Dysmature placenta; Vaccine exposure during pregnancy; This is an observational study case, initially received from other health professional on 16-Mar-2020, concerning a 22-year-old, female pregnant subject of body weight 170 lbs, height 67 inches and body mass index (BMI) 26.6, enrolled in a prospective observational safety study.  The subject's current condition included high BMI.  The subject's concomitant medications included Prenatal vitamins (unspecified vitamins and minerals) for pregnancy.   The subject had no obstetrical history. The subject had no history of offspring with major congenital malformation (MCM) and no relevant maternal and paternal medical history with MCM. The subject did not use tobacco, alcohol or illicit drugs during pregnancy.   The subject's last menstrual period (LMP) date was 06-Apr-2019. The subject's estimated date of delivery (EDD) and corrected estimated date of delivery (CEDD) were reported as 11-Jan-2019. The type of pregnancy was singleton.  On 21-May-2019, the subject underwent prenatal tests cystic fibrosis mutation analysis, horizon 4 and spinal muscular atrophy screen and no MCM was noted.   On 20-Jun-2019, the subject underwent panorama test and no MCM was noted.   On 05-Aug-2019, the subject underwent maternal serum alpha fetoprotein (MSAFP) / serum markers screening and no MCM was noted.  On 08-Oct-2019, at gestational age of approximately 26 weeks (calculated per LMP), the subject was administered Flucelvax QIV (Flu Vaccine Cell Subunit QIV NVD) [influenza vaccine, subunit influenza virus vaccine polyvalent, batch number reported, dose: 0.5 ml, route of administration, anatomical location and expiration date: not reported] (explicitly coded as Vaccine exposure during pregnancy') for an influenza immunization.  On 20-Nov-2019, the subject underwent ultrasound and no MCM was noted.   On 26-Nov-2019 and 05-Dec-2019, the subject underwent non-stress test and no MCM was noted.  On 12-Dec-2019, the subject underwent ultrasound and no MCM was noted.  On 19-Dec-2019, the subject underwent non-stress test and no MCM was noted.  On unspecified date in 2019, the subject underwent ultrasound and no MCM was noted.  On unspecified date, the subject experienced dysmature placenta.    At gestational age of 39.6 weeks (as reported), the subject gave live birth to a male neonate vaginally. The neonate's birth weight was 2985 grams, head circumference 33.7 cm and body length 51.4 cm. The appearance, pulse, grimace, activity, and respiration (APGAR) scores were 9 at one minute and at five minutes. APGAR score was not reported for 10 minutes. There was no MCM identified at birth.   At the time of initial report, the outcome of the event of dysmature placenta was not reported.  The event of dysmature placenta was assessed as serious due to the criterion of medical significance, per company.  The reporter did not provide causality assessment.  Company comment: Reportedly, placental disorder (dysmature placenta) was associated with Flucelvax QIV. The patient was vaccinated at approximately 26 weeks of gestation and the event was noted on an unspecified date. Chronology needs more clarification. Due to lack of information, causal role of the suspect vaccine is unasseassable. Vaccine exposure during pregnancy is assessed as unrelated per company's conventions.; Sender's Comments: Reportedly, placental disorder (dysmature placenta) was associated with Flucelvax QIV. The patient was vaccinated at approximately 26 weeks of gestation and the event was noted on an unspecified date. Chronology needs more clarification. Due to lack of information, causal role of the suspect vaccine is unasseassable. Vaccine exposure during pregnancy is assessed as unrelated per company's conventions.