Foetal exposure during pregnancy; Fluid around kidneys; This is an observational study case, initially received from other health professional on 25-Aug-2020, concerning a male, neonate whose mother was a female, pregnant subject of body weight: 127 lbs, height: 60 inches and body mass index (BMI): 24.8, enrolled in a prospective observational safety study.   The neonate's mother medical history included migraines.  The neonate's mother concomitant medications were not provided.  The neonate's mother obstetrical history included one previous pregnancy with one full term live birth. The mother had no history of offspring with major congenital malformation (MCM). The mother had no maternal or paternal medical history with MCM. The neonate's mother did not use tobacco, alcohol or illicit drugs during pregnancy.  The neonate's mother last menstrual period (LMP) date was 24-May-2019. The neonate's mother estimated delivery date (EDD) and corrected estimated date of delivery (CEDD) both were reported as 28-Feb-2020. The type of pregnancy was singleton.   On 05-Sep-2019, the neonate's mother underwent panorama, cystic fibrosis mutation and spinal muscular atrophy test, and no MCM was noted.  On 12-Sep-2019 and 10-Oct-2019, the subject underwent ultrasound and no MCM was noted.  On 01-Nov-2019, at approximately 23 weeks of gestation (calculated per LMP), the neonate's mother was administered Flucelvax QIVc (Flu Vaccine Cell Subunit QIV NVD) [influenza vaccine, subunit influenza virus vaccine polyvalent; dose: 0.5 mL, batch number: 261218, route of administration, anatomical location and expiration date: not reported] (explicitly coded as 'Vaccine exposure during pregnancy') for an influenza immunisation.  On 19-Nov-2019, 04-Dec-2019, 02-Jan-2020, 10-Jan-2020 and 28-Jan-2020, the neonate's mother underwent ultrasound scans and no MCM was noted.  On 05-Feb-2020, three months and four days after vaccination, the neonate's mother developed anaemia and started treatment with ferrous sulfate at dose of 325 mg, twice a day, orally.  At 38.9 weeks of gestation (as reported), the mother delivered a live birth male neonate, via vaginal method of delivery. The neonate's birth weight was 3459 grams, while head circumference and body length were not reported. The appearance, pulse, grimace, activity and respiration (APGAR) scores at one, five and ten minutes were not reported.   On the same day, the baby had fluid around kidneys, which was noted as pregnancy complication at delivery. The doctors believed it would resolve on its own and a follow up with paediatrician would be done at 18 months.   At the time of this report, the neonate did not recover from the event of edematous kidney'.   The event of edematous kidney' was considered serious due to the criterion of medical significance, per company.    The reporter did not provide causality assessment to Flucelvax QIVc.  This case is linked to 202003945, the corresponding mother case.  Company comment: A pregnant subject was administered Flucelvax QIV at approximately 23 weeks of gestation. The subject delivered a live birth male neonate, via vaginal method of delivery. On the same day, 3 months 19 days after vaccination, it was noted that baby has fluid around kidneys. Chronology is unsuggestive. Causality is assessed as not related, due to biological/pharmacological implausibility. Foetal exposure during pregnancy assessed as not related per company's conventions.; Sender's Comments: A pregnant subject was administered Flucelvax QIV at approximately 23 weeks of gestation. The subject delivered a live birth male neonate, via vaginal method of delivery. On the same day, 3 months 19 days after vaccination, it was noted that baby has fluid around kidneys. Chronology is unsuggestive. Causality is assessed as not related, due to biological/pharmacological implausibility. Foetal exposure during pregnancy assessed as not related per company's conventions.