Preterm birth at 30.3 weeks of gestation; Birth weight 1389 g; Foetal exposure during pregnancy; This is an observational study case initially received on 15-Apr-2020, concerning a 21-year-old female pregnant subject of body weight 178.6 lbs, height 64 inches and body mass index (BMI) 30.7, enrolled in a prospective observational safety study.  The subject's mother's current medical condition included increased BMI, nausea and Rhesus (Rh) antibodies (anti D) negative.   The subject's mother's concomitant medications included Flintstones gummies (unspecified vitamins) as vitamin, Diclegis (doxylamine succinate and pyridoxine hydrochloride) for nausea and TDAP (diptheria vaccine toxoid, pertussis vaccine acellular, tetanus vaccine toxoid) as vaccine.  The subject's mother's obstetrical history noted that the subject's mother had two previous pregnancies with one spontaneous abortion and one full term live birth by cesarean with no birth defects. The subject's mother had no history of offspring with major congenital malformation (MCM). Also, the subject' mother had no maternal or paternal history with MCM. The subject's mother did not use tobacco, alcohol or illicit drugs during pregnancy.   The subject's mother's last menstrual period (LMP) date was not reported. The subject's mother's estimated date of delivery (EDD) was not reported, while corrected estimated date of delivery (CEDD) was reported as 28-May-2020. The type of pregnancy was singleton. The subject's father's age was 32.  On 20-Oct-2019, the subject' mother underwent dating scan and no MCMs were noted.  On 29-Oct-2019, at unknown week of gestation, the subject's mother was administered Flucelvax QIVc (Flu Vaccine Cell Subunit QIV NVD) [influenza vaccine, subunit influenza virus vaccine polyvalent, dose: 0.5 mL, batch number reported as 2612233 (Seqirus batch number: 261223; 261233), route of administration, anatomical location and expiration date: not reported] (explicitly coded as Foetal exposure during pregnancy') for an influenza immunisation.   On 21-Nov-2019, 23 days after vaccination, the subject's mother developed bacterial vaginosis and started corrective treatment with metronidazole at the dose of one tablet, twice daily, orally. On the same day, the subject's mother underwent first trimester screen and no MCMs were noted.  On 19-Dec-2019, the subject's mother underwent maternal serum alpha fetoprotein screening (MSAFP) and second trimester screen. No MCMs were noted.  On 08-Jan-2020, the subject's mother underwent anatomy ultrasound and no MCMs were noted.  At 30.3 weeks of gestational age, the subject's mother vaginally delivered live female neonate. The delivery was precipitous. The characteristics of neonate included birth weight: 1389 grams, body length and head circumference were not reported. Appearance, pulse, grimace, activity, and respiration (APGAR) scores for one, five and ten minutes were not reported. It was unknown if MCMs were identified at the time of birth. The subject was put in the neonatal intensive care unit (NICU).  At the time of this report, the outcome for the events of premature baby' and 'low birth weight baby' were not reported.  The events of premature baby' and 'low birth weight baby' were assessed as serious due to the criterion of medically significance and hospitalization, per company.  The reporter did not provide causality assessment to Flucelvax QIVc.  This case is linked to 201907070 (corresponding mother case).  Company Comment: A neonate subject experienced premature birth and low birth weight 4 months and 21 days after foetal exposure to the suspect product Flucelvax QIVc. Mother was administered Flucelvax QIVc at unknown age of gestation. Chronology is unsuggestive. The subject's mother had two previous pregnancies with one spontaneous abortion and one full term live birth by cesarean with no birth defects. Causality was highly confounded by maternal Rhesus (Rh) antibodies (anti D) negative. It was not reported baby's blood group or whether RhoGam was given. Causal role of the suspect product is assessed as not related. Foetal exposure during pregnancy is assessed as not related per company conventions.; Sender's Comments: A neonate subject experienced premature birth and low birth weight 4 months and 21 days after foetal exposure to the suspect product Flucelvax QIVc. Mother was administered Flucelvax QIVc at unknown age of gestation. Chronology is unsuggestive. The subject's mother had two previous pregnancies with one spontaneous abortion and one full term live birth by cesarean with no birth defects. Causality was highly confounded by maternal Rhesus (Rh) antibodies (anti D) negative. It was not reported baby's blood group or whether RhoGam was given. Causal role of the suspect product is assessed as not related. Foetal exposure during pregnancy is assessed as not related per company conventions.