Birth weight 4451 grams/Large for gestational age; Anemia; Vaccine exposure during pregnancy; This is a serious observational study case, initially received on 30-May-2019, concerning a 21-year-old adult female pregnant subject of body weight: 127.4 lbs, height 64 inches and body mass index (BMI): 21.9, enrolled in a prospective observational safety study on pregnancy outcomes in women immunized with Afluria QIV, a seasonal quadrivalent vaccine, during pregnancy.  The subject had no previous pregnancies. The subject did not have any history of offspring with major congenital malformation. Also, the subject had no maternal or paternal history with major congenital malformations. The subject did not have prior history of use of tobacco, alcohol or illicit drugs during pregnancy. The pregnancy status of the subject was collected, and no pregnancy complications were noted.  The subject's current conditions included Anti-D screening positive and Rh D negative. The subject's concomitant medications included Rhogam (anti-D Immunoglobulin) for Anti-D screening Positive, prenatal vitamins (minerals Nos; vitamins Nos) as a supplement.  The subject's last menstrual period (LMP) date was 28-Aug-2018. The type of pregnancy was singleton.  On 07-Nov-2018, at gestational age of approximately 10-weeks (first trimester of pregnancy), the subject was administered Flu Vaccine Egg Split QIV CSL (influenza vaccine, batch number: YF42609, 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, the subject underwent ultrasound test, and no major congenital malformation was noted.  On 26-Dec-2018, the subject prenatal tests which included sequential 2 test and inheritest core test were performed, and no major congenital malformation was noted.  On 07-Jan-2019, 2 months after administration of study vaccine, the subject experienced anaemia and was treated with iron (dose: 325 mg, frequency: QD, route: oral, start date: 07-Jan-2019 which was continued).  The subject's corrected estimated delivery date (CEDD) was reported as 02-Jun-2019 and estimated delivery date (EDD) was reported as 04-Jun-2019.  On gestation age of 41 weeks, the subject gave a live birth to a normal male neonate by vacuum assisted vaginal delivery method. The characteristics of the neonate included birth weight: 4451 grams (explicitly coded as large at gestational age), head circumference: no data, body length: no data and appearance, pulse, grimace, activity, and respiration (APGAR) scores were 8 at one minute, 9 at five minutes and no data for ten minutes). There were no major congenital malformations identified at birth.  The subject had not yet recovered from the event anaemia.   This case is linked to 201903911 (baby case).   Follow up received from other health professional on 18-Jun-2019: The pregnancy outcome details included delivery method: vacuum assisted vaginal delivery method, foetal outcome: normal, birth type: live birth, infant's gender (male), birth weight (4451 grams), APGAR score (8 at one minute and 9 at five minute) were updated in patient tab. The new serious event large for gestational age' was added in the event tab. It was reported that, there were no major congenital malformations identified at birth. The narrative was amended accordingly.; Reporter's Comments: A 21-year-old pregnant subject experienced anaemia, 2 months after administration of Flu Vaccine Egg Split QIV CSL (vaccine exposure during pregnancy). The company assessed the causality of the event anaemia as not related to the suspect vaccine Due to implausible temporal relationship, underlying pregnancy condition and no evidence for a biological mechanism that could cause the event, hence the company assessed the causality of the event anaemia was assessed as not related to the suspect vaccine. The decision to administer a vaccine during pregnancy is related to medical decision making by the mother and her physician and is not related to any property of the medication. The event of vaccine exposure during pregnancy was assessed as not related considering the intended use of the vaccine.  The event large for gestational age assessed as not related to suspect vaccine due to no known biological mechanism.