Predictive value of serum and follicular fluid leptin concentrations during assisted reproductive cycles in normal women and in women with the polycystic ovarian syndrome

Leptin is an adipocyte-derived hormone which plays a central role in the re gulation of body weight and energy homeostasis and in signalling to the bra in that adequate energy stores are available for reproduction. Although lep tin may affect reproduction by regulating the hypothalamic-pituitary-gonada l axis, recent in-vitro observations indicate that leptin may also have dir ect intra-ovarian actions. Leptin concentrations were measured in women who succeeded in becoming pregnant within three cycles of in-vitro fertilizati on (IVF) or gamete intra-fallopian transfer (n = 53), in women who failed t o become pregnant within three cycles (n = 50), and in women with polycysti c ovarian syndrome (PCOS) (n = 22), It was found that lower follicular flui d leptin concentrations were a marker of assisted reproduction treatment su ccess in normal women. Women with PCOS had higher leptin concentrations tha n women without such a diagnosis, but this was due to their higher body mas s index (BMI). After adjustment for age and BMI, women with PCOS who became pregnant tended to have lower mean follicular fluid leptin concentrations than women with PCOS who did not succeed at becoming pregnant. Further stud ies exploiting the strengths of the IVF model are needed to assess whether the prognostic role for follicular fluid leptin in human reproduction is in dependent of other factors, and to elucidate the underlying mechanisms.