The primary objectives of this study are:

In infants of women exposed to SPIKEVAX during pregnancy, to assess:

• If exposure to SPIKEVAX during pregnancy is associated with an increased birth prevalence of major congenital malformations (MCMs).
• If exposure to SPIKEVAX during pregnancy is associated with an increased birth prevalence of adverse neonatal and infant outcomes, specifically neonatal encephalopathy, small for gestational age, respiratory distress in the newborn, and incidence of hospitalization due to infections including coronavirus disease 2019 (COVID-19).
• In women exposed to SPIKEVAX during pregnancy, to assess whether exposure to SPIKEVAX is associated with an increased prevalence of hypertensive disorders [e.g., pre-eclampsia, eclampsia, and gestational hypertension] gestational diabetes, and post-partum hemorrhage; and
• To assess whether exposure to SPIKEVAX during pregnancy is associated with an increased incidence of stillbirth, preterm birth, and medically attended spontaneous abortion.

Inclusion Criteria:

• EOP within study period
• Continuous enrollment in a health plan contributing to the HealthCare Integrated Research Database℠ (HIRD) database for at least 90 days prior to the estimated LMP.

Exclusion Criteria:

• Exposure to any non-Moderna COVID-19 vaccines at any time prior to LMP and from LMP through the exposure ascertainment period for the outcome of interest. However, pregnant women exposed to other non-Moderna vaccines in addition to SPIKEVAX will be included in a sensitivity analysis.
• Instances where the outcome of a pregnancy is not documented (e.g., a prenatal care claim is followed by no further documentation of pregnancy, termination, or delivery where the participant remains enrolled in the health plan) may also be observed. The number of these possibly exposed pregnancies will be tabulated and described; however, they will not be included in the descriptive or comparative analyses.

Study population includes women for whom an LMP can be successfully calculated based on a non-missing end of pregnancy (EOP), and who also meet the eligibility criteria to be included in the study analyses.