Polymorphisms within the Interleukin‐1 Gene Family and Unexplained Late Intrauterine Fetal Death: A Multi‐center Study

Abstract

Interleukin-1 (IL-1) mediated inflammatory processes have been proposed to be involved in the pathogenesis of late unexplained intrauterine fetal death (IUFD). We determined whether common polymorphisms within the IL-1 gene locus can serve as candidate genes for this condition. In a multi-center case-control study, we evaluated the -889 C/T polymorphism of the IL-1alpha gene (IL1A), the -511 C/T polymorphism of the IL-1beta promoter (IL1B promoter), the +3953 C/T polymorphism of IL-1beta exon 5 (IL1B exon 5), and a 86 base pair repeat in intron 2 of the IL-1 receptor antagonist gene (IL1RN) in 94 women with IUFD and 94 healthy controls using pyrosequencing. No significant associations were found between the presence of polymorphic alleles of IL1A (P = 0.9), IL1B promoter (P = 0.3), IL1B exon 5 (P = 0.9), and IL1RN intron 2 (P = 0.7) and the incidence of IUFD. In women with IUFD, polymorphisms were not associated with the timing of fetal death and birth weight. Polymorphisms within the IL1 gene family are not associated with the occurrence of IUFD overall and do not modulate the clinical characteristics of affected pregnancies in a large series of Caucasian women.