness assessed as per medical judgement. This case was linked to MOD-2021-114442 (Patient Link). Most recent FOLLOW-UP information incorporated above includes: On 18-May-2022: Significant follow up received on 18-May-2022: Pregnancy outcome updated. Sender's Comments: This spontaneous case reported by a Health care professional, concerns a 19 year old female patient with no medical history reported, who experienced the unexpected, non-serious events of Maternal exposure during pregnancy (Patient received the first dose of the vaccine and found out she was pregnant) on the same day after receiving the first dose of mRNA1273 vaccine. Reporter stated that the patient found out she was pregnant the last couple of weeks at the time of report and did not complain of any adverse events. On an unknown date she had PRODUCT DOSE OMISSION ISSUE (First dose around the 21MAY2021 and was hesitant to receive the second dose). Estimated Due Date was provided as February 2022. It was reported that the delivery occurred on an unknown date, which was reported as Normal Pregnancy Outcome, Delivered a healthy baby boy. The event had resolved. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report. Event seriousness assessed as per medical judgement.