Foetal exposure during pregnancy; Birth weight was 4065 g; This is an observational study case, initially received on 19-Jun-2020, concerning a female, neonate whose mother was 34-year-old pregnant, female subject of body weight 171 lbs, height 65 inches and body mass index (BMI) 28.5, enrolled in a prospective observational safety study.  The neonate's mother's current condition included increased BMI. The neonate's mother's historical condition included urinary tract infection.  The neonate's mother's concomitant medications included prenatal vitamins (unspecified minerals and vitamins) for pregnancy and Macrobid (clarithromycin) for urinary tract infection.  The neonate's mother's obstetrical history noted that the mother had two previous pregnancies of full-term live birth. No birth defects were noted. The neonate's mother had no history of offspring with major congenital malformation (MCM). Also, 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 28-May-2019, the estimated delivery date (EDD) was reported as 03-Mar-2020, while the corrected estimated date of delivery (CEDD) was not reported. The type of pregnancy was singleton.   On 23-Jul-2019, the neonate's mother underwent dating ultrasound. The results were normal and no MCM was noted.  On 30-Jul-2019, the neonate's mother underwent prenatal bloodwork. The results were normal and no MCM was noted.  On 06-Aug-2019, the neonate's mother underwent gonorrhoea and chlamydia culture test. The results were negative and no MCM was noted.  On 16-Aug-2019, the neonate's mother underwent first trimester screen. The results were normal and no MCM was noted.  On 16-Oct-2019, at approximately 20 weeks of gestation (calculated per LMP), the neonate's mother was administered Afluria QIV (Flu Vaccine Egg Split QIV CSL) [influenza vaccine; batch number: P100123038, dose, route of administration, anatomical location and expiration date: not reported] (explicitly coded as 'Foetal exposure during pregnancy') for an influenza immunisation.   On the same day, the neonate's mother underwent anatomic scan. The results were normal and no MCM was noted.  At approximately 39.9 weeks of gestation (as reported), the mother delivered a live female neonate via caesarean method. The neonate's birth weight was 4065 g, body length was 55.9 cm and head circumference was 35.6 cm. The appearance, pulse, grimace, activity, and respiration (APGAR) scores were 8 (one minute) and 9 (five minutes), while no data was provided for ten minutes. No MCMs were identified at the time of birth.   At the time of this report, the outcome of the event 'high birthweight baby' was not reported.  The event of 'high birthweight baby' was considered as serious due to criterion of medical significance, per company.  The reporter did not provide causality assessment.  This case is linked to the case 201905996, the corresponding mother case.  Company comment: Reportedly, large for dates baby was associated with Afluria QIV. A subject's mother was vaccinated at 20 weeks of gestation. The baby was born 4 months 15 days later. It was reported that birth weight was 4065 g, body length was 55.9 cm and head circumference was 35.6 cm. Causality was confounded by increased BMI in mother. Causal role of the suspect vaccine for the event large for dates baby is assessed as unrelated due to biological implausibility. Foetal exposure during pregnancy is assessed as unrelated per company's conventions.; Sender's Comments: Reportedly, large for dates baby was associated with Afluria QIV. A subject's mother was vaccinated at 20 weeks of gestation. The baby was born 4 months 15 days later. It was reported that birth weight was 4065 g, body length was 55.9 cm and head circumference was 35.6 cm. Causality was confounded by increased BMI in mother. Causal role of the suspect vaccine for the event large for dates baby is assessed as unrelated due to biological implausibility. Foetal exposure during pregnancy is assessed as unrelated per company's conventions.