Prostanoid excretion before in vitro fertilization relates to the likelihood of pregnancy

Abstract The objective of this study was to determine the urinary excretion of prostacyclin (PGI 2 ) and thromboxane A 2 (TXA 2 ) metabolites during in vitro fertilization (IVF) in relation to the clinical outcome of IVF. Urine was obtained overnight every 3 to 4 days from 24 women during IVF cycles. TXB 2 , 6-keto-PGF 1α and their 2,3-dinor derivatives were measured by high-pressure liquid chromatography with radioimmunoassay. The patients were women with ( n = 16, 119 samples) and without ( n = 8, 53 samples) a clinical IVF pregnancy. Concentrations of 2,3-dinor-TXB 2 and 2,3-dinor-6-keto-PGF 1α were lower before embryo transfer in women who achieved a pregnancy than in those who did not conceive ( p 1α excretion after embryo transfer ( p = 0.04). In women who did not conceive, levels of 2,3-dinor-TXB 2 were higher before embryo transfer than after transfer ( p = 0.04) and than levels in women who did conceive ( p = 0.01). We concluded that differences in urinary prostanoid metabolite excretion before embryo transfer appear to relate to the likelihood of pregnancy, but the nature of this relationship remains elusive.