Spontaneous abortion; Vaccine exposure during pregnancy; This is an observational study case, initially received from other health professional on 09-Jun-2020, concerning a 41-year-old pregnant, female subject of body weight 228 lbs, height 64 inches and body mass index (BMI) 39.1, enrolled in a prospective observational safety study.  The subject's medical history included anxiety, herpes simplex virus 1 and 2, chronic hypertension, high BMI and pregnancy with advanced maternal age.  The subject's concomitant medications included Prenatal vitamins (unspecified vitamins and minerals) for pregnancy and Effexor (venlafaxine hydrochloride) for anxiety.  The subject's obstetrical history included two previous pregnancies with one preterm live birth and one full term live birth. The subject had no history of offspring with major congenital malformation (MCM). The subject had no maternal and paternal history with MCMs. The subject did not consume tobacco, alcohol and illicit-drugs during pregnancy.  The subject's last menstrual period (LMP) date was on 29-Aug-2019. The subject's estimated delivery date (EDD) was reported as 05-Jun-2020 and corrected estimated delivery date (CEDD) was reported as 04-Jun-2020. The type of pregnancy was singleton.  On 08-Oct-2019, the subject underwent cystic fibrosis mutation analysis and spinal muscular atrophy, and no MCMs were noted.  On 09-Oct-2019, the subject underwent ultrasound and no MCMs were noted.  On 17-Oct-2019, at approximately 7 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, batch number: 261218, dose: 0.5 ml, route of administration, anatomical location and expiry date: not reported) (explicitly coded as Vaccine exposure during pregnancy') for influenza immunisation.  On 23-Oct-2019 and 04-Nov-2019, the subject underwent ultrasound and no MCMs were noted.  On 21-Nov-2019, the subject underwent panorama and ultrasound, and no MCMs were noted.  On 19-Dec-2019, the subject underwent ultrasound and no MCMs were noted.  On 22-Dec-2019, the subject underwent ultrasound and fetal demise, no fetal heart tones were noted.  On 27-Dec-2019, approximately two months and 10 days after vaccination, at gestational age of 16 weeks (as reported), the subject had spontaneous abortion. It was not reported cause for a foetal loss.  At the time of initial reporting, the outcome for the event of spontaneous abortion was not reported.  Per company, the event of spontaneous abortion' was considered serious due to the criterion of medical significance.  The reporter did not provide the causality assessment to Flucelvax QIV.  Company comment: A pregnant subject experienced abortion spontaneous 2 months and 10 days after receiving Flucelvax QIV. The subject's medical history included herpes simplex virus 1 and 2, chronic hypertension, high BMI and advanced maternal age, therefore causality was confounded. Causal role of the suspect vaccine is assessed as not related, due to biological implausibility and unsuggestive chronology. Vaccine exposure during pregnancy assessed as not related per company's conventions.; Sender's Comments: A pregnant subject experienced abortion spontaneous 2 months and 10 days after receiving Flucelvax QIV. The subject's medical history included herpes simplex virus 1 and 2, chronic hypertension, high BMI and advanced maternal age, therefore causality was confounded. Causal role of the suspect vaccine is assessed as not related, due to biological implausibility and unsuggestive chronology. Vaccine exposure during pregnancy assessed as not related per company's conventions.