Vaccine fetal exposure during pregnancy; Low birth weight of 2240 g; Preterm birth at gestational age of 35.7 weeks; This is a spontaneous case, initially received on 20-Jan-2020, concerning a female neonate patient, whose mother was 29-year-old, pregnant subject of body weight: 99.78 kg, height: 167.64 cm and body mass index (BMI): 35.5.   The mother's medical history included: anxiety, obesity, nausea, gastroesophageal reflux disease, nausea, cholestasis and anaemia.  The mother's concomitant medication included: Zantac (ranitidine hydrochloride) for gastroesophageal reflux disease, Multivitamin (vitamins NOS) as vitamin, promethazine for nausea, Actigall (ursodeoxycholic acid) for cholestasis, Ferralet 90 [ascorbic acid; cyanocobalamin; docusate sodium; ferrous gluconate; folic acid; iron pentacarbonyl] and intravenous iron, both used for anemia.  The mother's obstetrical history included one previous pregnancy of full term live birth. The patient had no history of offspring with major congenital malformation (MCM) and no relevant maternal and paternal medical history. The mother did not use tobacco, alcohol or illicit drugs during pregnancy.   The mother's last menstrual period (LMP) date was 21-Apr-2019. The type of pregnancy was multiple (twins). The patient's estimated delivery date (EDD) and corrected estimated date of delivery (CEDD) were both 24-Jan-2020.  On 11-Jun-2019, the patient's mother underwent ultrasound scan and no MCM was noted.  On 22-Jul-2019, the patient's mother underwent first trimester screen and nuchal translucency screen and no MCM was noted.  On 12-Aug-2019, the patient's mother underwent maternal serum alpha-fetoprotein (MSAFP/serum markers) analysis and no MCM was noted. On the same day the patient's mother underwent second trimester screen and results were positive for open spina bifida (OSB).   On 14-Aug-2019 the patient's mother underwent ultrasound scan and MCM was noted.  On 11-Sep-2019, the patient's mother underwent anatomy ultrasound scan and no MCM was noted.   On 11-Sep-2019, approximately at 20 weeks of gestation, the patient's mother was administered Flucelvax QIV [influenza vaccine, subunit influenza virus vaccine polyvalent; batch number: 261200; dose: 0.5 ml, route of administration: intramuscular, anatomical location and expiration date: not reported] (explicitly coded as 'Foetal exposure during pregnancy') for an unknown indication.   On 08-Nov-2019, the patient's mother performed glucose tolerance test and result was abnormal.   On 20-Nov-2019, the mother's liver enzymes were elevated.   Approximately at 35.7 weeks of gestation, the patient's mother delivered two premature live female neonates by Caesarean method. The characteristics of one neonate included weight of 2240 grams, head circumference of 33 cm and length which was 45.1 cm. The patient's appearance, pulse, grimace, activity, and respiration (APGAR) score was 8 at one minute and 9 at five minutes. No APGAR score data for 10 minutes was reported. No MCM was identified at birth.  At the time of initial reporting, the outcome of low birth weight and preterm birth was not reported.  Per company, the events of low birth weight and preterm birth were considered as serious due to the criterion of medical significance.  The reporter did not provide causality assessment to Flucelvax QIV.  This case is linked to 201907195 (the corresponding mother case) and 202000593 (the corresponding baby sister case).  Company comment: The female neonate patient developed low birth weight and premature birth after vaccination of her mother (approximately at 20 weeks of gestation) with the suspect product Flucelvax QIV. Chronology seems plausible. The patient's mother current conditions included increased obesity with body mass index 35.5, anxiety, nausea and gastroesophageal reflux disease (GERD). The patient's mother concomitant medication included promethazine for nausea, unspecified multivitamin (vitamins NOS) as vitamin, Zantac (ranitidine hydrochloride) for GERD, ursodeoxycholic acid and iron. Reportedly, on 12-Aug-2019, (before administration of the vaccine) the patient's mother underwent second trimester screen and results were positive for open spina bifida. Being obese during pregnancy increases the risk of various pregnancy complications, including: the risk of miscarriage, stillbirth, premature birth and recurrent miscarriage. Premature birth could explain low birth weight. With information provided, causality is assessed as not related for both events. Foetal exposure during pregnancy is assessed as not related as well, per company conventions.; Sender's Comments: The female neonate patient developed low birth weight and premature birth after vaccination of her mother (approximately at 20 weeks of gestation) with the suspect product Flucelvax QIV. Chronology seems plausible. The patient's mother current conditions included increased obesity with body mass index 35.5, anxiety, nausea and gastroesophageal reflux disease (GERD). The patient's mother concomitant medication included promethazine for nausea, unspecified multivitamin (vitamins NOS) as vitamin, Zantac (ranitidine hydrochloride) for GERD, ursodeoxycholic acid and iron. Reportedly, on 12-Aug-2019, (before administration of the vaccine) the patient's mother underwent second trimester screen and results were positive for open spina bifida. Being obese during pregnancy increases the risk of various pregnancy complications, including: the risk of miscarriage, stillbirth, premature birth and recurrent miscarriage. Premature birth could explain low birth weight. With information provided, causality is assessed as not related for both events. Foetal exposure during pregnancy is assessed as not related as well, per company conventions.