P-637 Different diffusion of Bisphenol-A from serum to follicular fluid in women undergone IVF cycles. EcoFoodFertility for Women Project
Authors: Gentile M , Chiusano M  L , Raimondo S , Gentile T , Cuomo F , Gentile R , Danza D , Iaccarino S , Fortunato A , Esposito A , Sosa Fernandez L  M , Piscopo M , Ferrara I , Lacatena R , Montano L 
Published: July 2024

Abstract

Study question
BisphenolA (BPA) is used as a raw material in the production of polycarbonate plastics and epoxy resins, today it is considered an endocrine disruptor.

Summary answer
BPA diffusion from serum to the follicular fluid is not homogenous in women both with regular menstruation or with pathologies of the reproductive system.

What is known already
It is well established that BPA is present in serum and urine of women who permanently live in areas with a high environmental impact.
Many studies report different diffusion of BPA in biological fluids, in fact, it is not clear how BPA bioaccumulates in tissues.
Despite the large number of animal experiments in this regard, there are few human studies on BPA levels in various body fluids, such as FF (Follicular fluid). Furthermore, there are few report in literature of BPA effects on the endocrine system, oocyte morphology and embryonic development.

Study design, size, duration
We enrolled 118 women underwent to a first IVF cycle to evaluate the diffusion of BPA between serum and Ff for a multicenter study. Group A, 49 women with regular menstruation and ovulation; Group B, 31 women with regular menstruation and ovulation but they took cortisone before the oocyte pick-up; Group C, 38 women of which 14 with ovarian endometriosis and 24 with PCOS. The age was homogeneous in the three groups, 28.7±4.1.

Participants/materials, setting, methods
We obtained serum and FF from women who underwent to IVF cycles, in the period between April 2017 and March 2019. BPA concentration was performed with ELISA enzyme immunoassay kit and the values are expressed in ng/mL. It was used 5 mL glass, BD Vacutainer® USP Type III, without silicon, red-capped, additive-free tubes and held horizontally. Follicular fluids were bloodless with negative albumin test.

Main results and the role of chance
In all samples examined (serum and FF) BPA was in different concentrations, the highest values were: 99,3 ng/mL in the serum and 85,2 ng/mL in the FF, while the lowest values in serum 42,5ng/mL and in FF 10,9 ng/mL.In group A, there is a significant diffusion of BPA from the serum to the FF (p &lt; 0.0001), with concentrations on average lower in the FF: BPA serum (ng/mL) 68,5±14,1, BPA FF(ng/mL) 42,4±12,8.
In group B, a higher BPA concentration emerged on average in the FF compared to the serum, maybe the diffusion is facilitated by the use of cortisone (p &lt; 0.005):BPA serum (ng/mL) 65,8±13,4, BPA FF(ng/mL) 74,3±9,2.
In Group C, it emerged that the concentrations of BPA in the FF were lower than in the serum, probably due to a greater resistance of the blood-follicular barrier to the passage of BPA (p &lt; 0.0001): BPA serum (ng/mL) 83,4±14,1, BPA FF(ng/mL) 38,7±19,2.

Limitations, reasons for caution
This study highlights the different mechanism of BPA diffusion in tissues. Further studies are needed to understand the reason for a lower diffusion of BPA in the FF in the presence of pathologies of the reproductive system. More data are needed to support the mechanisms of BPA bioaccumulation in FF.

Wider implications of the findings
From our data emerges that the use of cortisone in the period preceding the oocyte pick-up seems to promote the diffusion of BPA in the FF. We can hypothesize that this mechanism is also valid for other tissues and it could be one of many mechanisms of BPA bioaccumulation.

Trial registration number
001