This retrospective pregnancy case was reported in a literature article and described the occurrence of congenital hydrocele in a neonate. The mother received Tdap vaccine. The pregnancy resulted in a live neonate with a congenital anomaly. The neonate was diagnosed with congenital hydrocele. Serious criteria included GSK medically significant and congenital anomaly. Additional event(s) included maternal vaccine exposure. The outcome of congenital hydrocele was unknown. The outcome(s) of the additional event(s) included maternal vaccine exposure (unknown). The investigator considered that there was a reasonable possibility that the congenital hydrocele may have been caused by Tdap vaccine. Additional information was provided: This retrospective pregnancy case was reported in a literature article and it described the occurrence of a congenital hydrocele in a newborn infant of unspecified gender whose mother had received an unspecified Tdap vaccine (manufacturer unknown) during pregnancy. The patient's mother was between 12 and 45 years of age at the time of the vaccination. No information regarding her obstetric history, last menstrual period, expected date of delivery or gestation at the time of vaccination was provided apart from the authors commenting that women who had the vaccine within 3 days of the delivery had been excluded from the analysis. No further information on the patient's concurrent medical conditions, medical and family history or concomitant medication was provided. On an unspecified date between 1 May 2005 and 31 August 2009, the patient's mother received a dose of an unspecified Tdap vaccine (dosage unknown; administration route and site unspecified; batch number not provided). Please note that this vaccine was not recommended for pregnant women at the time and that the authors commented that the reason why most of the women had received it during this period was either for prophylaxis for open wounds/trauma or during routine health supervision. On an unspecified date between 1 May 2005 and 31 August 2009, at least 3 days after the vaccination, the patient was delivered (unspecified method) and subsequently diagnosed with a congenital hydrocele that was classified using code 7786 from the International Classification of Diseases (Ninth Revision). This was a serious case as the patient was diagnosed with a congenital anomaly. Treatment was unknown. Outcome was unknown at the time of reporting; although the authors mentioned that no infant had an International Classification of Diseases diagnosis code for pertussis in the year following birth. The authors did not comment on any causal relationship between the vaccine and this event. The authors concluded that "the results of this retrospective study are encouraging. However, prospective trials will be required to confirm the safety and efficacy of Tdap during pregnancy. Both trials have recruited small cohorts of healthy women in the third trimester (30-32 weeks) of pregnancy to further evaluate safety and immunogenicity of Tdap vaccine immunization in the mother and Tdap in the infant. The new universal recommendations for immunization of pregnant women during second and third trimester will afford further opportunity to collect prospective safety data on large cohorts of women". This case is 1 of the 5 valid cases reported in the same literature article.