Maternal and Fetal Outcomes Following Influenza Vaccination in Pregnancy

Maternal and Fetal Outcomes Following Influenza Vaccination in Pregnancy

This is a nationwide cohort study to assess maternal and fetal outcomes following vaccination with a quadrivalent influenza vaccine (QIV) during pregnancy.

The Korean National Immunization Program (NIP) first introduced quadrivalent influenza immunization for all pregnant women in the 2020-2021 season. This nationwide cohort study is proposed to assess the risks of adverse maternal and fetal outcomes following vaccination with a quadrivalent influenza vaccine (QIV) during pregnancy. We will use the national health insurance database from the National Health Insurance Service (NHIS) linked with the national immunization program registry data from the Korea Centers for Diseases Control & Prevention (KCDC).

Inclusion Criteria:

• Pregnant women between September 22, 2020, and April 30, 2021.

Exclusion Criteria:

• Women aged <20 or >45 years
• Pregnancies with a chromosomal abnormality
• Pregnancies with exposure to a known teratogenic medication