Higher follicular fluid (FF) levels of di(2-ethylhexyl) phthalate (DEHP) metabolites in indian women with poor ovarian reserve (POR)

While higher urinary levels of DEHP metabolites have been previously associated with a significant decrease in the antral follicle count (AFC) in women undergoing IVF (1), this study aimed to revalidate this in follicular fluid (FF). India is now witness to a trend where young women present a diminished ovarian reserve, low AMH values and have an early menopause. The role of Endocrine Disrupting Chemicals (EDCs) in these needs to be investigated. Since the oxidative metabolites do not form as a result of contamination during collection or storage they are considered more sensitive biomarkers of exposure to DEHP. The FF of women diagnosed with POR was screened for two oxidative metabolites of DEHP to establish the association with the disease etiology. A total of n = 58 Indian women (median age 33.5 years, range 26 - 42 years) seeking treatment for infertility and undergoing oocyte retrieval were included after consent. Of these, 30 with a serum AMH value < 2 ng/ml and an AFC < 6 were diagnosed with poor ovarian reserve [POR] and n = 28 women with a serum AMH value >2 ng/ml and an AFC > 6 were classified as having a good ovarian reserve. The study was approved by the Scientific Advisory Committee at Jaslok Hospital and Research Centre. The cryopreserved FF samples that were collected on the day of oocyte retrieval were processed using enzymatic deconjugation followed by the solid-phase extraction technique and analyzed by liquid chromatography tandem-mass spectrometry (LC-MS/MS) to detect the levels of two oxidative metabolites of DEHP - mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) and mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP). The overall median [range] level of MEOHP in the FF of 58 women was 3.6 [0.35-11.27] ng/ml. In women with POR, the median [range] of MEOHP was 4.1 [0.35-11.27] ng/ml while in those with a good ovarian reserve it was 1.7 [0.35-6.8] ng/ml. The overall median [range] of MEHHP in the FF of 58 women was 1.8 [0.14-13.02] ng/ml. In women with POR the median [range] was 2 [0.14-13.02] ng/ml relative to 1.7 [0.17-7.13] ng/ml in women with a good ovarian reserve. Neither difference was statistically significant [p values of 0.85 and 0.69 respectively]. This is a preliminary result of an ongoing larger Indian study. The median values of the DEHP metabolites are higher in the FF of women with POR though they do not reach statistical significance. A larger sample size may help support or refute the theory that higher levels of these metabolites in FF contribute to a diminished ovarian reserve.