16-week intrauterine fetal demise (no fetal heart tones)/spontaneous abortion; Urinary tract infection; Vaccine exposure during pregnancy; This is an observational study case, initially received from other health professional on 20-Jul-2020, concerning a 29-year-old, female pregnant subject of body weight: 199 lbs, height: 65 inches and body mass index (BMI): 33.1, who was enrolled in, a prospective observational safety study on pregnancy outcomes in women immunized with seasonal cell culture influenza trivalent (TIVc) or quadrivalent (QIVc) vaccine during pregnancy.  The subject's medical history included chronic hypertension and high BMI.  The subject's concomitant medications included Prenatal vitamin (unspecified vitamins and minerals) for pregnancy.  The subject's obstetrical history included one previous pregnancy with one full term live birth. The subject had no history of offspring with major congenital malformation (MCM). The subject had no relevant maternal and paternal history with MCMs. The subject did not use tobacco, illicit drug or alcohol during pregnancy.  The subject's last menstrual period (LMP) date was reported as 17-Aug-2019, while the estimated delivery date (EDD) and corrected estimated date of delivery (CEDD) both were reported as 23-May-2020. The type of pregnancy was singleton.   On 30-Sep-2019, the subject underwent ultrasound and no MCM was noted.  On 03-Oct-2019, the subject underwent spinal muscular atrophy and cystic fibrosis mutation test and no MCM was noted.  On 13-Nov-2019, at gestational age of 12 weeks (calculated per LMP), the subject was administered Flucelvax QIVc (Flu Vaccine Cell Subunit QIV NVD) [influenza vaccine, subunit influenza virus vaccine polyvalent; dose: 0.5 ml, batch number: 261228, anatomical location, route of administration and expiration date: not reported] (explicitly coded as Vaccine exposure during pregnancy') for influenza immunisation. On the same day, the subject underwent panorama test and no MCM was noted.   On the same day, the subject developed urinary tract infection (UTI) and started treatment with Macrobid (nitrofurantoin), at a dose of one tablet, twice daily, orally.  On 20-Nov-2019, the outcome of the event UTI was resolved and the subject stopped treatment with Macrobid.  On 11-Dec-2019, at gestational age of 16 weeks, 28 days after vaccination, the subject underwent ultrasound and intrauterine foetal demise was noted (no foetal heart tones seen).  On 12-Dec-2019, the subject experienced spontaneous abortion. It was unknown if the foetus had MCM.   At the time of this report, the outcome of the event spontaneous abortion' was not reported.   The events of  spontaneous abortion' and UTI were considered serious due to criteria of medical significance, per company.  The reporter did not provide causality assessment to Flucelvax QIV.  Company comment: Spontaneous abortion and urinary tract infection were associated with the use of the suspect product Flucelvax QIVc for influenza immunisation. The subject developed urinary tract infection (UTI) on the same day when our product was given making chronology unsuggestive. Twenty-eight days after vaccination, the subject underwent ultrasound and intrauterine foetal demise was noted (no foetal heart tones seen). Chronology seems compatible. The subject's medical history included chronic hypertension and high BMI, while concomitant medications included unspecified prenatal vitamins for pregnancy. With information presented, causality is assessed as unrelated for UTI due to biological and chronological implausibility and not related for spontaneous abortion due to reported chronic hypertension and high BMI. Vaccine exposure during pregnancy assessed as not related per company's conventions.; Sender's Comments: Spontaneous abortion and urinary tract infection were associated with the use of the suspect product Flucelvax QIVc for influenza immunisation. The subject developed urinary tract infection (UTI) on the same day when our product was given making chronology unsuggestive. Twenty-eight days after vaccination, the subject underwent ultrasound and intrauterine foetal demise was noted (no foetal heart tones seen). Chronology seems compatible. The subject's medical history included chronic hypertension and high BMI, while concomitant medications included unspecified prenatal vitamins for pregnancy. With information presented, causality is assessed as unrelated for UTI due to biological and chronological implausibility and not related for spontaneous abortion due to reported chronic hypertension and high BMI. Vaccine exposure during pregnancy assessed as not related per company's conventions.