Breech presentation of twins/Twins breech; Elevated dopplers; Anemia; Vaccine exposure during pregnancy; This is a serious spontaneous case, initially received from other health professional on 16-Jul-2019, concerning a 29-year-old, adult female pregnant patient of height: 65 inches, weight: 224 pounds and body mass index: 37.3.  The patient's obstetrical history included 4 previous pregnancies which included 3 full term live births with no birth defects and one spontaneous abortion. The patient had no history of offspring with major congenital malformation. Also, the patient had no maternal or paternal history with major congenital malformations.   The patient's last menstrual period (LMP) date was 14-Jun-2018 and the type of pregnancy was multiple.   The patient had no prior history of use of tobacco, alcohol or illicit drugs during pregnancy. The patient's current condition included hypertension. The patient's concomitant medication included Prenatal vitamins [minerals NOS, vitamins NOS] for pregnancy (start date: 17-Sep-2018 and stop date: 02-Apr-2019). 0n 21-Mar-2018, the patient underwent ultrasound scan and no major congenital malformations were noted. On 17-Sep-2018, the patient underwent cystic fibrosis, spinal muscular atrophy and ultrasound scan and no major congenital malformations were noted.  On 01-Oct-2018, at gestational age of 15 weeks, the patient was administered Flucelvax QIVc (influenza vaccine, subunit influenza virus vaccine polyvalent, cell-culture-derived, batch number: 252664, dose, route of administration, anatomical location and expiry date: not reported) (explicitly coded as vaccine exposure during pregnancy) for an unknown indication.   On the same day, the patient underwent ultrasound scan and no major congenital malformations were noted. On 08-Nov-2018, the patient underwent ultrasound and Qnatal App (as reported), no major congenital malformations were noted.   On 01-Feb-2019, 4 months after administration of vaccine, the patient developed anaemia and was treated with ferrous sulphate (dose: 1 tablet, twice in a day, orally, from 01-Feb-2019 to 02-Apr-2019). On 07-Mar-2019, the patient underwent ultrasound and no major congenital malformations were noted.   On 02-Apr-2019, at gestational age of 37 weeks, the patient delivered twins by caesarean method which included one male and one female infant. The characteristics of male neonate included birth weight: 3090 grams, head circumference: 34.3 centimetres, body length: 49.5 centimetres, appearance, pulse, grimace, activity, and respiration (APGAR) scores were 8 at one minute and 9 at five minutes and characteristics of female neonate included birth weight: 2608 grams, head circumference: 33 centimetres, body length: 47 centimetres, appearance, pulse, grimace, activity, and respiration (APGAR) scores were 8 at one minute and five minutes. The subject's pregnancy complications included breech presentation of twins and elevated dopplers (doppler ultrasound abnormal). The twins had no major congenital malformations identified at birth.  The outcome of the event anemia was recovered on 02-Apr-2019. The outcome of the event breech presentation was not reported.  The patient's estimated date of delivery (EDD) and corrected estimated date of delivery (EDD) were reported as 23-Apr-2019.; Reporter's Comments: A 29-year-old female pregnant patient experienced anaemia, 4 months after receipt of Flucelvax QIVc (considered as vaccine exposure during pregnancy). The patient was diagnosed with breech presentation of twin pregnancy which required caesarean section method of delivery at 37 weeks of gestation. The pregnant state of the patient provide more plausible explanation rather than the suspect vaccine. Hence, causality of the event anaemia assessed as not related. Considering the implausible biological mechanism the event Breech presentation assessed as not related to suspect vaccine. The event vaccine exposure during pregnancy assessed as not related considering the intended use of the vaccine. The pregnancy complication is reported as elevated dopplers (Doppler ultrasound abnormal), unspecified period post vaccination. Despite lack of onset latency, the events appears to be the complication more due to twin pregnancy and current condition hypertension rather than suspect vaccine. Hence, causality assessed as not related. The case will be further assessed upon receipt of follow-up information. The company assessed the case as serious (medically significant).