Failure to progress in first stage; Vaccine exposure during pregnancy; Gestational hypertension; This is an observational study case, initially received from other health professional on 20-jan-2020, concerning a 24-year-old, female pregnant subject of body weight: 112 lbs, height: 61 inches and body mass index (BMI): 21.2 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 depression, inguinal hernia, cannabis abuse and nausea. The subject was RhD negative.  The subject's concomitant medications included Phenergan (promethazine hydrochloride) for nausea, Rhogam (anti-D immunoglobulin) for prophylaxis against RH isoimmunisation (reported as RhD negative') and Prenatal (unspecified vitamins and minerals) as vitamin supplementation.  The subject had no previous pregnancies. The subject had no maternal or paternal history with major congenital malformation (MCM).   The subject's last menstrual period (LMP) date was 05-Apr-2019. The type of pregnancy was singleton. The subject's estimated delivery date (EDD) and corrected estimated delivery date (CEDD) were both 10-Jan-2020. The subject did not consume tobacco and alcohol during pregnancy, but consumed cannabis.  On 03-Jul-2019, the subject underwent first trimester screen and nuchal translucency and no MCM was noted.  On 29-Jul-2019, the subject underwent second trimester screen and maternal serum alpha-fetoprotein (MSAFP/serum markers) and no MCM was noted.  On 16-Aug-2019, the subject underwent anatomy scan and no MCM was noted.  On 18-Oct-2019, at gestational age of 28 weeks, the subject was administered Flucelvax QIVc (Flu Vaccine Cell Subunit QIV NVD) [influenza vaccine, subunit influenza virus vaccine polyvalent, batch number: 261223, dose, route of administration, anatomical location and expiry date: not reported) (explicitly coded as Vaccine exposure during pregnancy') for influenza immunisation.  On the same day, the subject was also administered a non-company co-suspect vaccine TDAP [diphtheria vaccine toxoid, pertussis vaccine acellular, tetanus vaccine toxoid, dose: 0.5 ml, route of administration: intramuscular, anatomical location, batch number and expiry date: not reported) as vaccine.  On an unspecified date in 2019, the subject developed gestational hypertension.  On 25-Dec-2019, at gestational age of 37.7 weeks, the subject delivered female neonate by caesarean method. The labour was complicated with failure to progress in first stage. The birth weight of the neonate was 2948 g. No data was provided for head circumference and length. Appearance, pulse, grimace, activity and respiration (APGAR) score at one minute was 8, at five minutes was 8. No data was reported for APGAR score at ten minutes. No MCM was identified at birth.  At the time of this report, the outcome of gestational hypertension and failure to progress in first stage was not reported.  The event of  failure to progress in first stage was considered serious due to the criterion of medical significance, per company.  The reporter did not provide the causality assessment to Flucelvax QIV.  Company comment: The subject experienced labour complication and gestational hypertension after vaccination with the suspect product, Flucelvax QIVc. Reportedly, vaccination occurred during pregnancy at gestational age of 28 weeks. Chronology is plausible. Medical history of inguinal hernia, cannabis abuse and pregnant state may provide alternative aetiology for the events. Non-company co-suspect vaccine TDAP (diphtheria vaccine toxoid, pertussis vaccine acellular, tetanus vaccine toxoid) and concomitant medication Phenergan (promethazine hydrochloride) confound causality in significant way. Vaccine exposure during pregnancy is assessed as not related per company's conventions. Considering all the above mentioned, causality between suspect product and the events labour complication and gestational hypertension is assessed as unlikely related (defaults to related for reporting purposes).; Sender's Comments: The subject experienced labour complication and gestational hypertension after vaccination with the suspect product, Flucelvax QIVc. Reportedly, vaccination occurred during pregnancy at gestational age of 28 weeks. Chronology is plausible. Medical history of inguinal hernia, cannabis abuse and pregnant state may provide alternative aetiology for the events. Non-company co-suspect vaccine TDAP (diphtheria vaccine toxoid, pertussis vaccine acellular, tetanus vaccine toxoid) and concomitant medication Phenergan (promethazine hydrochloride) confound causality in significant way. Vaccine exposure during pregnancy is assessed as not related per company's conventions. Considering all the above mentioned, causality between suspect product and the events labour complication and gestational hypertension is assessed as unlikely related (defaults to related for reporting purposes).