Dysmature placenta; Anemia; Vaccine exposure during pregnancy; This is an observational study case initially received on 03-Apr-2020, concerning a 23-year-old female pregnant subject of body weight 185 lbs, height 63 inches and body mass index (BMI) 32.8, enrolled in a prospective observational safety study.   The subject's medical history included increased BMI and herpes simplex virus (HSV).  The subject's concomitant medication included Prenatal vitamins (unspecified vitamins and minerals) for pregnancy.  The subject's obstetrical history noted that the subject had one previous pregnancy of full term live birth 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 on 22-May-2019. The subject's estimated date of delivery (EDD) and corrected estimated date of delivery (CEDD) were both reported as 26-Feb-2020. The type of pregnancy was singleton.  On 23-Aug-2019, the subject underwent panorama test and no MCMs were noted.  On 11-Sep-2019, the subject underwent ultrasound and no MCMs were noted.  On 10-Oct-2019, at approximately 20 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 expiration date: not reported] (explicitly coded as 'Vaccine exposure during pregnancy') for an influenza immunisation.   On 11-Dec-2019, the subject underwent ultrasound and no MCMs were noted.  On 04-Jan-2020, the subject developed anaemia and started treatment with ferrous sulphate at the dose of 325 mg, used once a day, orally.  On 09-Jan-2020, the subject underwent ultrasound and no MCMs were noted. Also, the subject developed dysmature placenta, reported as pregnancy complication.  On 29-Jan-2020, the subject underwent ultrasound and no MCMs were noted.  At approximately 39.1 weeks of gestation (as reported), the subject gave live birth to a male neonate vaginally. The characteristics of the neonate included birth weight: 3054 grams, head circumference: 35 cm and length: 50.8 cm. The appearance, pulse, grimace, activity, and respiration (APGAR) scores were 8 at one minute and 9 at five minutes. No data was provided for APGAR score at 10 minutes. No MCMs were identified at the time of birth.   On the same day, the subject recovered from the event of dysmature placenta and anaemia, and treatment with ferrous sulphate was discontinued.  Per company, the event of placental disorder' was considered as serious due to criterion of medical significance.  The reporter did not provide causality assessment to Flucelvax QIV.  Company comment: A pregnant subject experienced anaemia and dysmature placenta, 2 months after receiving Flucelvax QIV. Chronology is compatible. The subject's medical history included increased BMI and herpes simplex virus (HSV). Anaemia is common during pregnancy. However, causal role of the suspect vaccine cannot be excluded and is assessed as unlikely related for both events (defaults to "related" in the safety database for reporting purposes). Vaccine exposure during pregnancy assessed as not related per company's conventions.; Sender's Comments: A pregnant subject experienced anaemia and dysmature placenta, 2 months after receiving Flucelvax QIV. Chronology is compatible. The subject's medical history included increased BMI and herpes simplex virus (HSV). Anaemia is common during pregnancy. However, causal role of the suspect vaccine cannot be excluded and is assessed as unlikely related for both events (defaults to "related" in the safety database for reporting purposes). Vaccine exposure during pregnancy assessed as not related per company's conventions.