Neonate's birth weight was 4196 grams/large for gestational age; Vaccine exposure during pregnancy; This is a serious observational study case, initially received on 31-May-2019 and follow-up received on 04-Jun-2019 (being processed together), concerning a 25-year-old adult, female (pregnant subject of body weight: 189 lbs, height: 68 inches and body mass index (BMI): 28.7, enrolled prospective observational safety study on pregnancy outcomes in women immunized with seasonal cell culture influenza trivalent (TIVc) or quadrivalent (QIVc) vaccine during pregnancy.  The subject's maternal history included wildervanck syndrome of sister. The subject had one previous pregnancy with full term liver birth. The subject had no history of offspring with major congenital malformation. The subject had no paternal history with major congenital malformations. The subject did not have a prior history of use of tobacco, alcohol or illicit drugs during pregnancy. The subject's concomitant medications included Prenatal vitamins (minerals nos, vitamins nos) for pregnancy and Colace (docusate sodium) as stool softener.  The subject's last menstrual period (LMP) date was 19-Jun-2018. The type of pregnancy was singleton. The subject's pregnancy status was collected and there were no complications noted.  On 14-Aug-2018, the subject underwent spinal muscular atrophy screen and cystic fibrosis mutation analysis, the results were normal as no congenital malformations were noted.  On 11-Sep-2018, the subject underwent ultrasound scan and no congenital malformations were noted.  On 16-Oct-2018, at gestational age of approximately 17 weeks, the pregnant subject was administered Flu Vaccine Cell Subunit QIV NVD (influenza vaccine, subunit influenza virus vaccine polyvalent, batch number: 252664, dose, route of administration, expiry date and anatomical location: not reported) (explicitly coded as vaccine exposure during pregnancy) for an unknown indication.  On the same day (16-Oct-2018), the subject underwent ultrasound scan and no congenital malformations were noted.  On 25-Oct-2018, the subject underwent quad screen test (prenatal test), and no major congenital malformation was noted.  at gestational age of 40 weeks, the subject gave a live birth to a male neonate by vaginal method. The characteristics of the neonate included birth weight: 4196 grams (explicitly coded as large for gestational age), head circumference: 35.6 cm, body length: 56.4 cm, appearance, pulse, grimace, activity, and respiration (APGAR) scores at one minute: 8, five minutes: 9 and ten minutes: no data was provided. There were no major congenital malformations identified at birth.  The outcome of the event hard stools was not reported.  The subject's estimated delivery date (EDD) was reported as 26-Mar-2019.  This case is linked to case 201903686 (baby case).; Reporter's Comments: A 25-year-old pregnant subject delivered large for gestational age (LGA) baby at 40 weeks of gestation, diagnosed at birth after receipt of Flu Vaccine Cell Subunit QIV at 17 weeks of gestation (considered as vaccine exposure during pregnancy). The known aetiologies of LGA includes genetic, increased maternal weight gain during pregnancy and maternal gestational diabetes. Considering the lack of biological evidence associated with study vaccine, the event large for gestational age, causality assessed as not related. The maternal BMI 28.7 is considered as known risk factor. The event vaccine exposure during pregnancy assessed as not related considering the intended use of the vaccine.  The case will be further assessed upon receipt of follow-up information. The company assessed the case as serious (medically significant).