Neonatal abstinence syndrome (NAS); Foetal exposure during pregnancy; This is an observational study case, initially reported by other health professional on 16-Jul-2020, concerning a male, neonate whose mother was 33-year-old, female subject, of body weight 143 lbs, height 64 inches and body mass index (BMI) 24.5, enrolled in a prospective observational safety study on pregnancy outcomes in women immunized with Flucelvax, seasonal cell culture influenza trivalent (TIVc) or quadrivalent (QIVc) vaccine during pregnancy.   The neonate's mother's current condition included anxiety, depression, nausea, post-traumatic stress disorder (PTSD), opioid abuse and cannabis abuse.  The neonate's mother's concomitant medications included diazepam and alprazolam, the both for PTSD, Suboxone (buprenorphine hydrochloride, naloxone hydrochloride) for opioid abuse, Zofran (ondansetron) for nausea, Prenate chewable vitamin (unspecified vitamins and minerals) as vitamin, Subutex (buprenorphine hydrochloride), oxazepam, nordiazepam and Cannabis (cannabis sativa), all for an unknown indication.  The neonate's mother's obstetrical history noted that the subject had one previous pregnancy of full-term live birth with no birth defects and two previous elective abortions. The neonate's mother had no maternal or paternal history with major congenital malformations (MCMs). The neonate's mother had no history of offspring with MCM. The neonate's mother did not use alcohol during pregnancy. However, the neonate's mother used tobacco during pregnancy at unknown amount of product consumed per day. The neonate's mother used illicit drugs during pregnancy including cannabis, alprazolam, oxazepam, nordiazepam and benzodiazepines.  The neonate's mother last menstrual period (LMP) date was on 06-Aug-2019. The estimated delivery date (EDD) was reported as 12-May-2020, while corrected estimated date of delivery (CEDD) was reported as 22-May-2020. The type of pregnancy was singleton. The neonate's father was a 33-year-old.  On 09-Oct-2019, the neonate's mother underwent dating scan and no MCMs were noted.  On 23-Oct-2019, at approximately 12 weeks of gestation (calculated per LMP), the neonate's mother was administered Flucelvax QIVc (Flu Vaccine Cell Subunit QIV NVD) [influenza vaccine, subunit influenza virus vaccine polyvalent; batch number: 261223, dose: 0.5 mL, route of administration, anatomical location and expiration date: not reported] (explicitly coded as 'Foetal exposure during pregnancy') for an influenza immunisation.   On 20-Nov-2019, the neonate's mother underwent first trimester screen and nuchal translucency and no MCMs were noted.  On 12-Dec-2019, the neonate's mother underwent second trimester screen and maternal serum alpha fetoprotein (MSAFP)/ serum markers screening and no MCMs were noted.  On 08-Jan-2020, the neonate's mother underwent anatomy ultrasound and no MCMs were noted.  On 29-Apr-2020, the neonate's mother underwent growth ultrasound and no MCMs were noted.  At approximately 38.4 weeks of gestation (as reported), the subject vaginally delivered a live male neonate. The neonate's birth weight was 3685 grams, while body length and head circumference were not reported. The appearance, pulse, grimace, activity, and respiration (APGAR) score at one minute was 9, at five minutes was 9 and no data was provided at ten minutes. No MCMs were identified at the time of birth.   On an unspecified date in 2020, the neonate developed neonatal abstinence syndrome (NAS) and was admitted to neonatal intensive care unit (NICU).  At the time of this report, the outcome for the event of neonatal abstinence syndrome was not reported.  The event of neonatal abstinence syndrome was considered as serious due to criterion of medical significance and hospitalisation, per company.  The causality assessment was not provided.  This case is linked to the case 202003898 (the corresponding mother's case).  Company comment: A 33-year-old pregnant subject was administered Flucelvax QIVc at gestational age of 12 weeks. The subject vaginally delivered a live male neonate. On an unspecified date in 2020, the neonate developed neonatal abstinence syndrome (NAS) and was admitted to neonatal intensive care unit (NICU). Reportedly, the subject's current condition included opioid abuse and cannabis abuse. Causal role of the suspect vaccine is assessed as not related due to biological implausibility. Foetal exposure during pregnancy is not related per company's conventions.; Sender's Comments: A 33-year-old pregnant subject was administered Flucelvax QIVc at gestational age of 12 weeks. The subject vaginally delivered a live male neonate. On an unspecified date in 2020, the neonate developed neonatal abstinence syndrome (NAS) and was admitted to neonatal intensive care unit (NICU). Reportedly, the subject's current condition included opioid abuse and cannabis abuse. Causal role of the suspect vaccine is assessed as not related due to biological implausibility. Foetal exposure during pregnancy is not related per company's conventions.