According to Statistics Canada, 27% of Canadian women are considered overweight. It has been known for some time that being overweight is linked to infertility, and women with a BMI higher than 30kg/m2 will likely take longer to conceive, if at all. The most common explanation for this is likely hormonal imbalance, which ultimately leads to ovulation problems. Unfortunately, this cause of infertility burdens many women with guilt on top of the already difficult emotional strain of being overweight and trying to conceive.
Poor IVF success rate linked with being overweight/obese
In some studies, being overweight or obesity was shown to significantly reduce the success of assisted reproductive technologies, such as IVF. This is generally caused by reduced egg(oocyte) numbers, poor response to ovarian stimulation, decreased fertilization rates, and increased miscarriage rates. In fact, some IVF clinics refuse their services to overweight and obese patients until they reduce their BMI.
What is the science behind this?
Looking deeper into why being overweight makes it difficult to conceive, a research group recently found a connection between maternal weight and mitochondrial damage in her eggs. Mitochondria are the cellular powerhouses responsible for generating energy, and we inherit them all from our mothers. Proper mitochondrial function is absolutely vital to the healthy development of the mother’s eggs and subsequently the embryo. However, when studying overweight pregnancies in mice, researchers report significant mitochondrial dysfunction in the eggs of overweight mothers, offering an explanation for overweight women who have difficulties conceiving. This was later confirmed in another similar study, where overweight mice produced eggs with significantly higher levels of genetic markers related to cellular stress and dysfunctional mitochondria when compared to the eggs of regular mice .
What does this mean for me?
The results of these studies in overweight mice shed light on the link between weight and infertility, providing an exciting new avenue of treatment for overweight women trying to conceive. Robker and colleagues successfully reversed the pregnancy complications they observed in their overweight mice (including the mitochondrial damage) by treating them with a cellular stress inhibitor called BGP-15, which is currently in early clinical trials for diabetes treatment. This study has tremendous implications in IVF. Individual genetics can now be profiled using services like GeneYouIn’s PregnaSeqTM, and genetic markers of increased cellular stress as a result of the mother’s weight can be easily identified. Appropriate steps can then be taken to increase the chances of a healthy conception/pregnancy for couples who might not otherwise be able to.
If you would like more information about obesity, please refer to our blog post about the relationship between genetics and obesity. As always, please share this article with your friends and family if you’ve found it to be useful, and make sure to follow GeneYouIn on Facebook and Twitter, or register for our newsletter to stay up to date on all the latest research in personalized medicine!
- Pandey, S., et al., The impact of female obesity on the outcome of fertility treatment. J Hum Reprod Sci, 2010. 3(2): p. 62-7.
- Grindler, N.M. and K.H. Moley, Maternal obesity, infertility and mitochondrial dysfunction: potential mechanisms emerging from mouse model systems. Mol Hum Reprod, 2013. 19(8): p. 486-94.
- Wu, L.L., et al., Mitochondrial dysfunction in oocytes of obese mothers: transmission to offspring and reversal by pharmacological endoplasmic reticulum stress inhibitors. Development, 2015. 142(4): p. 681-91.