Foetal exposure during pregnancy; Birth weight 4026 g; This is an observational study case from the United States, initially received from other health professional on 17-Feb-2020, concerning a  male, neonate subject, whose mother was a 35-year-old female of body weight 143 lbs, height 64.8 inches and body mass index (BMI) 23.9, enrolled in a prospective observational safety study.  The mother's current conditions included advanced maternal age, mixed anxiety and depressive disorder, morning sickness/ nausea and low-lying placenta.   The subject's mother concomitant medications included ondansetron for nausea, fluoxetine for an unknown indication, Prozac (fluoxetine hydrochloride) for anxiety and depression, Diclegis (doxylamine succinate, pyridoxine hydrochloride) for morning sickness, unspecified vitamins as OB supplementation and Tdap (diphtheria vaccine toxoid, pertussis vaccine acellular, tetanus vaccine toxoid) as vaccine immunisation.    The mother had no previous pregnancies. The subject's mother had no paternal history with major congenital malformations (MCMs), but in maternal family history malignant neoplasm of uterus in mother and malignant breast tumour in grandmother were noted. The mother did not use tobacco, alcohol or illicit drugs during pregnancy.   The mother's last menstrual period (LMP) was on 19-Feb-2019 and type of pregnancy was singleton. The estimated delivery date (EDD) was reported as 26-Nov-2019 and corrected estimated date of delivery (CEDD) of subject's mother was reported as 06-Dec-2019. The subject's father was a 32-year-old.  On 15-May-2019, the subject's mother underwent MaterniT21 prenatal test and no MCM was noted.  On 19-Jun-2019, the subject's mother underwent second trimester screen and maternal serum alpha fetoprotein (MSAFP/serum markers) and no MCM was noted.  On 15-Jul-2019, the subject's mother underwent anatomy ultrasound and no MCM was noted.   On 18-Sep-2019, at approximately 28 weeks of gestation, the mother was administered Flucelvax QIV (Flu Vaccine Cell Subunit QIV NVD) [influenza vaccine, subunit influenza virus vaccine polyvalent, batch number: 261200, dose: 0.5 ml, route of administration, anatomical location and expiration date: not reported] (explicitly coded as Foetal exposure during pregnancy') for an influenza immunization.   On the same day, the subject's mother experienced gastroesophageal reflux disease (GERD) and was treated with ranitidine at 1 tablet, orally, every day.   At 39.4 weeks of gestation, the subject's mother delivered a normal, male neonate by caesarean method. The neonate's birth weight was 4026 grams, while head circumference and body length were not reported. The appearance, pulse, grimace, activity, and respiration (APGAR) scores were 8 (one minute) and 9 (five minutes). APGAR score was not reported for 10 minutes. There was no major congenital malformation identified at birth. Pregnancy complications included placenta previa antepartum in third trimester.  At the time of initial reporting, the outcome of the event birth weight excessive' was not reported.  The event of birth weight excessive' was considered serious due to the criterion of medical significance, per company.  The causality assessment was not provided.  This case is linked to 202001215 (the corresponding mother case).  Company Comment: A male neonate subject was delivered as large for dates baby after maternal receipt of Flucelvax QIV vaccine at approximately 28 weeks of gestation (considered as foetal exposure during pregnancy). Chronology seems plausible.  Mother's medical history advanced maternal age and mixed anxiety, depressive disorder and Tdap vaccine (diphtheria vaccine toxoid, pertussis vaccine acellular, tetanus vaccine toxoid) may have contributed to development of the event. Multiple concomitant medications may provide alternative aetiology for the event. Foetal exposure during pregnancy assessed as not related per company's conventions. Considering all the above mentioned, causality between suspect product and the event large for dates baby is assessed as unlikely related (defaults to "related" in the safety database for reporting purposes).; Sender's Comments: A male neonate subject was delivered as large for dates baby after maternal receipt of Flucelvax QIV vaccine at approximately 28 weeks of gestation (considered as foetal exposure during pregnancy). Chronology seems plausible.  Mother's medical history advanced maternal age and mixed anxiety, depressive disorder and Tdap vaccine (diphtheria vaccine toxoid, pertussis vaccine acellular, tetanus vaccine toxoid) may have contributed to development of the event. Multiple concomitant medications may provide alternative aetiology for the event. Foetal exposure during pregnancy assessed as not related per company's conventions. Considering all the above mentioned, causality between suspect product and the event large for dates baby is assessed as unlikely related (defaults to "related" in the safety database for reporting purposes).