INTERLEUKIN-1-BETA LEVELS IN HUMAN EMBRYO CULTURE SUPERNATANTS AND THEIR PREDICTIVE VALUE FOR PREGNANCY

Interleukin 1 (IL-1) is possibly one factor produced by the embryo tha t might have a role in the maternal immunological recognition of pregn ancy. The purpose of this study was to identify an embryo-related fact or suitable for prediction of pregnancy during IVF procedures. For thi s purpose, IL-1 beta levels were measured in 21 samples of human embry o culture-conditioned media. The average number of embryos per sample was 5 +/- 1. Simultaneously, 16 cell culture media containing 10% auto logous serum but no embryos were tested as controls. IL-1 beta levels were measured using the ELISA technique, and the biological activity o f IL-l was measured by means of a C3H/HeJ mice thymocyte proliferation assay. The average IL-1 beta level +/-S.E.M. was 49+/-7 pg/ml in embr yo culture-conditioned media and 12+/-2 pg/ml in controls (P < 0.001). The average IL-1 beta level in embryo culture-conditioned media from viable pregnancy cycles was 82+/-6 pg/ml (n = 8), while in those cases that did not result in viable pregnancies the IL-1 beta level was sig nificantly lower (28+/-4 pg/ml, n = 13, P < 0.001). The IL-1 activity of embryo culture-conditioned media, measured by [H-3]thymidine incorp oration in thymocytes was increased, compared with control media (442/-51 counts/min vs. 337+/-13 counts/min, P < 0.05), and the highest va lues corresponded to media containing those embryos that resulted in p regnancies (589+/-41 counts/min, P < 0.01 vs. controls). We conclude t hat the determination of the levels of this cytokine in embryo culture -conditioned media might be a predictive parameter for pregnancies in patients undergoing TVF-ET. (C) 1997 Elsevier Science Ireland Ltd.