Chorioamnionitis; Vaccine exposure during pregnancy; This is an observational study case, initially received from other health professional on 16-Jul-2020, concerning a 24-year-old, female pregnant subject of body weight: 112 lbs, height: 66 inches and body mass index (BMI): 18.1, 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 body mass index low, anxiety and depression. The subject was a RhD negative.  The subject's concomitant medications included Prenatal vitamins (unspecified vitamins and minerals) as vitamin, escitalopram for anxiety, Tdap (diphtheria vaccine toxoid, pertussis vaccine acellular, tetanus vaccine toxoid) as vaccine and RhoGram (anti-D immunoglobulin) for RhD negative.  The subject had no obstetrical history. The subject had no history of offspring with major congenital malformation (MCM). The subject had no 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 06-Sep-2019. The type of pregnancy was singleton. The subject's estimated delivery date (EDD) and corrected estimated date of delivery (CEDD) both were reported as 12-Jun-2020.   On 12-Nov-2019, at approximately 9 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: 261223, 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 an unspecified date, unknown amount of time after vaccination, the pregnancy was complicated with chorioamnionitis.  On 03-Dec-2019, the subject underwent maternit 21 test and nuchal translucency, no MCM was noted.  On 17-Dec-2020, the subject underwent ultrasoun scan, no MCM was noted.  On 02-Jan-2020, the subject underwent maternal serum alpha-fetoprotein (MSAFP/serum markers), no MCM was noted.  On 21-Jan-2020, the subject underwent anatomy ultrasound, no MCM was noted.  At gestational age of 39.4 weeks (as reported), the subject vaginally delivered live birth, male neonate. The neonate's birth weight was 3856 grams, length and head circumference were not reported. The appearance, pulse, grimace, activity, and respiration (APGAR) score was at one minute: 8, at five minutes: 9 and at ten minutes: not reported. No MCM was identified at birth. The delivery was complicated with shoulder dystocia.  At the time of this report, the outcome of the event chorioamnionitis was not reported.  The event of chorioamnionitis was assessed as serious due to criterion of medical significance, per the company.  The reporter did not provide causality assessment to Flucelvax QIVc.  The case is linked to case 202003894 (the corresponding baby case).  Company Comment: A pregnant subject experienced amniotic cavity infection on unspecified date in 2020, unknown amount of time after administration of the suspect product Flucelvax QIVc. Chronology needs more clarification. Due to lack of information regarding onset date, diagnostic findings and isolated infection agent, causal role of the suspect vaccine is unassessable. Vaccine exposure during pregnancy is assessed as not related per company conventions.; Sender's Comments: A pregnant subject experienced amniotic cavity infection on unspecified date in 2020, unknown amount of time after administration of the suspect product Flucelvax QIVc. Chronology needs more clarification. Due to lack of information regarding onset date, diagnostic findings and isolated infection agent, causal role of the suspect vaccine is unassessable. Vaccine exposure during pregnancy is assessed as not related per company conventions.