Vaccine exposure during pregnancy; Low laying placenta; This observational study case, initially received on 14-Dec-2020 from other health professional and concerned a 33-year-old pregnant, female subject of body weight 116 lbs, height 67 inches and body mass index (BMI) 18.2,  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 concurrent conditions included body mass index low. The subject's concomitant medications included Prenatal (unspecified vitamins) plus docosahexaenoic acid (DHA) for pregnancy.  The subject's obstetrical history included four previous pregnancies with one full-term live birth, one elective abortion, one spontaneous abortion and one stillbirth. The subject had no history of offspring with major congenital malformation (MCM). The subject had no paternal history with MCM, while maternal history with MCM included Down Syndrome in second cousin. The subject did not use alcohol or illicit drugs but was using ten cigarettes per day during pregnancy.  The subject's last menstrual period (LMP) date was reported as 02-Jun-2020. The subject's estimated delivery date (EDD) was reported as 09-Mar-2021 and corrected estimated date of delivery (CEDD) was reported as 07-Mar-2021. The type of pregnancy was singleton.   On 03-Aug-2020, the ultrasound revealed no MCM.  On 07-Oct-2020, at approximately 18 weeks of gestation (calculated per LMP), the subject was vaccinated with Afluria QIV (Flu Vaccine Egg Split QIV CSL) (influenza vaccine, route of administration, anatomical location: not reported) (explicitly coded as 'Vaccine exposure during pregnancy') for an influenza immunisation. The batch number reported was P100253284.  On the same day, the ultrasound revealed no MCM.   On an unspecified date in 2020, unknown amount of time after receiving Afluria QIV, the subject developed low laying placenta.  The outcome of the event was not reported.  The reporter did not provide causality assessment.  The event of 'placenta previa' was considered to be medically significant by a Physician within Seqirus' Pharmacovigilance and Risk Management Department.  Company comment:The subject experienced placenta praevia on an unknown date after vaccination with the suspect product Afluria QIV. Reportedly, vaccination occurred during pregnancy at gestational age at approximately 18 weeks of gestation. Temporal relationship is implausible because location of the placenta is determined at implantation (approximately first 3 weeks of gestation). The subject's obstetrical history of four previous pregnancies with one full-term live birth, one elective abortion, one spontaneous abortion and one stillbirth, may have contributed to development of the event. Causal relationship between the suspect product and the event placenta praevia is assessed as not related due to biological and chronological implausibility. Exposure during pregnancy is assessed as not related per company conventions.; Sender's Comments: The subject experienced placenta praevia on an unknown date after vaccination with the suspect product Afluria QIV. Reportedly, vaccination occurred during pregnancy at gestational age at approximately 18 weeks of gestation. Temporal relationship is implausible because location of the placenta is determined at implantation (approximately first 3 weeks of gestation). The subject's obstetrical history of four previous pregnancies with one full-term live birth, one elective abortion, one spontaneous abortion and one stillbirth, may have contributed to development of the event. Causal relationship between the suspect product and the event placenta praevia is assessed as not related due to biological and chronological implausibility. Exposure during pregnancy is assessed as not related per company conventions.