Arrest of dilation; Vaccine exposure during pregnancy; This is an observational study case, initially received from other health professional on 07-Jul-2020, concerning a 35-year-old, pregnant, female subject of body weight 161 lbs, height 66 inches and body mass index (BMI) 26, enrolled in a prospective observational study.  The subject's current medical conditions included advanced maternal age, BMI increased, nausea and vomiting.  The subject's concomitant medications included Prenatal vitamins (unspecified vitamins and minerals) as vitamin, Diclegis (doxylamine succinate, pyridoxine hydrochloride) for nausea.  The subject's obstetrical history noted that the subject had two previous pregnancies with one full-term live birth and one molar pregnancy. The subject had no maternal or paternal history with major congenital malformations (MCMs). The subject had no history of offspring with MCMs. The subject did not use tobacco, alcohol or illicit drugs during pregnancy.  The subject's last menstrual period (LMP) date was 10-Sep-2019, the estimated delivery date (EDD) was 16-Jun-2020 while the corrected estimated data of delivery (CEDD) was reported as 23-Jun-2020. The type of pregnancy was singleton.  On 03-Dec-2019, the subject underwent ultrasound and no MCMs were noted.   On 16-Dec-2019, at approximately 13 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; dose: 0.5 ml, batch number: 261223, anatomical location, route of administration and expiration date: not reported] (explicitly coded as Vaccine exposure during pregnancy') for an influenza immunisation.   On the same day, the subject underwent nuchal translucency test and no MCMs were noted.  On 09-Jan-2020, the subject underwent maternal serum alpha-fetoprotein screening (MSAFP) / serum markers and second trimester screen. No MCMs were noted.  On 30-Jan-2020, the subject underwent anatomy ultrasound and no MCMs were noted.  At gestational age of 39 weeks (as reported), the subject delivered live female neonate by caesarean method due to arrest of dilation (AOD). The neonate's birth weight was 3260 g, head circumference and length were not reported. Appearance, pulse, grimace response, activity, respiration (APGAR) score in one minute was 1, in five minutes was 8 and in ten minutes was 9. Foetal intolerance was noted as pregnancy complication during delivery. No MCMs noted at birth.  On the same day, the outcome of the event arrested labour' was resolved.  The event of arrested labour' was considered as serious due to the criterion of medical significance, per company.   The reporter did not provide causality assessment to Flucelvax QIV.  This case is linked to case 202003844, corresponding baby case.  Company comment: A pregnant subject was administered Flucelvax QIVc at 13 weeks of gestation. The subject experienced arrested labour 6 months after vaccination. Causality was confounded by medical history of advanced maternal age, BMI increased. Causal role of the suspect vaccine is assessed as not related due to implausible temporal relationship and biological implausibility. Vaccine exposure during pregnancy assessed as not related per company's conventions.; Sender's Comments: A pregnant subject was administered Flucelvax QIVc at 13 weeks of gestation. The subject experienced arrested labour 6 months after vaccination. Causality was confounded by medical history of advanced maternal age, BMI increased. Causal role of the suspect vaccine is assessed as not related due to implausible temporal relationship and biological implausibility. Vaccine exposure during pregnancy assessed as not related per company's conventions.