Preterm labour; Vaccine exposure during pregnancy; This is an observational study case initially received from other health professional on 10-Sep-2019, concerning a 25-year-old pregnant, female subject of body weight 179 lbs, height 64 in and body mass index (BMI) 30,7, enrolled in a prospective observational safety study on pregnancy outcomes in women immunized with seasonal cell culture influenza trivalent (TIVc) or quadrivalent (QIVc) vaccine during pregnancy.  The subject's obstetrical history noted that the subject had two previous pregnancies with two spontaneous abortions. The subject had no history of offspring with major congenital malformation. Also, the subject had no maternal or paternal history with major congenital malformations. The subject did not have a prior history of use of tobacco, alcohol or illicit drugs during pregnancy. The subject's medical history included depression. Concomitant medication included Prenatal vitamin (vitamin NOS, mineral NOS), clonazepam and Effexor XR (venlafaxine hydrochloride).  The subject's last menstrual period was on 23-Apr-2018 and estimated delivery date (EDD) and corrected estimated delivery date was reported as 28-Jan-2019. The type of pregnancy was singleton.   On 07-Jun-2018, the subject underwent ultrasound scan and no major congenital malformation was noted.  On 16-Aug-2018, the subject underwent ultrasound scan and quad screen and no major congenital malformation was noted.  On 17-Sep-2018, the subject underwent ultrasound scan and no major congenital malformation was noted.  On 08-Oct-2018, at gestational age of 24 weeks, the subject was administered Flucelvax QIVc [influenza vaccine, subunit influenza virus vaccine polyvalent, batch number: 252664, dose: 0.5 ml, expiration date, route of administration and anatomical location: not reported] (explicitly coded as 'vaccine exposure during pregnancy') for influenza immunisation.  On 06-Dec-2018, the subject underwent ultrasound scan and no major congenital malformation was noted.  At gestational age of 36.9 weeks [explicitly coded as 'premature labour'), the subject vaginally delivered female neonate. The neonate's birth weight was 3459 grams, head circumference was 33 cm and length was 50.8 cm. The appearance, pulse, grimace, activity and respiration (APGAR) scores were 8 (one minute) and 9 (five minutes), and no data was reported for APGAR score at ten minutes. No major congenital malformation was identified at birth.  This case is linked to 201904583, the corresponding child case.  Company comment: The patient was administered Flu Vaccine Cell Subunit QIV NVD at 24 weeks of gestational age (coded as vaccine exposure during pregnancy). The patient experienced premature labour (at gestational age of 36.9 weeks) 3 months after vaccination. Chronology seems plausible. The patient's medical history of two spontaneous abortions and concomitant use of clonazepam and Effexor XR confound causality. However, causal role of the suspect vaccine cannot be totally excluded and it is assessed as related. The event of vaccine exposure during pregnancy is assessed as unrelated per company's conventions.; Reporter's Comments: The patient was administered Flu Vaccine Cell Subunit QIV NVD at 24 weeks of gestational age (coded as vaccine exposure during pregnancy). The patient experienced premature labour (at gestational age of 36.9 weeks) 3 months after vaccination. Chronology seems plausible. The patient's medical history of two spontaneous abortions and concomitant use of clonazepam and Effexor XR confound causality. However, causal role of the suspect vaccine cannot be totally excluded and it is assessed as related. The event of vaccine exposure during pregnancy is assessed as unrelated per company's conventions.