Initial unsolicited pregnancy report received from the literature on 06 Jul 2017. This case is linked to 2017SA126988_ (same literature). The following is the verbatim from the article: Many countries recommend combined tetanus toxoid, reduced diphtheria toxoid and acellular pertussis immunization (Tdap) during pregnancy to stimulate transplacental transmission of pertussis antibodies to newborns. The immune system can be altered during pregnancy, potentially resulting in differing immunization risks in pregnant women. The safety of widespread Tdap immunization during pregnancy needs to be established. Our objective was to assess whether prenatal Tdap immunization was associated with adverse birth outcomes, and to evaluate the effect of timing of Tdap administration on these outcomes. We identified pregnancies at delivery in a large insurance claims database (2010-2014). Tdap immunization was categorized as optimal prenatal (27 + weeks), early prenatal (<27 weeks), postpartum (7 days post-delivery), or none. Medical claims were searched to identify maternal adverse immunization reactions (e.g. anaphylaxis, fever, Guillain-Barre syndrome [GBS]), adverse birth outcomes (e.g. preeclampsia/ eclampsia, premature rupture or membranes, chorioamnionitis) and newborn outcomes (e.g. respiratory distress, pulmonary hypertension, neonatal jaundice). Women with optimal or early prenatal Tdap were compared to those not immunized in pregnancy, using propensity score-weighted log-binomial regression and Cox proportional hazards models to estimate risk ratios (RR) and hazard ratios (HR). We identified 1,079,034 deliveries and 677,075 linked newborns; 11.5 percent were immunized optimally and 2.3 percent immunized early. There were 1 case of post-immunization anaphylaxis, and 12 cases of maternal encephalopathy (all post- delivery); there were no cases of GBS. Optimally-timed immunization was associated with small increased relative risks of: chorioamnionitis [RR = 1.11, (95 percent CI: 1.07-1.15), overall risk = 2.8 percent], and postpartum hemorrhage [RR = 1.23 (95 percent DI: 1.18-1.28), overall risk = 2.4 percent]; however, these relative increases corresponded to low absolute risk increases. Tdap was not associated with increased risk of any adverse newborn outcome. Overall, prenatal Tdap immunization was not associated with newborn adverse events, but potential associations with chorioamnionitis consistent with one previous study and postpartum hemorrhage require further investigation. This case involves a female patient (age not reported) who was vaccinated with a dose of INFLUENZA VACCINE, and a dose of TDAP (Batch number, expiry date, dose, dose in series, route, and site of administration were not reported for both doses) on an unknown date. While she was pregnant. (It was reported as the patient received Tdap during postpartum). The patient Pregnancy information (LMP, estimated delivery date, pregnancy trimester) were not reported. The patient medical history and concomitant medications were not reported. On an unknown date, two days after the vaccination with Tdap, and unspecified time frame after the influenza vaccine (also reported as follow-up length post-immunization), the patient developed Anaphylaxis. It was also a case of Vaccine exposure during pregnancy. The patient relevant lab tests and corrective treatment was not reported. The outcome of the event was not reported. Upon internal review the company decided to consider the event as serious due to important medical event Anaphylaxis. List of documents held by sender: none. Sender's Comments: Sanofi Company comment dated 11-Jul-2017: Patient experienced anaphylactic reaction following INFLUENZA VACCINE and DIPHTHERIA, TETANUS AND ACELLULAR PERTUSSIS VACCINE with unknown manufacturer. This poorly documented cases as time to onset is unknown. Additional information including but not limited to the patient's immunization history (i.e., previous immunizations and any adverse events following immunization), information regarding any drug or food intake during the period between vaccination and reaction and allergy testing to identify the culprit allergen are needed to further assess this case. Based on the available information, a role of the vaccine cannot be assessed.