Delivery at gestational age of 36.9 weeks; Acid reflux; Vaccine exposure during pregnancy; Nausea; This is an observational study case, initially received from other health professional on 18-Dec-2019, concerning a 31-year-old pregnant, female subject of body weight 192.5 lbs, height 62.8 inches and body mass index (BMI) 34.3, enrolled in a prospective observational safety study.  The subject's current condition included high body mass index and anemia.   The subject's concomitant medications included Prenatal (unspecified vitamins and minerals) + DHA (docosahexaenoic acid) for pregnancy and iron for anemia.  The subject's obstetrical history included three previous pregnancies: one full term live birth and two spontaneous abortions. The subject had no history of offspring with major congenital malformation (MCM), nor maternal or paternal history with MCM. The subject did not use tobacco, alcohol or illicit drugs during pregnancy.   The subject's last menstrual period (LMP) date was 23-Apr-2019. The subject's estimated date of delivery (EDD) was 28-Jan-2020 and corrected estimated date of delivery (CEDD) was 30-Jan-2020. The type of pregnancy was singleton.   On 05-Nov-2019, the subject underwent ultrasound and no MCM was noted.  On 06-Nov-2019, at gestational age of 28 weeks, the subject was administered Afluria QIV [influenza vaccine, subunit influenza virus vaccine polyvalent, cell cultured derived; batch number: P100126099, dose, route of administration, anatomical location and expiration date: not reported] (explicitly coded as 'Vaccine exposure during pregnancy') for influenza immunisation.   On an unspecified date in 2019, after vaccination, the patient experienced nausea.  On 04-Dec-2019, the patient developed acid reflux and was treated with one capsule of Nexium (esomeprazole magnesium) at a dose of 25 mg, every day via oral route of administration. On the same day, the patient started treatment for nausea with one tablet of Zofran (ondansetron hydrochloride) at a dose of 4 mg, every eight hours as needed via oral route of administration.  At gestational age of 36.9 weeks, the subject vaginally delivered male neonate. The birth weight of the neonate was 2750 g, head circumference was 34 cm and length were 44.5 cm. Appearance, pulse, grimace, activity and respiration (APGAR) score at one minute was 8, at five minutes was 9 and no data was reported for APGAR score at ten minutes. No pregnancy complications were noted and no MCM was identified at birth.  Outcome of the events of nausea and acid reflux was not resolved.  The event of premature delivery was considered serious due the criterion of medical significance.  The reporter did not provide the causality assessment to Afluria QIV.  This case is linked to case 202000511, the corresponding child case.  Follow up received from other health professional on 17-Jan-2020: Outcome of pregnancy provided. New event of premature delivery added. Narrative updated accordingly.    Company comment: The patient experienced gastroesophageal reflux disease, nausea and premature delivery associated with Flu Vaccine Egg Split QIV CSL. Chronology seems compatible. The subject's current condition included high body mass index and anaemia and concomitant medications were prenatal (unspecified vitamins and minerals) + DHA (docosahexaenoic acid) for pregnancy and iron for anaemia. With information provided, causality is assessed as unlikely related for the events of gastroesophageal reflux disease and premature delivery, not related for nausea (confounded with iron and pregnancy) and not related for exposure during pregnancy per company conventions.; Sender's Comments: The patient experienced gastroesophageal reflux disease, nausea and premature delivery associated with Flu Vaccine Egg Split QIV CSL. Chronology seems compatible. The subject's current condition included high body mass index and anaemia and concomitant medications were prenatal (unspecified vitamins and minerals) + DHA (docosahexaenoic acid) for pregnancy and iron for anaemia. With information provided, causality is assessed as unlikely related for the events of gastroesophageal reflux disease and premature delivery, not related for nausea (confounded with iron and pregnancy) and not related for exposure during pregnancy per company conventions.