Vaccine fetal exposure during pregnancy; Preterm birth at 35.7 weeks of gestational age; This observational study case was received from other health professional on 09-Mar-2021 and concerned a male neonate, whose mother was a 32-year-old, pregnant, female subject of body weight 129 lbs, height 58 inches and body mass index (BMI) 27, enrolled in, a prospective observational safety study on pregnancy outcome in women immunized with Afluria QIV, a seasonal quadrivalent vaccine, during pregnancy.  Maternal concurrent conditions included high BMI. Maternal concomitant medication included Vitafol one (ascorbic acid, betacarotene, colecalciferol, cupric oxide, cyanocobalamin, folic acid, magnesium oxide, nicotinamide, omega-3 fatty acids, polysaccharide-iron complex, potassium iodide, pyridoxine hydrochloride, riboflavin, thiamine mononitrate, tocopheryl acetate, zinc oxide) used for healthy pregnancy.  Maternal obstetrical history included two previous pregnancies with two full term live births. The neonate's mother had no offspring with major congenital malformations (MCMs). The neonate's mother had no maternal or paternal history with MCMs. The neonate's mother did not use tobacco, alcohol or illicit drugs during pregnancy.  The neonate's mother's last menstrual period (LMP) date was 20-Jun-2020, the estimated delivery date (EDD) was  reported as 27-Mar-2021 and corrected estimated date of delivery (CEDD) was not reported. The type of pregnancy was multiple. The neonate's father's age was not reported.  On 02-Sep-2020, at approximately 10 weeks of gestation (calculated per LMP), the neonate's mother was vaccinated with Afluria QIV (Flu Vaccine Egg Split QIV CSL) (influenza vaccine; dose, anatomical location and  route of administration: not reported] (explicitly coded as 'Foetal exposure during pregnancy') for influenza immunisation. The batch number was P100239705.  On 16-Sep-2020, the first trimester screen and panorama test revealed no MCMs.  On 19-Oct-2020, the second trimester screen revealed increased risk of Down syndrome. No MCMs were noted.  On 23-Oct-2020, follow up amniocentesis regarding increased risk of Down syndrome revealed normal result. No MCMs were noted.  At 35.7 weeks of gestation (as reported), the mother delivered two premature live male neonates by caesarean method. The characteristics of the second neonate included: birth weight 3056 g, head circumference: 35 cm, length: 48.3 cm. APGAR (appearance, pulse, grimace, activity and respiration) scores at one minute was seven, at five minutes was nine and at ten minutes were not reported. No MCM was identified at birth.  The outcome of the event of 'premature baby 33 to 36 weeks' was not reported.  The reporter did not provide a causality assessment.  The event of 'premature baby 33 to 36 weeks' was considered to be medically significant by a Physician within Seqirus's Pharmacovigilance and Risk Management Department.  This case is linked to cases 202007471 (the corresponding mother case) and 202102001 (the corresponding baby brother case).  Company comment:The neonate was born as premature baby 5 months and 23 days after foetal exposure to the suspect product, Afluria QIV. Chronology is implausible. The neonate's mother medical history of high body mass index and underlying twin pregnancy confounds causality for the event. Causality between the suspect product and the event premature baby is assessed as not related due to biological and chronological implausibility and presented confounders. Foetal exposure during pregnancy is assessed as not related per company's conventions.; Sender's Comments: The neonate was born as premature baby 5 months and 23 days after foetal exposure to the suspect product, Afluria QIV. Chronology is implausible. The neonate's mother medical history of high body mass index and underlying twin pregnancy confounds causality for the event. Causality between the suspect product and the event premature baby is assessed as not related due to biological and chronological implausibility and presented confounders. Foetal exposure during pregnancy is assessed as not related per company's conventions.