Placental abruption; Anxiety; Vaccine exposure during pregnancy; Acid reflux; This is an observational study case, initially received from other health professional on 11-Feb-2020, concerning a 32-year-old, female pregnant subject of body weight: 203 lbs, height: 63 inches and body mass index (BMI): 36, enrolled in a prospective observational safety study.  The subject's medical history included increased BMI.  The subject's concomitant medication 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. The subject did not use tobacco, alcohol or illicit drugs during pregnancy.   The subject's last menstrual period (LMP) date was 12-Apr-2019. The type of pregnancy was singleton. The subject's estimated date of delivery (EDD) and corrected estimated date of delivery (CEDD) was reported as 17-Jan-2020.  On 29-May-2019, the subject underwent spinal muscular atrophy test and cystic fibrosis mutation analysis and no MCM was noted.   On 24-Jun-2019, the subject underwent ultrasound scan and no MCM was noted.   On 08-Jul-2019, the subject underwent Panorama test and no MCM was noted.  On 07-Aug-2019, the subject underwent ultrasound scan and no MCM was noted.  On 09-Oct-2019, approximately at 25 weeks of gestation, the subject was administered Flucelvax QIV (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] for an influenza immunization (explicitly coded as ''Vaccine exposure during pregnancy'').  On the same day, after vaccination, the subject experienced acid reflux and started treatment with Prevacid (lansoprazole).  On an unknown date in 2019, unknown after vaccination, the subject experienced placental abruption.  On an unknown date, unknown after vaccination, the subject experienced anxiety.   Approximately at 38.1 weeks of gestation, the subject delivered a normal, female neonate by Caesarean method. The neonate's birth weight was 2722 grams, body length: 48.3 cm and head circumference: 34.3 cm. The appearance, pulse, grimace, activity, and respiration (APGAR) scores were 8 at one minute and 8 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 subject did not recover from the events of acid reflux and anxiety, while the outcome of abruptio placentae' was not reported.   Per company, the event of abruptio placentae' was considered serious due to the criterion of medical significance.   The reporter did not provide causality assessment to Flucelvax QIV.   Company comment: It is unknown when the placental abruption and anxiety developed therefore causality for these events was considered unassessable. Temporal relationship between vaccination and development of gastric acid reflux is plausible. Causality assessment is confounded by pregnancy and increased BMI. Nevertheless, the event of acid reflux was assessed as possibly related to Flucelvax (defaults to 'related' causality for reporting purposes).; Sender's Comments: It is unknown when the placental abruption and anxiety developed therefore causality for these events was considered unassessable. Temporal relationship between vaccination and development of gastric acid reflux is plausible. Causality assessment is confounded by pregnancy and increased BMI. Nevertheless, the event of acid reflux was assessed as possibly related to Flucelvax (defaults to 'related' causality for reporting purposes).