title: Does an abortion increase the risk of intrapartum infection in the following pregnancy?
abstract: Spontaneous and induced abortions have been suggested to increase the risk of intrapartum infection in the following pregnancy. We conducted a case-control study using data from the Washington State Birth Registry for the years 1989-1991. The study population comprised women delivering a singleton livebirth. A case was defined by the presence of intrapartum fever (N = 2,550). Controls (1:3) were selected from the remaining births (N = 7,326). We calculated Mantel-Haenszel summary odds ratios by stratified analysis. We evaluated the validity of intrapartum fever recorded on the birth certificate using data from an ongoing case-control study on clinical amnionitis in Washington State. We found intrapartum fever to be highly specific (0.98) and moderately sensitive (0.57) for a diagnosis of clinical amnionitis. We saw no increased risk of intrapartum fever after a fetal loss or termination when using women with no prior pregnancy as the reference group. On the other hand, we found a threefold elevated risk for both induced and spontaneous abortion when using women with a prior livebirth as the reference group. Our findings indicate that an abortion in a woman's first pregnancy does not have the same protective effect of lowering the risk for intrapartum infection in the following pregnancy as does a livebirth.
authors.affiliation: Department of Epidemiology, University of Washington, Seattle 98195, USA.
authors.forename: K
authors.initials: K
authors.lastname: Mühlemann
authors.forename: M
authors.initials: M
authors.lastname: Germain
authors.forename: M
authors.initials: M
authors.lastname: Krohn
mesh_terms: D000028:Abortion, Induced / Q000706:statistics & numerical data*; D000022:Abortion, Spontaneous / Q000453:epidemiology*; D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000453:epidemiology* / Q000209:etiology; D005500:Follow-Up Studies; D006801:Humans; D007231:Infant, Newborn; D011247:Pregnancy; D011645:Puerperal Infection / Q000453:epidemiology* / Q000209:etiology*; D012306:Risk