Subchorionic haematoma; Migraines; Vaccine exposure during pregnancy; This is an observational study case, received on 27-Oct-2020 from other health professional, concerning a 26-year-old pregnant, female subject of body weight: 143.5 lbs, height: 62.8 inches and body mass index (BMI): 25.6, who was enrolled in a prospective observational safety study.   The subject's concurrent conditions included anxiety, morning sickness and increased body mass index.  The subject's past medications included Bonjesta (doxylamine succinate, pyridoxine hydrochloride) for morning sickness. The subject's concomitant medications included Prenatal + DHA (unspecified minerals and vitamins) for pregnancy and Diclegis (doxylamine succinate, pyridoxine hydrochloride) for morning sickness.  The subject's obstetrical history noted two previous pregnancies which included one full-term live birth and one spontaneous abortion. The subject had no history of offspring with major congenital malformation (MCM) and no 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 08-Jun-2020, the estimated delivery date (EDD) was 15-Mar-2021 and corrected estimated date of delivery (CEDD) was reported as 30-Mar-2021. The type of pregnancy was singleton.  On 12-Aug-2020, ultrasound revealed no MCMs.  On 02-Sep-2020, ultrasound, counsyl chromosomes 13, 18, 21, Sex chromosome analysis and counsyl fundamental panel with fragile X revealed no MCMs.  On 04-Sep-2020 and 08-Sep-2020, ultrasound revealed no MCMs.   On 08-Oct-2020, at gestational age of 17 weeks (calculated per LMP), the subject was vaccinated with Afluria QIV vaccine (Flu Vaccine Egg Split QIV CSL) (Influenza vaccine, dose, route of administration and anatomical location: not reported) (explicitly coded as 'Vaccine exposure during pregnancy') for influenza immunisation. The batch number reported was P100253284.  On an unknown date, an unknown time after vaccination, the pregnancy status was collected, and it was noted that the subject had subchorionic haematoma. The subject also experienced migraines.   At the time of initial reporting on 27-Oct-2020, the subject had not recovered from the event of migraines.  The outcome for the event of subchorionic haematoma was not reported.   The event of 'subchorionic haematoma' was considered serious due to criterion of medical significance by a Physician within Seqirus' Pharmacovigilance and Risk Management Department.  The reporter did not provide a causality assessment.  Company comment:A 26-year-old female pregnant subject developed subchorionic haematoma and migraine on an unknown date after vaccination with the suspect product Afluria QIV. Chronology is unclear. The subject's medical history of anxiety and increased body mass index may have contributed to development of the events. The subject's obstetrical history noted two previous pregnancies which included one full-term live birth and one spontaneous abortion. Subchorionic bleed is a common cause of first-trimester bleeding and often occurs in uncomplicated pregnancies. Women who have already had one baby or who are older appear to be more likely to develop subchorionic hematomas. With information presented, causality for both events is assessed as not related due to confounders provided. Causal relationship for vaccine exposure during pregnancy is assessed as not related per company conventions.; Sender's Comments: A 26-year-old female pregnant subject developed subchorionic haematoma and migraine on an unknown date after vaccination with the suspect product Afluria QIV. Chronology is unclear. The subject's medical history of anxiety and increased body mass index may have contributed to development of the events. The subject's obstetrical history noted two previous pregnancies which included one full-term live birth and one spontaneous abortion. Subchorionic bleed is a common cause of first-trimester bleeding and often occurs in uncomplicated pregnancies. Women who have already had one baby or who are older appear to be more likely to develop subchorionic hematomas. With information presented, causality for both events is assessed as not related due to confounders provided. Causal relationship for vaccine exposure during pregnancy is assessed as not related per company conventions.