Urinary tract infection; Vaccine exposure during pregnancy; This is an observational study case, initially received from other health professional on 23-Dec-2019, concerning a 26-year-old, pregnant, female subject of body weight: 294 lbs, height: 61.3 inches and body mass index (BMI): 55, enrolled in a prospective observational safety study. Paternal age was 28 years.   The subject's current medical condition included: depressive disorder, bipolar disorder, anxiety, and obesity. The subject had history of C-section and gestational hypertension. The concomitant medications of the subject included Vitamins (unspecified vitamins) as OB supplement, sertraline for depressive disorder and fluoxetine for bipolar disorder.   The subject's obstetrical history included one previous pregnancy with one full-term live birth. The paternal medical history included malignant breast tumour of subject's grandmother. The subject had no history of offspring with major congenital malformation (MCM) and no relevant maternal medical history. The subject did not use tobacco, alcohol or illicit drugs during pregnancy.  The subject's last menstrual period (LMP) date was 25-Mar-2019. The subject's estimated date of delivery (EDD) was reported as 30-Dec-2020 and corrected estimated date of delivery (CEDD) was reported as 29-Jan-2020. The type of pregnancy was singleton.  On 20-Aug-2019, the subject underwent ultrasound scan and no MCM was noted.  On 17-Sep-2019, the subject underwent anatomy ultrasound scan and no MCM was noted.  On 16-Oct-2019, at 25 weeks of gestation, the subject was administered Flu Vaccine Cell Subunit QIV NVD (Flucelvax QIV) [influenza vaccine, subunit influenza virus vaccine polyvalent, dose: 0.5 ml, batch number: 261727, route of administration, anatomical location and expiration date: not reported] (explicitly coded as 'Vaccine exposure during pregnancy') for influenza immunisation.  On 07-Nov-2019, at 28 weeks of gestation, the subject was administered Tdap [diphtheria vaccine toxoid, pertussis vaccine acellular, tetanus vaccine toxoid, dose: 0.5 ml; route of administration: intramuscular; anatomical location, batch number and expiration date: not reported] as vaccine.  On 03-Dec-2019, one month and 17 days after flu vaccination and 26 days after Tdap, the subject developed urinary tract infection and was treated with Macrobid (clarithromycin) at dose of one capsule every 12 hours, orally for another five days.   On 08-Dec-2019, the outcome of event was resolved.   Per company, the event of urinary tract infection was considered serious due to criterion of medical significance.    The reporter did not provide causality assessment to Flucelvax (QIV).  Company comment: The subject experienced urinary tract infection after vaccination with the suspect product, Flucelvax QIV. Reportedly, vaccination occurred during pregnancy at 25 weeks of gestation. Chronology is plausible. Medical history of obesity (body mass index: 55) and pregnant state may provide alternative aetiology for the event. Causality is also confounded with co-suspect product Tdap (diphtheria vaccine toxoid, pertussis vaccine acellular, tetanus vaccine toxoid) concomitant medications, sertraline and fluoxetine. Vaccine exposure during pregnancy is assessed as not related per company's conventions. Causality between suspect product and the event urinary tract infection is assessed as unlikely related (defaults to related for reporting purposes).; Sender's Comments: The subject experienced urinary tract infection after vaccination with the suspect product, Flucelvax QIV. Reportedly, vaccination occurred during pregnancy at 25 weeks of gestation. Chronology is plausible. Medical history of obesity (body mass index: 55) and pregnant state may provide alternative aetiology for the event. Causality is also confounded with co-suspect product Tdap (diphtheria vaccine toxoid, pertussis vaccine acellular, tetanus vaccine toxoid) concomitant medications, sertraline and fluoxetine. Vaccine exposure during pregnancy is assessed as not related per company's conventions. Causality between suspect product and the event urinary tract infection is assessed as unlikely related (defaults to related for reporting purposes).