Foetal exposure during pregnancy; Preterm birth at 34 weeks of gestation; Low birth weight of 2381 g; This is an observational study case, initially received from other health professional on 14-Jul-2020, concerning a male neonate, whose mother was a 40-year-old, pregnant, female subject of body weight: 172,5 lbs, height: 66.5 inches and body mass index (BMI): 27.4, enrolled in a prospective observational safety study.  The neonate's mother relevant medical history included body mass index increased and advanced maternal age.  The neonate's mother concomitant medications included Prenate Pixie- 10 mg Iron-1 mg-200 mg for pregnancy and vitamin D3 as health supplement.  The neonate's mother obstetrical history included three previous pregnancies with one elective abortion and two full term live births. The neonate's mother had no history of offspring with major congenital malformation (MCM) and no relevant maternal and paternal medical history. The neonate's mother did not use tobacco, alcohol or illicit drugs during pregnancy. The neonate's father was 41-year-old.   The neonate's mother last menstrual period (LMP) date was 29-Oct-2019. The estimated delivery date (EDD) and corrected estimated date of delivery (CEDD) were both reported as 04-Aug-2020. The type of pregnancy was multiple.   On 20-Dec-2019, at approximately 7 weeks of gestation (calculated per LMP), the neonate's mother was administered Afluria QIV (Flu Vaccine Egg Split QIV CSL) [influenza vaccine, batch number: P100126099, dose, route of administration, anatomical location and expiration date: not reported] (explicitly coded as 'Foetal exposure during pregnancy') for influenza immunization.  On the same day and on 03-Jan-2020, 18-Feb-2020, 17-Mar-2020 and 14-Apr-2020 the neonate's mother underwent ultrasound scan and no MCM was noted.   At gestational age of 34 weeks (as reported) the neonate's mother vaginally delivered preterm birth female-male twins (1 and 2). The neonate's 1 birth weight was 2149 g, head circumference 31 cm and body length 48 cm. The appearance, pulse, grimace, activity and respiration (APGAR) scores were 8 at one minute and 9 at five minutes. APGAR score was not reported for 10 minutes. The neonate's 2 birth weight was 2381 grams; head circumference 33 cm and body length 48 cm. The appearance, pulse, grimace, activity and respiration (APGAR) scores were 7 at one minute and 9 at five minutes. APGAR score was not reported for 10 minutes. There was no MCM identified at birth for twins.  At the time of initial reporting, the outcome of the events 'low birth weight baby' and 'premature baby 33 to 36 weeks' was not reported.   The events 'low birth weight baby' and 'premature baby 33 to 36 weeks' were assessed as serious due to the criteria of medical significance, per company.   The reporter did not provide causality assessment.  This case is linked to case 202003881 (the corresponding twin 1 case) and 202003880 (the corresponding mother case).  Company Comment: A 40-year-old pregnant subject was administered Afluria QIV at gestational age of 7 weeks. A male foetus experienced premature birth with low birth weight, six months after foetal exposure to the suspect product, Afluria QIV. Chronology is unsuggestive. Early-onset labour is frequent in twin pregnancies, which confound causality for low birth weight as well. Subject's medical history of body mass index increased and advanced maternal age may have contributed to development of the events as well. Therefore, causal role of the suspect vaccine is assessed as not related for premature birth and low birth weight. Foetal exposure during pregnancy is assessed as unrelated per company's conventions.; Sender's Comments: A 40-year-old pregnant subject was administered Afluria QIV at gestational age of 7 weeks. A male foetus experienced premature birth with low birth weight, six months after foetal exposure to the suspect product, Afluria QIV. Chronology is unsuggestive. Early-onset labour is frequent in twin pregnancies, which confound causality for low birth weight as well. Subject's medical history of body mass index increased and advanced maternal age may have contributed to development of the events as well. Therefore, causal role of the suspect vaccine is assessed as not related for premature birth and low birth weight. Foetal exposure during pregnancy is assessed as unrelated per company's conventions.