Single umbilical artery; Foetal exposure during pregnancy; This is an observational study case, initially received from other health professional on 06-May-2020, concerning a foetal subject whose mother was 23-year-old, pregnant, female of body weight 176 lbs, height 63 inches and body mass index (BMI) 31.2, enrolled in a prospective observational safety study.   The subject's mother's current conditions included increased BMI, history of gestational diabetes mellitus and gestational hypertension with twins.  The subject's mother's concomitant medications included Prenatal vitamins (unspecified vitamins and minerals) for pregnancy.  The subject's mother's obstetrical history noted that the subject's mother had two previous pregnancies with two full term live births. The subject's mother had no maternal or paternal history with major congenital malformations (MCMs). The subject's mother had no history of offspring with MCMs. The subject's mother did not use tobacco, alcohol or illicit drugs during pregnancy.  The subject's mother's last menstrual period (LMP) date was 15-May-2019, the estimated delivery date (EDD) was reported as 19-Feb-2020, while the corrected estimated data of delivery (CEDD) was not provided. The type of pregnancy was singleton.  On 12-Aug-2019, the subject's mother underwent first sequential test and nuchal translucency screen. No MCMs were noted.  On 10-Sep-2019, the subject's mother underwent a second sequential test. No MCMs were noted.  On 10-Oct-2019, at approximately 21 weeks of gestation (calculated per LMP), the subject's mother was administered Afluria QIV (Flu Vaccine Egg Split QIV CSL) [influenza vaccine; batch number: P100112488, dose, anatomical location, route of administration and expiration date: not reported] (explicitly coded as Foetal exposure during pregnancy') for influenza immunisation.   On the same day, the subject's mother underwent a targeted ultrasound and no MCMs were noted.   On unspecified date, single umbilical artery (SUA) was noted. The subject's mother developed anaemia.  At gestational age of 39 weeks (as reported), the mother gave live birth to a male neonate by caesarean method of delivery. The neonate's birth weight was 3650 grams, body length and head circumference were not provided. The appearance, pulse, grimace, activity, and respiration (APGAR) scores were 8 at one minute and 9 at five minutes. APGAR score was not reported for 10 minutes. There was no MCMs identified at birth.  At the time of initial reporting, the outcome for the event of single umbilical artery' was not reported.  The event of single umbilical artery' was assessed as serious due to medical significance, per company.  The reporter did not provide causality assessment to Afluria QIV.  This case is linked to 202003305 (corresponding mother case).  Company comment: A foetal subject, whose mother was 23-year-old pregnant female,  developed single umbilical artery after vaccination with the suspect product Afluria Quadrivalent Afluria QIV for influenza immunisation. Reportedly, on unspecified date the event was detected. Chronology needs more clarification. The subject's mother's current conditions included increased BMI, history of gestational diabetes mellitus and gestational hypertension with twins. The subject's mother's concomitant medications included Prenatal vitamins (unspecified vitamins and minerals) for pregnancy. The subject's mother's obstetrical history noted that the subject's mother had two previous pregnancies with two full term live births. The subject's mother had no maternal or paternal history with major congenital malformations (MCMs). SUA has been associated with maternal smoking, diabetes, hypertension, and seizure disorders. With information presented, causality is assessed as not related to vaccine. Foetal exposure during pregnancy is assessed as unrelated per company conventions.; Sender's Comments: A foetal subject, whose mother was 23-year-old pregnant female,  developed single umbilical artery after vaccination with the suspect product Afluria Quadrivalent Afluria QIV for influenza immunisation. Reportedly, on unspecified date the event was detected. Chronology needs more clarification. The subject's mother's current conditions included increased BMI, history of gestational diabetes mellitus and gestational hypertension with twins. The subject's mother's concomitant medications included Prenatal vitamins (unspecified vitamins and minerals) for pregnancy. The subject's mother's obstetrical history noted that the subject's mother had two previous pregnancies with two full term live births. The subject's mother had no maternal or paternal history with major congenital malformations (MCMs). SUA has been associated with maternal smoking, diabetes, hypertension, and seizure disorders. With information presented, causality is assessed as not related to vaccine. Foetal exposure during pregnancy is assessed as unrelated per company conventions.