Pre-eclampsia; Acid reflux; Vaccine exposure during pregnancy; This is a serious observational study case initially received on 13-May-2019, concerning a 28-year-old adult, female, pregnant subject of body weight 150.5 lbs, height 65.5 inches and body mass index (BMI) 24.7, enrolled in a prospective observational safety study on pregnancy outcomes in women immunized with Afluria QIV, a seasonal quadrivalent vaccine, during pregnancy.  The subject's obstetrical history included three previous pregnancies which includes two full term live births and one spontaneous abortion. The subject had no history of offspring with major congenital malformation. Also, the subject had no maternal or paternal history with major congenital malformations. The subject didn't have a prior history of use of tobacco, alcohol or illicit drugs during pregnancy. The pregnancy status of the subject was collected, and no pregnancy complications were noted.  The subject's current conditions included hypothyroidism and nausea. The subject's concomitant medication included Prenatal vitamins (Vitamins and Minerals NOS) for pregnancy, Diclegis (doxylamine succinate, pyridoxine hydrochloride) for nausea, Zofran (ondansetron) for nausea (reported as Zofran orally disintegrating tablet (ODT)).  The subject's last menstrual period date was 12-Oct-2018 and type of pregnancy was singleton.  On 05-Dec-2018, the subject underwent ultrasound and no major congenital malformation was noted.  On 12-Dec-2018, the subject was administered Flu Vaccine Egg Split QIV CSL [batch number: YF41608, dose, route of administration, expiry date and anatomical location: not reported] (explicitly considered as vaccine exposure during pregnancy) for an unknown indication.  On 06-Feb-2019, 1 month and 25 days after administration of study vaccine, the subject experienced acid reflux (oesophageal) and was treated with Zantac (ranitidine) [dose: 150 mg, frequency: QD, route: oral, start date: 06-Feb-2019 and stop date: ongoing] at gestational age of 16.7 weeks.  On 22-Feb-2019, the subject underwent ultrasound and no major congenital malformation was noted.  At gestation age of 37 weeks, the subject gave a live birth to a male neonate by caesarean method. At the time of delivery pregnancy complication was noted as Pre-eclampsia. Th characteristics of the neonate included birth weight: 3060 grams, head circumference: 33.5 cm, body length: 49 cm, appearance, pulse, grimace, activity, and respiration (APGAR) scores were 7 at one minute and 8 at five minutes). The subject had no major congenital malformations identified at birth.   The outcome of the event acid reflux was not recovered, and pre-eclampsia was not reported.  The subject's estimated date of delivery was reported as 19-Jul-2019 and corrected estimated date of delivery was reported as 19-Jul-2019.  Follow-up received from the other healthcare professional on 11-Jul-2019: The pregnancy outcome details (gestational age at birth: 37 weeks, delivery date: 28-Jun-2019, outcome: live birth, delivery method: caesarean) and neonate characteristics (gender: male, birth weight: 3060 grams, head circumference: 33.5 cm, body length: 49 cm, APGAR score: 7 at one minute, 8 at five minutes and ten minutes: no data) were added in the patient tab. New event pre-eclampsia was added and the case upgraded from non-serious' to serious' in the event tab. The narrative and case comment were amended accordingly.; Reporter's Comments: A 28-year-old pregnant subject experienced acid reflux, one month 25 days after administration of study vaccine administered at 08 weeks of gestation (coded to Exposure during pregnancy).  The subject also experienced pre-eclampsia 6 months 16 days post vaccination. Despite the plausible temporal relationship between vaccination and reported event (acid reflux), there is no evidence for a biological mechanism that suggests a causal role and the event was assessed as not related to the vaccination as underlying pregnancy appears to be a more likely explanation rather than study vaccine. Considering the timeframe of event with respect to vaccine administration (pre-eclampsia), no evidence for a biological mechanism/investigation suggesting a causal role and current condition (hypothyroidism), the event was assessed as not related to the study vaccine. The gestational history  (two full term live births and one spontaneous abortion) further confounds this case. The decision to administer a vaccine during pregnancy is related to medical decision making by the mother and her physician and is not related to any property of the medication. The event of exposure during pregnancy was assessed as not related considering the intended use of the vaccine The company assessed the case as serious (medically significant).