Positive Correlation of Oestradiol Level on Trigger Day with the Secretion Level of Endometrial Kisspeptin and Leukaemia Inhibitory Factor in the Mid-Luteal Stimulated Cycle

BACKGROUND: Kisspeptin plays a role in the oestradiol negative-feedback regulation of GnRH as well as gonadotropin. In addition, kisspeptin has been postulated to induce the production of an important cytokine called leukaemia inhibitory factor (LIF). AIMS: This study aims to investigate the correlation between varying oestradiol levels measured on trigger day of the ovarian stimulation and the mRNA expression level of endometrial kisspeptin and LIF. STUDY SETTING AND DESIGN: Prospective cross-sectional study took place in Morula IVF Jakarta clinic. MATERIALS AND METHODS: A total of 43 infertile couples underwent an in-vitro fertilization (IVF) program. Subjects were grouped based on oestradiol levels as follows: group A ([≧ 3000 pg/mL, n = 15], group B [2000–2999 pg/mL, n = 14], group C [<2000 pg/mL, n = 14]). STATISTICAL ANALYSIS USED: ANOVA test was utilised to compare the expression of kisspeptin and LIF among study groups while Pearson correlation was used to identify the correlation between variables. RESULTS: A significantly higher mRNA expression of both Kisspeptin and LIF was found in group A than in groups B and C (P < 0.001). The mRNA expression of kisspeptin and LIF correlated positively with the oestradiol level (r = 0.638, P < 0.001 and r = 0.634, P < 0.001, respectively). Moreover, a strong association between Kisspeptin and LIF expression was also detected (r = 0.700, P < 0.001). CONCLUSIONS: mRNA expression of kisspeptin and LIF was significantly different according to the oestradiol levels in the study groups. Increased oestradiol level was shown to elevate the expression of endometrial kisspeptin and LIF in women undergoing the IVF programme.