1 Department of Economics and Business Economics - NCRR-National Centre for Register-based Research, Department of Economics and Business Economics, Aarhus BSS, Aarhus University2 Department of Biomedicine - Medical Microbiology and Immunology, Department of Biomedicine, Health, Aarhus University3 unknown4 Department of Economics and Business Economics, Aarhus BSS, Aarhus University5 Department of Biomedicine - Forskning og uddannelse, Øst, Department of Biomedicine, Health, Aarhus University6 SUND ph.d. skole7 School of Public Health, Faculty of Health Sciences, Aarhus University, Aarhus University8 Department of Economics and Business Economics, Aarhus BSS, Aarhus University9 Department of Biomedicine - Forskning og uddannelse, Øst, Department of Biomedicine, Health, Aarhus University
A Population-based Case-Control Study
Because parvovirus B19 infection during pregnancy has been associated with increased risk of fetal loss in small or selected study populations, the authors evaluated the risk in a population-based study. A nested case-control study was conducted by using a population-based screening for syphilis in 3 regions in Denmark from 1992 to 1994. Cases of women with fetal loss were identified in the National Patient Register (n = 2,918), and control women with live-born children were identified in the Medical Birth Register (n = 8,429) by matching on age and sampling week. First-trimester serum samples were tested for parvovirus B19 immunoglobulin M positivity. Parvovirus B19 immunoglobulin M positivity was associated with a 71% increased risk of fetal loss (odds ratio = 1.71, 95% confidence interval: 1.02, 2.86). Adjustment for number of children or stratifying for gestational age at loss did not change the risk estimate. Assuming causality, only 0.1% of fetal losses were attributable to parvovirus B19 positivity, a proportion which could increase to approximately 1% during epidemic periods. In conclusion, acute parvovirus B19 infection during the first trimester of pregnancy was associated with an increased risk of fetal loss. However, the impact on the overall burden of fetal losses appeared small even during epidemics.
American Journal of Epidemiology, 2012, Vol 176, Issue 9, p. 803-7