The rationale for the use of measles post-exposure prophylaxis in pregnant women: a review

A review of published literature was undertaken to investigate the maternal and fetal effects of measles infection in pregnancy and to inform the need for post-exposure prophylaxis. There is no evidence to support an association between measles in pregnancy and congenital defects. However, the need for effective post-exposure protection is supported by studies suggesting a high risk of severe maternal morbidity, fetal loss and prematurity. Measles in late pregnancy can also lead to perinatal infection in the infant, which may be associated with a high mortality and the risk of subacute sclerosing panencephalitis. UK guidance recommends using human normal immunoglobulin for susceptible pregnant women exposed to measles. Although there is no direct evidence that this will reduce the complications of measles in pregnancy, it may attenuate disease and therefore reduce the rate of complications. Measures to identify women likely to be susceptible include assessment of age, vaccination history, and/or antibody testing.

Protecting infants against measles in England and Wales: a review

OBJECTIVE

To establish the most appropriate age ranges for the use of human normal immunoglobulin and MMR vaccine as postexposure prophylaxis.

DESIGN

Review of literature and of laboratory confirmed measles cases.

SETTING

England and Wales and countries with a similar measles epidemiological profile.

PATIENTS

Women of childbearing age and infants.

MAIN OUTCOME MEASURES

The risk of measles, maternally derived measles antibody levels and the response to measles containing vaccines in infants.

RESULTS

By 4 to 5 months of age, only 28-45% of infants born to women from highly vaccinated populations have protective levels of measles antibody. In the postvaccine era, between 74% and 80% of infants vaccinated between 6 and 9 months respond to vaccine, and around 67% have clinical protection from measles vaccination.

CONCLUSION

This study suggests that many infants being born in the UK will become susceptible to measles before 6 months and will be able to respond to vaccine between 6 and 9 months of age. It is proposed that current guidance is changed to recommend passive immunisation with human normal immunoglobulin for most infants exposed to measles below 6 months of age. For infants aged 6 months or over exposed to measles, vaccination with MMR may be given.