Pharmacogenetic effect of β2AR genotype on preterm labor and response to tocolysis: a systematic review: A-693

Pharmacogenetic effect of b2AR genotype on preterm labor and response to tocolysis: a systematic review L. Stephenson1, R. Smiley1, M. Wood1, R. Landau1,2 1Department of Anesthesiology, Columbia University College of Physicians and Surgeons, New York, NY, USA; 2Department of Anesthesiology, University Hospital of Geneva, Switzerland Background and Goal of Study: The b2-adrenergic receptor (b2AR) displays genetic variability with several single nucleotide polymorphisms (SNPs). At codon 16 (Arg16Gly), the Arg allele is associated with decreased down-regulation of the b2AR; at codon 27 (Gln27Glu), the Glu allele decreases desensitization and down-regulation1. Since the b2AR is expressed in uterine muscle and is a target for tocolytic agents, it has been postulated that SNPs of b2AR could alter the course of preterm labor (PTL) and delivery (PTD). The goal of this systematic review of the literature was to analyze the current evidence regarding the b2AR genotype as it pertains to PTL and PTD. Materials and Methods: We searched MEDLINE (1966 to 2005) using the following search terms: preterm labor, pregnancy, tocolysis, b2 adrenergic receptor, polymorphism, genetic. We found 4 studies assessing the effect of b2AR genotype on outcome of PTL: 3 case-control studies3–5 and one prospective cohort treatment trial with b2-agonists for tocolysis2. Results and Discussions: In all four studies, b2AR genotype affected the course of PTL. In the study assessing the response to tocolysis2, neonatal outcomes were also significantly altered by genotype (Table).