Fetal exposure during pregnancy; Low birth weight of 1979 g; Preterm birth at 35.7 weeks of gestation; This is a serious spontaneous case, initially received from other health professional on 20-Jan-2020, concerning a female neonate patient.  The patient's mother was a 29-year-old, femal of body weight: 220 lbs, height: 66 inches and body mass index (BMI): 35.5.  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 and Zantac (ranitidine hydrochloride) for GERD.  The patient's mother obstetrical history included one previous pregnancy with one full term live birth. The patient's mother had no history of offspring with major congenital malformation (MCM). Also, the patient's mother had no maternal or paternal history with MCM. The patient's mother did not have a prior history of use of tobacco, alcohol or illicit drugs during pregnancy.   The patient's mother last menstrual period date (LMP) was 21-Apr-2019. The estimated delivery date (EDD) and corrected estimated delivery date (CEDD) were reported as 24-Jan-2020. The type of pregnancy was multiple (twins). The subject's father was 30-year-old.  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 had MSAFP/serum markers analysis and no MCM was noted. On the same day, the patient underwent second trimester screen and results were positive for open spina bifida.   On 14-Aug-2019 the patient's mother underwent ultrasound scan and no 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' 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 23-Oct-2019, the patient's mother developed anemia and started treatment with Ferralet (ascorbic acid, cyanocobalamin, docusate sodium, ferrous gluconate, folic acid, iron pentacarbonyl).  On 06-Nov-2019,  the patient's mother developed cholestasis.  On 08-Nov-2019, the patient's mother had abnormal glucose tolerance test.  On 18-Nov-2019, the patient's mother started treatment with Actigall (ursodeoxycholic acid) for cholestasis.  On 20-Nov-2019,  the patient's mother developed elevated liver enzymes.  On 27-Nov-2019,  the patient's mother received unspecified intravenous (IV) iron for anemia.  At gestational age of 35.7 weeks, the mother delivered two premature live female neonates by caesarean method. The characteristics of the second neonate included: birth weight 1979 grams, head circumference: 30.8 cm, length: 44.5 cm and APGAR scores were 8 (one minute) and 9 (five minutes). There was no APGAR score data for 10 minutes reported for both neonates. No MCMs were identified at birth.  At the time of initial reporting, the outcome of the events of premature birth and low birth weight baby was not reported.  The events of premature birth and low birth weight baby were considered serious due to the criterion of medical significance, per company.  The reporter did not provide causality assessment.  This case is linked to cases 201907195 (corresponding mother case) and 202000595 (corresponding twin baby).  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 and Zantac (ranitidine hydrochloride) for GERD. 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 and Zantac (ranitidine hydrochloride) for GERD. 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.