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


Address reprint requests to Lukas Hefler, Department of Obstetrics and Gynecology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
E-mail: lukas.hefler@meduniwien.ac.at


Problem:  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.

Method of study:  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.

Results:  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.

Conclusions:  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.