Gestational age at outcome 35.6 weeks/ Premature birth; Foetal exposure during pregnancy; This is a serious spontaneous case reported by other health-professional and initially received on 31-May-2019, concerning a female neonate patient.  The patient's mother had one previous pregnancy with full term live birth. The patient's mother had no history of offspring with major congenital malformation. Also, the patient's mother had no maternal or paternal history with major congenital malformations. The patient's mother did not have a prior history of use of tobacco, alcohol or illicit drugs during pregnancy. The historical drug of the patient's mother included Aspirin (acetylsalicylic acid) for pre-eclampsia. The current condition of the patient's mother included addiction (unspecified). The patient's mother concomitant medications included Prenatal vitamins (minerals nos, vitamins nos) for pregnancy and Suboxone (buprenorphine hydrochloride, naloxone hydrochloride) for addiction treatment.   The patient's mother's last menstrual period (LMP) date was 07-Jul-2018. The type of pregnancy was singleton.  On 13-Nov-2018, at approximately 18 weeks of gestation, the patient was exposed to Flucelvax QIVc (influenza vaccine, subunit influenza virus vaccine polyvalent, cell-culture-derived, route of administration: transplacental, batch number: 252664, dose, parent's route of administration, expiry date and anatomical location: not reported) (explicitly coded as foetal exposure during pregnancy) for an unknown indication.  On 19-Nov-2018, the patient's mother underwent ultrasound scan, and no major congenital malformation was noted.  On an unspecified date (in third trimester of pregnancy), after vaccination, the patient's mother developed suspected placental insufficiency (reported as pregnancy complication). On an unspecified date, the patient's mother developed bacterial vaginitis and was treated with Metrogel gel (metronidazole, dose: 0.75 percent, route: vaginal, frequency: bid, from 19-Nov-2018 to 26-Nov-2018). On an unspecified date, the patient's mother developed urinary tract infection and was treated with Macrobid (clarithromycin) (dose: 1 unit, route: oral, frequency: bid, from 04-Jan-2019 to 11-Jan-2019).  On 18-Jan-2019, 24-Jan-2019, 31-Jan-2019 and 07-Feb-2019, the patient's mother underwent ultrasound scan, and no major congenital malformation was noted.  On 13-Mar-2019, at 35.6 weeks of gestational age, the patient's mother gave birth to a female infant (reported as preterm birth) by caesarean method of delivery. The characteristics of the neonate included birth weight: 3147 grams, head circumference: 34.3 cm, body length: 47.6 cm, appearance, pulse, grimace, activity, and respiration (APGAR) scores at one minute: 8, five minutes: 9 and ten minutes: no data was provided. The neonate had no major congenital malformations identified at birth.  The patient's mother's estimated date of delivery (EDD) was reported as 13-Apr-2019.  This case was linked to case 201903675 (the corresponding maternal pregnancy report).; Reporter's Comments: A female neonate patient experienced preterm birth at 35.6 weeks of gestation, 4 months after maternal receipt of Flucelvax QIVc (considered as foetal exposure during pregnancy). The maternal past obstetric history included pre-eclampsia and current gestational history included urinary tract infection and bacterial vaginosis. The patient's mother was suspected to have placental insufficiency in third trimester. Considering these underlying maternal gestational histories, which provide more plausible explanation of the event preterm birth, the company assessed causality as not related. The event foetal exposure during pregnancy assessed as not related considering the intended use of the vaccine. The company assessed the case as serious (medically significant).