Uing data from a population based cohort in China, we will conduct retrospective cohort study to evaluate the risk of vaccine (e.g., HPV/influenza/rabies vaccine) administered during pregnancy (especially during first trimester) for adverse pregnancy outcomes (e.g., birth defects, preterm birth and low birth weight)

We will develop a vaccination cohort by linking population-based pregnancy registries (i.e., REPRESENT) with population-based vaccine databases.

The researchers will use data from this cohort to examine vaccine use 90 days before the last menstrual period and throughout pregnancy. This study will investigate whether maternal vaccination during pregnancy is associated with the risk of adverse pregnancy outcomes. Poisson regression based on propensity scores will be used to estimate the relative risk. To ensure the robustness of the results, the researchers will perform several sensitivity analyses and negative control analyses, such as the risk of adverse pregnancy outcomes in pregnant women who have been vaccinated several times and pregnant women who have been vaccinated in mid and late pregnancy as negative control groups.

Inclusion Criteria:

• All pregnant women in Xiamen who registry in our database.

Exclusion Criteria:

• Pregnant women who were lost to follow-up. Pregnant women exposed to related factors of known congenital malformation.

For women who are pregnant during the study period, the exposed population is pregnant women who have been vaccinated during the study period.

The datasets are not publicly available, but are available from the corresponding author on reasonable request.