Premature delivery; Vaccine exposure during pregnancy; This is an observational study case, initially received on 16-Jan-2020, concerning a 36-year-old, pregnant female subject, of body weight 234 lbs, height 64 inches and body mass index (BMI) 40.2, enrolled in a prospective observational safety study.   The subject's current medical conditions included migraine, increased BMI and advanced maternal age.   The subject's concomitant medication included CitraNatal 90 DHA (vitamin C, calcium, iron, vitamin D3, vitamin E, thiamin, riboflavin, niacinamide, vitamin B6, folic acid, iodine, zinc, copper, docusate sodium, docosahexaenoic acid) as obstetrical (OB) vitamin.  The subject's obstetrical history noted that the subject had two previous pregnancies which included two full-term live births with no birth defects. The subject had no history of offspring with major congenital malformation (MCM). Also, the subject had no maternal or paternal history with MCM. The subject did not use tobacco, alcohol or illicit drugs during pregnancy.   The subject's last menstrual period (LMP) date was 10-Apr-2019, estimated delivery date (EDD) was reported as 15-Feb-2020, while corrected estimated date of delivery (CEDD) was reported as 03-Feb-2020. The type of pregnancy was singleton.   On 29-Jul-2019, the subject underwent Maternit 21 and no MCMs were noted.  On 22-Aug-2019, the subject underwent second trimester screen and alfa-fetoprotein screening (AFP). No MCMs were noted.  On 13-Sep-2019, at gestational age of 22 weeks, the subject was administered Flucelvax QIV (Flu Vaccine Cell Subunit QIV NVD) [influenza vaccine, subunit influenza virus vaccine polyvalent, dose: 0.5 mL, batch number: 26100, route of administration, anatomical location and expiration date: not reported] (explicitly coded as 'Vaccine exposure during pregnancy') for an influenza immunisation.   On the same day, the subject underwent anatomy scan and no MCMs were noted.  At gestational age of 36.6 weeks, the subject gave vaginally live birth to a male neonate. The neonate's birth weight, head circumference and length were not reported. The appearance, pulse, grimace, activity, and respiration (APGAR) scores were 8 at one minute and 9 at five minutes. APGAR score at 10 minutes was not provided. There were no MCM identified at birth.  At the time of this report, the outcome for the event of premature delivery was not reported.  Per company, the event of premature delivery was considered as serious due to criterion of medical significance.  The reporter did not provide causality assessment.  The case is linked to the case 202000171 (corresponding child case).  Company comment: Reportedly, premature delivery was associated with Flucelvax QIVc. Vaccine was administered at 22 weeks of gestation. Chronology is plausible. Causality was confounded by patient's advanced age. However, causal role of the suspect vaccine cannot be totally excluded and is assessed as unlikely related. Vaccine exposure during pregnancy is assessed as unrelated per company's conventions.; Sender's Comments: Reportedly, premature delivery was associated with Flucelvax QIVc. Vaccine was administered at 22 weeks of gestation. Chronology is plausible. Causality was confounded by patient's advanced age. However, causal role of the suspect vaccine cannot be totally excluded and is assessed as unlikely related. Vaccine exposure during pregnancy is assessed as unrelated per company's conventions.