COVID-19 Vaccine Safety Surveillance in Early Pregnancy in the United States: Design Factors Affecting the Association Between Vaccine and Spontaneous Abortion

Details

• Alternative Title:
  Am J Epidemiol
• Personal Author:
  Vazquez-Benitez, Gabriela ; Haapala, Jacob L. ; Lipkind, Heather S. ; DeSilva, Malini B. ; Zhu, Jingyi ; Daley, Matthew F. ; Getahun, Darios ; Klein, Nicola P. ; Vesco, Kimberly K. ; Irving, Stephanie A. ; Nelson, Jennifer C. ; Williams, Joshua T. B. ; Hambidge, Simon J. ; Donahue, James ; Fuller, Candace C. ; Weintraub, Eric S. ; Olson, Christine ; Kharbanda, Elyse O.
• Description:
  In the Vaccine Safety Datalink (VSD), we previously reported no association between coronavirus disease 2019 (COVID-19) vaccination in early pregnancy and spontaneous abortion (SAB). The present study aims to understand how time since vaccine rollout or other methodological factors could affect results. Using a case-control design and generalized estimating equations, we estimated the odds ratios (ORs) of COVID-19 vaccination in the 28 days before a SAB or last date of the surveillance period (index date) in ongoing pregnancies and occurrence of SAB, across cumulative 4-week periods from December 2020 through June 2021. Using data from a single site, we evaluated alternative methodological approaches: increasing the exposure window to 42 days, modifying the index date from the last day to the midpoint of the surveillance period, and constructing a cohort design with a time-dependent exposure model. A protective effect (OR = 0.78, 95% confidence interval: 0.69, 0.89), observed with 3-cumulative periods ending March 8, 2021, was attenuated when surveillance extended to June 28, 2021 (OR = 1.02, 95% confidence interval: 0.96, 1.08). We observed a lower OR for a 42-day window compared with a 28-day window. The time-dependent model showed no association. Timing of the surveillance appears to be an important factor affecting the observed vaccine-SAB association.
• Subjects:
  Abortion, Spontaneous COVID-19 COVID-19 Vaccines Female Humans Pregnancy United States Vaccination
• Keywords:
  Case-control COVID-19 Vaccines Pregnancy Safety Spontaneous Abortion Study Design Surveillance
• Source:
  Am J Epidemiol. 192(8):1386-1395
• Pubmed ID:
  36928091
• Pubmed Central ID:
  PMC10466212
• Document Type:
  Journal Article
• Funding:
  CC999999/ImCDC/Intramural CDC HHSUnited States/ ; UL1 TR001863/TR/NCATS NIH HHSUnited States/
• Volume:
  192
• Issue:
  8
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha256:b9a8b7e1f1f924739cea45c83de44c33d6a00216318e976ca377eb79cbec3cd6
• Download URL:
  https://stacks.cdc.gov/view/cdc/132643/cdc_132643_DS1.pdf
• File Type:
  [PDF - 209.38 KB ]