Injectable seasonal influenza vaccines are inactivated trivalent or quadrivalent vaccines produced in anticipation of the expected circulating strains of seasonal influenza virus for the coming influenza season.
Data on seasonal and pandemic influenza infection suggest that pregnant women, especially those with pre-existing medical conditions and in the later stages of pregnancy, are at increased risk of influenza complications and are more likely to experience adverse fetal outcomes such as miscarriage or stillbirth. Data regarding the risk of congenital malformation following maternal influenza infection during pregnancy are conflicting. Some studies have reported an association but a causal link to maternal fever rather than a direct effect of the influenza virus on the fetus has been proposed.
There is no indication that exposure to inactivated influenza vaccines in pregnancy is associated with an increased risk of adverse fetal effects. Additionally, there is evidence that seasonal influenza vaccination during pregnancy confers immunity to influenza in the neonate.
The UK Health Security Agency (UKHSA) recommends that all pregnant women, regardless of stage of pregnancy, should be offered the seasonal influenza vaccine due to the increased risk of morbidity and mortality associated with influenza infection during pregnancy.
There are no known adverse fetal effects of maternal influenza vaccination in pregnancy. However, other risk factors may be present in individual cases which may independently increase the risk of adverse pregnancy outcome. Clinicians are reminded of the importance of consideration of such factors when performing case-specific risk assessments.
This is a summary of the full UKTIS monograph for health care professionals and should not be used in isolation. The full UKTIS monograph and access to any hyperlinked related documents is available to NHS health care professionals who are logged in.
If you have a patient with exposure to a drug or chemical and require assistance in making a patient-specific risk assessment, please telephone UKTIS on 0344 892 0909 to discuss the case with a teratology specialist.
If you would like to report a pregnancy to UKTIS please click here to download our pregnancy reporting form. Please encourage all women to complete an online reporting form.