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

The objective of this study was to determine the urinary excretion of prostacyclin (PGI2) and thromboxane A2 (TXA2) 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. TXB2, 6-keto-PGF1 alpha 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-TXB2 and 2,3-dinor-6-keto-PGF1 alpha were lower before embryo transfer in women who achieved a pregnancy than in those who did not conceive (p < 0.05). Contrary to women who did not conceive, women who achieved pregnancy had an increase in 6-keto-PGF1 alpha excretion after embryo transfer (p = 0.04). In women who did not conceive, levels of 2,3-dinor-TXB2 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.