Usual outpatient antenatal care consists of routine checking of the maternal and foetal health by either clinic midwives or obstetricians along with health education to promote a healthy pregnancy.

The intervention group will receive a brief 5 to 10-minute educational talk by research nurse explaining the facts of influenza and influenza vaccine and answering participant questions.

The intervention will include a brief 5 to 10-minute educational talk by research nurse explaining the facts of influenza and influenza vaccine and answering participant questions. The educational intervention will focus on: (1) Hong Kong government's recommendation regarding influenza vaccine during pregnancy, (2) potential complications associated with influenza during pregnancy and for young infants, (3) safety of influenza vaccine for mother and foetus, and (4) potential benefits of influenza vaccine for mother and infant, and (5) where and how to get the influenza vaccine in Hong Kong.

The proportion of influenza vaccination in the control and intervention groups

The influenza and influenza vaccine knowledge of participants in the control and intervention groups after receiving the intervention.