Pregnancy-associated Plasma Protein-a Physiological Role In Follicular Development

Objective To study mechanism of pregnancy-associated plasma protein-A(PAPP-A) acting on follicular development and relationship between PAPP-A and in vitro fertilization -embryo transfer(IVF-ET) . Methods Human luteinized granulosa cells were isolated from follicular fluid obtained during oocyte retrieval of IVF-ET program and were cultured with M199 media plus various concentration of follicle stimulating hormone (FSH, 0% 0.5% 5% 10% 25% 50) or human chorionic gonadotropin(hCG, 0% 5% 10% 50% 75% 100IU/ml). The media were collected and PAPP-A in the media were measured by time-resolved fluoroimmunoassay. The levels of PAPP-A in follicle fluid(FF) of 70 patient were measured by time-resolved fluoroimmunoassay. Relation between PAPP-A levels in follicular fluid(FF) and pregnancy outcome and somes factors which influence the outcome were analyzed. Result FSH 0.5-25IU/ml, hCG 5-100IU/ml caused higher levels of PAPP-A in the media compared with the control (P<0.05) and there were not any significant difference in PAPP-A production stimulated by various dose of FSH or hCG. But when FSH was 50IU/ml, PAPP-A production was not significantly changed compared with the control. PAPP-A levels in FF was positively correlated with the numbers of retrivaled oovytes. When FF PAPP-A levels were 800IU/L or more, rate of fertilization, cleavage, good quality embryo and pregnancy was higher . FF PAPP-A levels were found to be significantly higher in fertilization group and pregnancy group. Compared with FSH 300IU, FF PAPP-A levels were higher when original dose of FSH was 150-225IU, but it was not significant. FF PAPP-A levels were not different when patients were treated with hCG 5000IU or 10000IU before oovyte retrival. Conclusion PAPP-A may involve in the mechanism of FSH and LH acting on follicular development. PAPP-A in FF is associated with IVF-ET outcome and some factors which influence the outcome.