This is a spontaneous case, initially received from other health professional on 10-Apr-2019, concerning a female neonate patient. The patient's mother did not have any history of offspring with major congenital malformation and had no maternal/paternal history with major congenital malformations. The patient's mother had no previous pregnancies. The patient's mother did not have a prior history of use of tobacco, alcohol or illicit drugs during pregnancy. The patient's mother's last lab report which included thyroid antibody test was normal. It was reported that the mother underwent thyroid antibody test every four weeks. The patient's mother's last menstrual period date was 21-May-2018. The patient's mother had singleton type of pregnancy. The patient's mother's current condition included increased thyroid antibodies (since 08-Jul-2018). The patient's mother's concomitant medication included levothyroxine for increased thyroid antibodies and Prenatal vitamins (ascorbic acid, calcium pantothenate, cyanocobalamin, ergocalciferol, nicotinamide, pyridoxine hydrochloride, retinol palmitate, riboflavin, thiamine mononitrate) for pregnancy. On 28-Jul-2018, the patient's mother underwent fibrosis mutation analysis and haemoglobin electrophoresis test and no major congenital malformation was noted. On 14-Aug-2018, the patient's mother underwent first trimester screening and no major congenital malformation was noted. On 30-Sep-2018, the patient's mother again underwent anatomical scan and no major congenital malformation was noted. On 06-Nov-2018, at approximately 24 weeks gestation, the foetus was exposed to AFLURIA QUADRIVALENT (batch number: YF41708, dose, route of administration, anatomical location and expiry date: not reported] (explicitly coded as foetal exposure during pregnancy) for an unknown indication. On 20-Dec-2018, the patient's mother underwent 1-hour glucose tolerance test and no major congenital malformation was noted. On 04-Jan-2019, the patient's mother underwent thyroid-stimulating hormone (TSH) test and no major congenital malformation was noted. On 22-Feb-2019, the patient's mother had undergone ultrasound scan and it showed moderate reduced fluid, foetal weight was less than 2 percent, small for gestational age (SGA). The umbilical doppler was normal. No major congenital malformation was noted. It was reported that, induction was performed on 36 weeks and 4 days. At approximately 36.6 weeks gestation, the patient's mother gave a live birth to a female neonate (premature baby) via urgent C-section (Caesarean) method. The characteristics of the neonate included birth weight: 2265 grams, head circumference: 30.5 cm, length: 47 cm and APGAR (appearance, pulse, grimace, activity, and respiration) scores were 4 at one minute and 9 at five minutes). The pregnancy complications included placental disruption and urgent caesarean section for concern of placental abruption. Heart rate was in 60s which was stimulated and positive pressure ventilation (PPV) was initiated which led to slow increase in heart rate to 100 after 2 minutes. The outcome of the events premature baby and low birth weight baby was not reported. The subject's expected date of delivery (EDD) was reported as 19-Mar-2019. This case is linked to 201805324 (the corresponding maternal pregnancy report). Reporter's Comments: A female neonate patient with mother's history (increased thyroid antibodies treated with levothyroxine and placenta abruption) was considered as premature baby, 3 months and 16 days after administration of AFLURIA QUADRIVALENT vaccine at 24 weeks of gestation (explicitly coded as foetal exposure during pregnancy). At approximately 36.6 weeks gestation, the patient's mother ultrasound indicated small for gestational age and gave a live birth to a female neonate (premature baby) via urgent C-section (Caesarean) method and was considered as low birth weight. Considering the risk factors (increased thyroid antibodies, co-administered levothyroxine and placenta abruption) and no evidence for a biological mechanism that could cause the events, the events (small for gestational age, premature baby and low birth weight) were assessed as not related to the suspect vaccine. The decision to administer a vaccine during pregnancy is related to medical decision making by the mother and her physician and is not related to any property of the medication. The event foetal exposure during pregnancy was assessed as not related considering the intended use of the vaccine. The company assessed the events (premature baby and low birth weight baby) as serious (medically significant).