Dysmature placenta; Gestational diabetes; Vaccine exposure during pregnancy; This is an observational study case, initially received from other health professional on 09-Jun-2020, concerning a 21-year-old, female pregnant subject of body weight: 197 lbs, height: 64 inches and body mass index (BMI): 33.8, enrolled in a prospective observational safety study on pregnancy outcomes in woman immunized with seasonal cell culture influenza trivalent (TIVc) or quadrivalent (QIVc) vaccine during pregnancy.  The subject's medical history included high BMI and asthma.  The subject's concomitant medications included Prenatal vitamins (unspecified vitamins and minerals) for pregnancy.   The subject's obstetrical history included one previous pregnancy with one spontaneous abortion. The subject had no history of offspring with major congenital malformation (MCM). The subject had no relevant maternal and paternal medical history with MCM. The subject did not use tobacco, illicit drug or alcohol during pregnancy.  The subject's last menstrual period (LMP) date was reported as 23-Jul-2019. The subject's estimated delivery date (EDD) and corrected estimated date of delivery (CEDD) both were reported as 28-Apr-2020. The type of pregnancy was singleton.   On 16-Sep-2019, the subject underwent ultrasound and no MCM was noted.  On 14-Oct-2019, at approximately 12 weeks of gestation (calculated per LMP), the subject was administered Flucelvax QIVc (Flu Vaccine Cell Subunit QIV NVD) [influenza vaccine, subunit influenza virus vaccine polyvalent; batch number: 261218, dose: 0.5 mL, 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 panorama test and no MCM was noted.  On 11-Nov-2019, the subject underwent ultrasound and no MCM was noted.  On 10-Jan-2020, two months and 27 days after vaccination, the subject developed gestational diabetes.  On 19-Feb-2020, four months and five days after vaccination, the subject developed dysmature placenta. On the same day, the subject underwent ultrasound and no MCM was noted.  On 25-Mar-2020 and 08-Apr-2020, the subject underwent ultrasound and no MCM was noted.  at gestational age of 39.3 weeks (as reported), the subject vaginally delivered live birth, female neonate. The neonate's birth weight was not reported, her length was 43.2 cm and head circumference was 30.5 cm. The appearance, pulse, grimace, activity, and respiration (APGAR) score was 8 at one minute, 9 at five minutes and for ten minutes was not provided. No MCM was identified at birth.   On the same day, the subject recovered from dysmature placenta and gestational diabetes.  The events of dysmature placenta and gestational diabetes were assessed as serious due to criterion of medical significance.  The reporter did not provide causality assessment to Flucelvax QIVc.  The case is linked to case 202003784 (the corresponding baby case).  Company comment: A pregnant subject experienced gestational diabetes three months after receiving Flucelvax QIV. The subject also developed placental disorder (dysmature placenta) four months after vaccination. The subject's medical history included high BMI and asthma. Causal role of the suspect vaccine is assessed as not related for both events, due to biological implausibility and unsuggestive chronology. Vaccine exposure during pregnancy assessed as not related per company's conventions.; Sender's Comments: A pregnant subject experienced gestational diabetes three months after receiving Flucelvax QIV. The subject also developed placental disorder (dysmature placenta) four months after vaccination. The subject's medical history included high BMI and asthma. Causal role of the suspect vaccine is assessed as not related for both events, due to biological implausibility and unsuggestive chronology. Vaccine exposure during pregnancy assessed as not related per company's conventions.