Fetal exposure during pregnancy; Premature baby; Neonate's birth weight was 2041g; This is a serious retrospective pregnancy study case, initially received from other health professional on 07-Aug-2019, concerning a neonate, male subject, whose mother was a 21-year-old, pregnant, female subject of body weight 97 lbs, height 60 inches and body mass index (BMI) 18,9, 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 mother's medical history included: tobacco use during pregnancy (one pack per day), bacterial vaginosis, muscle spasms, acid reflux and herpes type 2. Concomitant medications included Prenatal vitamins (mineral NOS, vitamins NOS), Metrogel (metronidazole), ciclopirox and Zantac (ranitidine hydrochloride).  The subject's mother obstetrical history noted that the mother had no previous pregnancies. Also, the subject's mother had no maternal or paternal history with major congenital malformations. The mother did not have a prior history of use of alcohol or illicit drugs during pregnancy. The mother's last menstrual period (LMP) date was 01-Mar-2018 and the pregnancy was singleton. The estimated delivery date (EDD) and the corrected estimated date of delivery (CEDD) were 06-Dec-2019.   On 08-Oct-2018, at gestation age of 31 weeks, the subject's mother was administered Flucelvax QIVc [influenza vaccine, subunit influenza virus vaccine polyvalent, at a dose of 0.5 ml, batch number: 252664, expiration date, route of administration, and anatomical location: not reported] (explicitly coded as fetal exposure during pregnancy'] for influenza immunisation.  On, at gestational age of 36.4 weeks, the mother vaginally delivered live birth, male neonate [explicitly coded as Premature baby']. The neonate's birth weight was 2041 g, his head circumference and length were not reported. The appearance, pulse, grimace, activity, and respiration (APGAR) scores were 8 (one minute) and 9 (five minutes). There was no major congenital malformation identified at birth.  At the time of initial reporting, the outcome of the events 'premature baby' and 'low birth weight baby' was not reported.  This case is linked to 201904363, corresponding mother case.  Company comment: The patient experienced preterm birth and low birth weight, one months and three days after maternal receipt of Flu Vaccine Cell Subunit QIV NVD. Chronology is plausible. Mother's medical history of bacterial vaginosis, muscle spasms, acid reflux, herpes infection type II, tobacco used and concomitant drugs (metronidazole and ranitidine hydrochloride) used during pregnancy may have contributed to development of the events. However, causal role of the suspect vaccine cannot be totally excluded and is assessed as related to the events of preterm birth and low birth weight. The event foetal exposure during pregnancy was assessed as not related considering the intended use of the vaccine.; Reporter's Comments: The patient experienced preterm birth and low birth weight, one months and three days after maternal receipt of Flu Vaccine Cell Subunit QIV NVD. Chronology is plausible. Mother's medical history of bacterial vaginosis, muscle spasms, acid reflux, herpes infection type II, tobacco used and concomitant drugs (metronidazole and ranitidine hydrochloride) used during pregnancy may have contributed to development of the events. However, causal role of the suspect vaccine cannot be totally excluded and is assessed as related to the events of preterm birth and low birth weight. The event foetal exposure during pregnancy was assessed as not related considering the intended use of the vaccine.