Volatilomics as an Emerging Strategy to Determine Potential Biomarkers of Female Infertility: A Pilot Study

Abstract

Due to its high prevalence, infertility has become a prominent public health issue, posing a significant challenge to modern reproductive medicine. Some clinical conditions that lead to female infertility include polycystic ovary syndrome (PCOS), endometriosis, and premature ovarian failure (POF). Follicular fluid (FF) is the biological matrix that has the most contact with the oocyte and can, therefore, be used as a predictor of its quality. Volatilomics has emerged as a non-invasive, straightforward, affordable, and simple method for characterizing various diseases and determining the effectiveness of their current therapies. In order to find potential biomarkers of infertility, this study set out to determine the volatomic pattern of the follicular fluid from patients with PCOS, endometriosis, and POF. The chromatographic data integration was performed through solid-phase microextraction (SPME), followed by gas chromatography-mass spectrometry (GC-MS). The findings pointed to specific metabolite patterns as potential biomarkers for the studied diseases. These open the door for further research into the relevant metabolomic pathways to enhance infertility knowledge and diagnostic tools. An extended investigation may, however, produce a new mechanistic understanding of the pathophysiology of the diseases.

Keywords: endometriosis; follicular fluid; gas chromatography–mass spectrometry; infertility; polycystic ovary syndrome; premature ovarian failure; solid-phase microextraction; volatile organic compounds.

Figure 1

Schematic representation of VOC extraction from FF: (1) SPME syringe; (2) vial with 2 mL of FF; (3) heating mantle with magnetic stirrer. Created using BioRender.com.

Figure 2

Heatmap of the correlation and tendencies between the FFs of the four medical conditions and respective VOCs. The abscises correspond to: (C) controls; (POF) premature ovarian failure; (E) endometriosis; (PCOS) polycystic ovary syndrome. The coordinates represent the VOCs considered, which were assigned numbers. They were separated into six groups according to their distribution throughout the samples. Each number corresponded to a single VOC: (1) palmitic acid; (3) tetradecanal; (4) 2,4-di-tert-butylphenol; (5) diethyl phthalate; (7) 1,2,3,4-tetramethylbenzene; (8) 4-methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene; (9) palmitic acid ME; (13) isopropyl myristate; (14) octadecanal; (16) tetradecamethylcycloheptasiloxane; (17) hexadecanal; (18) gamma-stearolactone; (19) dodecane; (20) dodecamethylcyclohexasiloxane; (21) hexadecyloxirane; (22) octadecane; (23) diisooctylphthalate; (25) 1,2,3,5-tetramethylbenzene; (28) stearyl alcohol; (30) stearic acid; (31) tetradecamethylhexasiloxane; (32) hexadecamethylheptasiloxane; (34) eicosamethyl-cyclodecasiloxane; (35) octadecan-1-ol trimethylsilvyethe; (39) cyclotetradecane; (40) hexadecanoic acid; (41) methyl stearate; (43) heptadecane; (47) butyl-2-methylpropylphthalate; (49) ethyl xylene; (55) tetracosamethyl-cyclododecasiloxane; (56) docosane; (57) hexamethyldisiloxane; (58) 1,3-di-tert-butylbenzene; (60) 1-dodecanol; (67) oleamide; (71) 4,6-dimethyldodecane.

Figure 3

Percentual occurrence of VOCs in all the samples for each medical condition. The abscises correspond to: (C) controls; (POF) premature ovarian failure; (E) endometriosis; (PCOS) polycystic ovary syndrome. The coordinates represent the VOCs considered, which were assigned numbers: (1) palmitic acid; (3) tetradecanal; (4) 2,4-di-tert-butylphenol; (5) diethyl phthalate; (7) 1,2,3,4-tetramethylbenzene; (8) 4-methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene; (9) palmitic acid ME; (13) isopropyl myristate; (14) octadecanal; (16) tetradecamethylcycloheptasiloxane; (17) hexadecanal; (18) gam-ma-stearolactone; (19) dodecane; (20) dodecamethylcyclohexasiloxane; (21) hexadecyloxirane; (22) octadecane; (23) diisooctylphthalate; (25) 1,2,3,5-tetramethylbenzene; (28) stearyl alcohol; (30) stearic acid; (31) tetradecamethylhexasiloxane; (32) hexadecamethylheptasiloxane; (34) eicosamethyl-cyclodecasiloxane; (35) octadecan-1-ol trimethylsilvyethe; (39) cyclotetradecane; (40) hexadecanoic acid; (41) methyl stearate; (43) heptadecane; (47) bu-tyl-2-methylpropylphthalate; (49) ethyl xylene; (55) tetracosamethyl-cyclododecasiloxane; (56) docosane; (57) hexamethyldisiloxane; (58) 1,3-di-tert-butylbenzene; (60) 1-dodecanol; (67) oleamide; (71) 4,6-dimethyldodecane.