Lipidomic Components Alterations of Human Follicular Fluid Reveal the Relevance of Improving Clinical Outcomes in Women Using Progestin-Primed Ovarian Stimulation Compared to Short-Term Protocol

Abstract

BACKGROUND Increasing the success rate of in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) is a duty of clinicians that has made many seek a variety of protocols. This study was undertaken to use a liquid chromatography-mass spectrometry (LC-MS) to define the alterations of follicular fluid (FF) lipid metabolites in patients undergoing progestin-primed ovarian stimulation (PPOS) compared with short-term protocol, revealing potential correlations between the differentially expressed lipids and ameliorative clinical outcomes. MATERIAL AND METHODS Ninety-three infertile women undergoing IVF/ICSI treatment with PPOS (n=62) or a short-term protocol (n=31) were prospectively enrolled in a randomized controlled trial. FF samples were obtained from dominant follicles at the time of oocyte retrieval. Lipid metabolism profiles were analyzed using LC-MS. RESULTS Twelve lipids were found to be higher in patients treated with the PPOS protocol than in those receiving the short-term protocol, including triacylglycerols (TAG-34: 1+NH4, TAG-58: 0+NH4, TAG-64: 3+NH4, and TAG-64: 8+NH4), diacylglycerol DAG-38: 6+NH4, phosphatidylglycerols (PG-26: 0, PG-30: 2, and PG-40: 5), phosphatidylethanolamine PE-32: 2, lysophosphatidylethanolamine LPE-14: 1, lysophosphatidylinositol LPI-12: 0, and lysophosphatidylcholine LPC-16: 0. CONCLUSIONS Our data demonstrate that the PPOS protocol increases the levels of 12 lipids in FF, which reveals a strong association between the differentially elevated lipids and better IVF/ICSI outcomes.

Figure 1

The trends of serum hormones during ovarian stimulation in the PPOS and short-term protocols. E2 – estrogen; FSH – follicle-stimulating hormone; LH – luteinizing hormone; P – progesterone; PPOS – progestin-primed ovarian stimulation; MC3 – menstrual cycle day 3; MC10–12 – menstrual cycle day 10–12; (A) FSH (IU/L); (B) LH (IU/L); (C) E2 (ngl/L); (D). P (ng/L); n=6; * represent short-term protocol and PPOS protocols, and P<0.05.

Figure 2

Score plot of OPLS-DA analysis. OPLS-DA – orthogonal partial least square-discriminate analysis; PPOS – progestin-primed ovarian stimulation; A – Short-term protocol, B – PPOS (4 mg) protocol, C – PPOS (10 mg) protocol.

Figure 3

Differences in metabolite levels among 3 groups. DAG – diacylglycerol; LPC – lysophosphatidylcholine; LPE – lysophosphatidylethanolamine; LPI – lysophosphatidylinositol; PE – phosphatidylethanolamine; PG – phosphatidylglycerol; TAG – triacylglycerol; PPOS – progestin-primed ovarian stimulation; A – Short-term protocol, B – PPOS (4 mg) protocol, C – PPOS (10 mg) protocol.

Figure 4

Differentially expressed lipids in PPOS protocol. DAG – diacylglycerol; LPC – lysophosphatidylcholine; LPE – lysophosphatidylethanolamine; LPI – lysophosphatidylinositol; PE – phosphatidylethanolamine; PG – phosphatidylglycerol; TAG – triacylglycerol; PPOS – progestin-primed ovarian stimulation; (A) Heatmap of expression profiles for the 12 lipids that showed significant expression changes, green through red color indicates low to high expression level; A – short-term protocol, B – PPOS (4 mg) protocol, C – PPOS (10 mg) protocol; (B) Metabolite-associated correlation analysis, the highest correlation is 1 for the complete positive correlation, the correlation is a minimum of –1 for a complete negative correlation, and the blanks were statistically correlated with a P>0.05 and a color-coded portion of P<0.05.