Single umbilical artery; Foetal exposure during pregnancy; This is an observational study case, initially received on 16-Dec-2019 with additional information received on 19-Dec-2019, (being processed together) concerning a foetal subject. The subject's mother was 32-year-old pregnant female, of body weight: 154 lbs, height: 59 inches and body mass index (BMI): 31.1, who was enrolled in a prospective observational safety study during pregnancy.  The subject's mother current condition included high BMI, post-traumatic stress disorder and insomnia.  The subject's mother concomitant medications included Prenatal vitamins (unspecified vitamins and minerals) for pregnancy and Vistaril (hydroxyzine embonate) for insomnia.   The subject's mother had one previous pregnancy with full term live birth outcome. 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 MCM. The subject's mother did not use tobacco, alcohol or illicit drugs during pregnancy. Paternal age was not provided.  The subject's mother's last menstrual period (LMP) was on 07-Jul-2019. Type of pregnancy was singleton and was complicated with polycystic ovary syndrome. The estimated date of delivery (EDD) was reported as 13-Mar-2019, corrected EDD (CEDD) was not reported.   On 19-Sep-2019, the subject's mother underwent nuchal translucency scan and first sequential screen, and no MCM was noted.   On 17-Oct-2019, the subject's mother underwent second sequential screen, and no MCM was noted.   On 11-Nov-2019, the subject's mother underwent to targeted ultrasound, and no MCM was noted.  On 17-Oct-2019, at approximately 18 weeks of gestation, the subject's mother was administered Afluria Quadrivalent [influenza vaccine, batch number: P100112488, dose, route of administration, anatomical location and expiration date: not reported] (explicitly coded as Foetal exposure during pregnancy') for an influenza immunization.   On unspecified date the single umbilical artery was noted as pregnancy complication.   At the time of initial reporting, the outcome of single umbilical artery not reported.   The event of single umbilical artery was assessed as serious due to medically significance per the company.  The causality assessment was not provided.  This case is linked to the case 201907353, mother case.  Company comment: Reportedly, single umbilical artery was associated with Afluria Quadrivalent. Vaccine was administered at 18 weeks of gestation. On unspecified date the single umbilical artery was noted as pregnancy complication, although the subject's mother underwent to ultrasound before and after vaccine administration, and no MCM was noted. Chronology is unclear. Causality was confounded by mother's medical history of high BMI. Causal role of the suspect vaccine cannot be excluded and is assessed as unlikely related. Foetal exposure during pregnancy is assessed as unrelated per company's conventions.; Sender's Comments: Reportedly, single umbilical artery was associated with Afluria Quadrivalent. Vaccine was administered at 18 weeks of gestation. On unspecified date the single umbilical artery was noted as pregnancy complication, although the subject's mother underwent to ultrasound before and after vaccine administration, and no MCM was noted. Chronology is unclear. Causality was confounded by mother's medical history of high BMI. Causal role of the suspect vaccine cannot be excluded and is assessed as unlikely related. Foetal exposure during pregnancy is assessed as unrelated per company's conventions.