Thrombocytopenia; Migraine; Nasal congestion; Vaccine exposure during pregnancy; This is an observational study case, initially received from other health professional on 20-Dec-2019, concerning a 27-year-old, female pregnant subject of body weight: 139 lbs, height: 64 inches and body mass index (BMI): 23.9 enrolled in a prospective observational safety study on pregnancy outcome in women immunized with Afluria QIV, a seasonal quadrivalent vaccine, during pregnancy.  The subject's current medical condition included anemia.  The subject's concomitant medications included Prenatal 19 (ascorbic acid, calcium carbonate, calcium pantothenate, colecalciferol, cyanocobalamin, ferrous fumarate, folic acid, nicotinamide, pyridoxine hydrochloride, retinol, riboflavin, thiamine hydrochloride, tocopheryl acetate, zinc oxide) as supplementation and ferrous sulfate for anemia.  The subject's obstetrical history noted that subject had no previous pregnancies. The subject had no history of offspring with major congenital malformation (MCM). The subject had no relevant maternal and paternal medical history. The subject did not use tobacco, illicit drug or alcohol during pregnancy.  The subject's last menstrual period (LMP) date was 14-Mar-2019. The subject's estimated delivery date (EDD) was 19-Dec-2019 and corrected estimated date of delivery (CEDD) was 21-Dec-2019. The type of pregnancy was singleton. The father's age was 30.  On 02-May-2019 and 13-May-2019, the subject underwent ultrasound and no MCM was noted.  On 06-Jun-2019, the subject underwent inheritest and ultrasound and no MCM was noted.  On 26-Jul-2019, the subject underwent ultrasound and no MCM was noted.  On 19-Sep-2019, at gestational age of 27 weeks, the subject was administered with Flu Vaccine Egg Split QIV CSL (Afluria QIV) [influenza vaccine; batch number: P100115154, dose, anatomical location, route of administration and expiration date: not reported] (explicitly coded as Vaccine exposure during pregnancy') for influenza immunisation.   On 02-Oct-2019, 13 days after vaccination, the subject developed nasal congestion and was treated with Flonase (mometasone furoate), one spray, once daily, orally, since 02-Oct-2019 and ongoing.  On 24-Oct-2019, the subject developed migraine and was treated with Tylenol (paracetamol), 550 mg, per need (prn), orally and with Fioricet (butalbital, caffeine, paracetamol), one capsule, every four hours prn, orally, both since 24-Oct-2019 and ongoing.  On 21-Nov-2019, the subject developed thrombocytopenia.   At the time of this report, the outcome of all events was not resolved.  Per company, the event of thrombocytopenia was assessed as serious due to criterion of medical significance.  The reporter did not provide causality assessment to Afluria (QIV).  Company comment: The subject experienced thrombocytopenia, migraine and nasal congestion after administration of Afluria QIV. The patient was administered vaccine at approximately 27 weeks of gestation. Chronology seems plausible. Causal role of the suspect vaccine cannot be excluded and is assessed as related for all events. Vaccine exposure during pregnancy is assessed as not related.; Sender's Comments: The subject experienced thrombocytopenia, migraine and nasal congestion after administration of Afluria QIV. The patient was administered vaccine at approximately 27 weeks of gestation. Chronology seems plausible. Causal role of the suspect vaccine cannot be excluded and is assessed as related for all events. Vaccine exposure during pregnancy is assessed as not related.