Preterm delivery at 36.1 weeks of gestation; Vaccine exposure during pregnancy; This is an observational study case, initially received from other health professional on 09-Jun-2020, concerning a 34-year-old, pregnant female subject (Race: Ethnicity: not reported) of body weight: 146 lbs, height: 71 inches and body mass index (BMI): 20.4, enrolled in a prospective observational study on pregnancy outcomes in women immunized with Flucelvax, seasonal cell culture influenza trivalent (TIVc) or quadrivalent (QIVc) vaccine during pregnancy.  The subject's medical history included history of migraines.     The subject's concomitant medication included Prenatal vitamin (unspecified vitamins and minerals) for pregnancy.   The subject's obstetrical history included three previous pregnancies with two full term live births and one spontaneous abortion. The subject did not have a history of offspring with major congenital malformation (MCM). Also, the subject had no maternal or paternal history with MCMs.   The subject's last menstrual period (LMP) date was 22-Aug-2019, the estimated delivery date (EDD) and corrected estimated date of delivery (CEDD) were reported as 28-May-2020. The type of pregnancy was singleton. The subject did not use tobacco, alcohol or illicit drugs during pregnancy.  On 16-Sep-2019, the subject underwent cystic fibrosis mutation analysis and spinal muscular atrophy test and no MCM was noted.  On 24-Sep-2019 and 04-Oct-2019, the subject underwent ultrasound scan and no MCM was noted.   On 23-Oct-2019, at approximately eight weeks of gestation (calculated per LMP), 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: 261218, route of administration, anatomical location and expiry date: not reported] (explicitly coded as Vaccine exposure during pregnancy') for influenza immunisation.   On the same date, the subject underwent panorama test and ultrasound scan, no MCM was noted.   On 18-Nov-2019, 10-Apr-2020 and 23-Apr-2020, the subject underwent ultrasound scan and no MCM was noted.   At 36.1 weeks of gestation (as reported), the subject delivered a live birth female neonate, by vaginal method of delivery. The neonate's birth weight was 3368 grams, head circumference was 35.6 cm and body length 48.3 cm. The appearance, pulse, grimace, activity, and respiration (APGAR) scores were 8 at one minute and 9 at five minutes. APGAR score was not reported for 10 minutes. There was no major congenital malformation identified at birth.   At the time of this report, the outcome of event premature delivery' was not reported.   The event of premature delivery' was assessed as serious due to the criterion of medical significance, per company.   The reporter did not provide causality assessment.  This case is linked to 202003780 (corresponding baby case).  Company comment: A pregnant subject experienced premature delivery, six months after receiving Flucelvax QIV. Vaccine was administered at gestational age of eight weeks. Chronology is unsuggestive. The subject's medical history included history of migraines. Causal role of the suspect vaccine is assessed as not related. Vaccine exposure during pregnancy assessed as not related per company's conventions.; Sender's Comments: A pregnant subject experienced premature delivery, six months after receiving Flucelvax QIV. Vaccine was administered at gestational age of eight weeks. Chronology is unsuggestive. The subject's medical history included history of migraines. Causal role of the suspect vaccine is assessed as not related. Vaccine exposure during pregnancy assessed as not related per company's conventions.