Foetal exposure during pregnancy; Preterm birth at gestational age of 36.7 weeks; This is an observational study case, initially received from other health professional on 14-May-2020, concerning a male neonate whose mother was 30-year-old, female pregnant subject, of body weight: 173.5 lbs, height: 67 inches and body mass index (BMI): 27.2, enrolled in, a prospective observational safety study on pregnancy outcomes in women immunized with Afluria QIV, a seasonal quadrivalent vaccine, during pregnancy.  The subject's mother's medical history included high body mass index and uterine leiomyoma.   The subject's mother's concomitant medications included Prenatal gummy (unspecified vitamins and minerals) for pregnancy and Vitamin C (ascorbic acid) as supplement.  The subject's mother had no previous pregnancies. The subject's mother had no history of offspring with major congenital malformation (MCM). The subject's mother had no relevant maternal and paternal medical history. The subject's mother did not use tobacco, illicit drug or alcohol during pregnancy. The subject's father was 34-year-old.  The subject's mother's last menstrual period (LMP) date was reported as 16-Jun-2019. The type of pregnancy was singleton. The subject's mother's estimated delivery date (EDD) was reported as 23-Mar-2020 and corrected estimated date of delivery (CEDD) was reported as 22-Mar-2020.  On 12-Sep-2019, the subject's mother underwent ultrasound scan, no MCM was noted.  On 26-Sep-2019, at approximately 14 weeks of gestation (calculated per LMP), the subject's mother was administered Afluria QIV (Flu Vaccine Egg Split QIV CSL) [Influenza vaccine, subunit influenza virus vaccine polyvalent; batch number: P100118566, dose, anatomical location, route of administration and expiration date: not reported] (explicitly coded as Foetal exposure during pregnancy') for influenza immunisation.   On 01-Nov-2019, the subject's mother underwent ultrasound scan, no MCM was noted.  On, at gestational age of 36.7 weeks (as reported), the subject's mother delivered live birth, male neonate via vaginal method of delivery. The neonate's birth weight was 3118 grams, her head circumference: not reported, length: 45.7 cm and APGAR (appearance, pulse, grimace, activity and respiration) scores were at one minute, five minutes and ten minutes: not reported. There was no MCM identified at birth.  At the time of this report, the outcome of the event premature birth' was not reported.  The event of premature birth' was assessed as serious due to criterion of medical significance, per company.   The reporter did not provide causality assessment.  The case is linked to the case 202003407 (mother case).  Company Comment: A male neonate subject experienced preterm birth at gestational age of 36.7 weeks, five months after foetal exposure to Afluria QIV. The subject's mother was administered vaccine at gestational age of 14 weeks. The subject's mother's medical history included BMI high and uterine leiomyoma which may provide alterative aetiology for the event. Causal relationship is assessed as not related because of biological implausibility and unsuggestive chronology. Foetal exposure during pregnancy assessed as unrelated per company's conventions.; Sender's Comments: A male neonate subject experienced preterm birth at gestational age of 36.7 weeks, five months after foetal exposure to Afluria QIV. The subject's mother was administered vaccine at gestational age of 14 weeks. The subject's mother's medical history included BMI high and uterine leiomyoma which may provide alterative aetiology for the event. Causal relationship is assessed as not related because of biological implausibility and unsuggestive chronology. Foetal exposure during pregnancy assessed as unrelated per company's conventions.