Mycotoxins, Oocytes and the Endometrium: What the New Research Really Tells Us

Environmental fertility research often focuses on sperm because it is easier to collect and measure. A newer group of studies is now asking what aflatoxin exposure may do to the oocyte and to endometrial cells.

In 2026, researchers used metabolomic and proteomic methods to study changes in oocytes after aflatoxin B1 exposure. A separate study examined gene-network changes in bovine endometrial epithelial cells. These studies help us see possible mechanisms in more detail. Neither is a human IVF outcome trial.

What the new methods can show

Metabolomics measures small molecules involved in cellular activity, while proteomics examines proteins. Together they can reveal broad changes in energy use, oxidative balance and cell signalling. This is useful when an exposure appears capable of affecting several systems at once.

A large molecular dataset can also look more clinically conclusive than it is. Changes in an experimental pathway do not tell us a woman’s exposure level, the quality of her embryos or whether a particular intervention will improve pregnancy outcomes.

The oocyte question

Oocytes depend on carefully controlled energy metabolism and communication with the cells around them. Oxidative or mitochondrial disruption may affect maturation and developmental competence. The emerging research gives us a reason to continue investigating that possibility; it does not allow us to look backwards and declare that an exposure caused poor egg quality in one woman.

Age, ovarian reserve, stimulation response, metabolic health and laboratory factors remain part of the same assessment.

The endometrium question

The endometrium is an active tissue. It responds to hormones, immune signals, circulation and communication between cells. Experimental findings in bovine cells suggest that aflatoxin can alter networks involved in cell proliferation. This is not the same as proving that indoor mould caused a thin human endometrium or a failed implantation.

A donor egg addresses only one part of fertility

A donor egg may address the oocyte component of the fertility picture. The person receiving the embryo still contributes the endometrium, immune environment, circulation and wider health. If the lining repeatedly fails to develop or respond as expected, the receiving partner still needs a coherent investigation.

How I review the case

I build the chronology: the natural cycle before contraception, hormonal suppression, ovarian response, embryo information, lining measurements, response to medication, infection and inflammation history, metabolic markers, uterine assessment and any significant environmental change.

Exposure enters that history when the timeline creates a credible question. It should not be assumed from a thin lining, a failed transfer or a disappointing ovarian response alone. Both partners still need to be assessed as part of the complete fertility picture.

If egg development, implantation or endometrial response remains unexplained, you may first want to familiarise yourself with my methodology. You can then book an Introductory Fertility Review. We will separate what is known from what has been assumed and identify which unanswered questions deserve investigation before the next fertility decision.

This article is educational. Diagnosis and any prescribed treatment should be provided by a qualified medical professional.