Breech delivery Baby B; Pregnant patient received both doses of moderna vaccine. Patient is expecting twins.; First dose: Jan 6 Second dose: Jan 31 2021; This spontaneous prospective pregnancy case was reported by a health care professional and describes the occurrence of BREECH DELIVERY (Breech delivery Baby B) in a 35-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 011L20A and 031L20A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Penicillin allergy, Sulfonamide allergy (Sulfa) and Smoker. Concomitant products included ACETYLSALICYLIC ACID (BABY ASPIRIN) and VITAMINS NOS for an unknown indication.   On 06-Jan-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 31-Jan-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. The patient's last menstrual period was on 20-Jul-2020 and the estimated date of delivery was 19-Apr-2021. On 06-Jan-2021, the patient experienced INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (First dose: Jan 6 Second dose: Jan 31 2021). On 31-Jan-2021, the patient experienced EXPOSURE DURING PREGNANCY (Pregnant patient received both doses of moderna vaccine. Patient is expecting twins.). On 01-Apr-2021, the patient experienced BREECH DELIVERY (Breech delivery Baby B) (seriousness criterion medically significant). The patient received mRNA-1273 (Moderna COVID-19 Vaccine) beginning around the  twenty-fourth week of the pregnancy. The patient gave birth to 2 neonates. The vaginal delivery occurred on 01-Apr-2021, which was reported as Full-term. For neonate 1, the birth weight was 3300 grams (7lbs 4oz). The outcome was reported as Term Birth w/o Complications. Mono-di-twins sex: male, lenght 50.8 cm, head cirumference 33 cm. For neonate 2, the birth weight was 3600 grams (7lbs 15oz). The outcome was reported as Term Birth w/o Complications. Breech delivery; Mono-di-twins sex: male, lenght 50.8 cm, head cirumference 31.8 cm. On 31-Jan-2021, EXPOSURE DURING PREGNANCY (Pregnant patient received both doses of moderna vaccine. Patient is expecting twins.) and INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (First dose: Jan 6 Second dose: Jan 31 2021) had resolved. On 01-Apr-2021, BREECH DELIVERY (Breech delivery Baby B) had resolved.        The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown) and 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.   On 24-Aug-2020, the patient received a positive pregnancy test result.  The patient received weekly ultrasounds and fetal non-stress test (NST).  On an unknown date the patient began oral prenatal vitamins, which she was continuing at the time of the pregnancy outcome report. Neonate-1 APGAR score #1 and 2: to unknown Neonate-2 APGAR score #1 and 2: to unknown  This is a case of product exposure during pregnancy with an associated adverse event of breech delivery in one of the newborn (gemelar pregnancy). Based on temporal association a causal relationship cannot be excluded.   Most recent FOLLOW-UP information incorporated above includes: On 14-Jul-2021: No new information. On 14-Jul-2021: Pregnancy outcome form completed.; Sender's Comments: This is a case of product exposure during pregnancy with an associated adverse event of breech delivery in one of the newborn (gemelar pregnancy). Based on temporal association a causal relationship cannot be excluded.