This is a serious observational study case, initially received from other health professional on 23-May-2019, concerning a 31-year-old, adult, female pregnant subject of body weight: 213.8 lbs, height: 59 inches and body mass index (BMI): 43.2, 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 relevant medical history included a congenital heart defect. The subject's obstetrical history included three previous pregnancies in which there were two full term live births, one was ectopic pregnancy and there were no birth defects reported. The subject had no history of offspring with major congenital malformation and no relevant maternal and paternal medical history. The subject did not use tobacco, alcohol or illicit drugs during pregnancy. The concomitant medications of the subject included Prenatal vitamins (minerals nos, vitamins nos) as supplement. The subject was Rh D negative. The subject's last menstrual period (LMP) date was 24-Aug-2018. The type of pregnancy was singleton. On 04-Oct-2018, at gestational age of 5 weeks, the subject was administered Flu Vaccine Egg Split QIV CSL (influenza vaccine, batch number: YF40408, dose, route of administration, expiry date and anatomical location: not reported) (explicitly coded as vaccine exposure during pregnancy) for an unknown indication. On 15-Oct-2018, 11 days after the vaccine administration, the subject experienced constipation and was treated with Colace (docusate sodium, dose: 1 tablet, prn, orally from 15-Oct-2018 to ongoing). On 26-Oct-2018, the subject underwent ultrasound and no major congenital malformations was noted. On 16-Nov-2018, the subject underwent Sequential 1 (prenatal test), Inheritest core and Nuchal translucency tests and no major congenital malformations were noted. On 13-Dec-2018, the subject underwent Sequential 1 (prenatal test) and no major congenital malformation was noted. On an unknown date, pregnancy status of the subject was collected, and pregnancy complications was noted as marginal umbilical cord insertion. On 22-Mar-2019, 5 months and 18 days after vaccination, the subject experienced polyhydramnios. On 05-Apr-2019, 6 months and 1 day after vaccination, the subject experienced anemia and was treated with iron (dose: 325 mg, qd, oral, from 05-Apr-2019 to ongoing). On 26-Apr-2019, 6 months and 22 days, after vaccination, the subject was found to be positive for group B Streptococcus. The outcome of the events bacterial infection due to streptococcus, group b, polyhydramnios, anemia and constipation was not recovered and outcome of the event umbilical cord abnormality was not reported. The subject's estimated date of delivery (EDD) and corrected estimated date of delivery (CEDD) were reported as 31-May-2019.; Reporter's Comments: A 31-year-old pregnant subject experienced constipation, 11 days after administration of study vaccine, at 5 weeks of gestation (coded to Exposure during pregnancy). The patient also experienced polyhydramnios, 5 months 18 days and beta haemolytic streptococcal infection and anaemia approximately 6 months after vaccination. Despite the plausible temporal relationship between vaccination and reported event (constipation) and no evidence for a biological mechanism that could cause the event, 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 implausible temporal relationship between vaccination and reported events (beta haemolytic streptococcal infection, polyhydramnios and anaemia), no evidence for a biological mechanism that could cause the events and incidental nature of the events, the events were assessed as not related to the study vaccine. The event of umbilical cord abnormality appears to an incidental finding as there is no evidence/investigation suggesting a biological mechanism that could cause the event and was assessed as not related to study vaccine. The medical history/current conditions (congenital heart defect, BMI- 43.2 and prior ectopic pregnancy) confound 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 this case as serious (medically significant).