Introduction Recent case studies following swine flu pandemic show that pregnant woman are more susceptible to flu infection. Various studies have sought to find an association between fetal congenital abnormalities (CAs) and maternal flu infection.

Methodology The authors performed a review of literature since 1950 in Medline and on the web using keywords ‘Flu’ and ‘CAs’ and collated the results.

Results In 2005, Acs et al1 compared 22 843 Hungarian newborns with CAs with 38 151 matched controls and showed a higher prevalence of maternal flu in newborns with cleft lip, central nervous system (CNS) and cardiac abnormalities. Risk was reduced by the use of antifever drugs.

A Finnish study in 1978 by Granroth2 compared 710 cases of CNS abnormalities with matched controls and concluded that CNS abnormalities were significantly associated with maternal flu infection.

Coffey and Jessop3 4, in two Irish studies in 1953 and 1955 involving 12 552 and 663 women respectively, showed that defects of CNS were more common in infants of women with flu.

An American study by Hardy et al5 looked at the 1957 flu epidemic and concluded that CAs were more common in women with flu infection.

However, no increase in the incidence of CAs was noted after any of the flu epidemics between 1957 and 1968 by Leck et al.6

Conclusion Antigenic shifts, reliance on clinical observation, discrepancies between serology and symptoms, variations in the geography and the ethnicity of the populations make it difficult to establish a distinct pattern between CAs and flu. However, there is substantial evidence liking maternal fever with CAs.