DOES AN ABORTION INCREASE THE RISK OF INTRAPARTUM INFECTION IN THE FOLLOWING PREGNANCY

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 Regis try for the years 1989-1991. The study population comprised women deli vering a singleton livebirth. A case was defined by the presence of in trapartum fever (N = 2,550). Controls (1:3) were selected from the rem aining births (N = 7,326). We calculated Mantel-Haenszel summary odds ratios by stratified analysis. We evaluated the validity of intrapartu m fever recorded on the birth certificate using data from an ongoing c ase-control study on clinical amnionitis in Washington State. We found intrapartum fever to be highly specific (0.98) and moderately sensiti ve (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 Drier pregnancy as the reference group. On the other ha nd, we found a threefold elevated risk for both induced and spontaneou s abortion when using women with a prior livebirth as the reference gr oup. Our findings indicate that an abortion in a woman's first pregnan cy does not have the same protective effect of lowering the risk for i ntrapartum infection in the following pregnancy as does a livebirth.