Why we should consider epigenetic factors for IVF

 Research has demonstrated that children born through assisted reproductive technology (ART) are at a higher risk of preterm birth and associated morbidity.[1] So, why is? Well, the cause is likely to be multifactorial. There is the potential that IVF techniques could result in obstetric complications that negatively impact the child, or that ovarian stimulation may negatively impact placental development.[1] However, growing evidence suggests that parental characteristics play a crucial role.  

The opening night of the 26th Annual COGI Conference kicked off with a thought provoking exploration of this fascinating area of epigenetics, considering how parental factors can affect the health of an IVF child.  Epigenetics, the speakers explained, is inherently linked to the concept of developmental plasticity. Specific input during development can produce a lasting difference in phenotype.[2] As such, factors including fetal programming, metabolic endocrine disruption and structural change in organs can all significantly affect the birth of the child.

Effectively understanding how parental factors may affect future health outcomes could help us in the drive for increased precision medicine, where we can adapt specific treatments based on individual factors.

 

Caesarean Sections

 

Prof. Giancarlo Di Rienzo explained that IVF is associated with an increased use of Caesarean Section (CS) during birth. He showed that CS is in turn linked to increases in risk of:

-          Neonatal morbidity

-          Auto-immune diseases in the offspring

-          Metabolic disease in the offspring

 

Maternal Obesity and Smoking

 

Maternal obesity was highlighted as an important factor leading to higher risk of pre-term birth. Similarly, maternal smoking was shown to cause significant epigenetic changes. Interestingly, not only does smoking negatively affect the mother and the unborn child, but if the child is a female the smoke could also affect her reproductive cells. Therefore, these epigenetic changes could result in transgenerational negative effects. Indeed, Prof. Rienzo explained how increased risk of both pre-term birth and small for gestational age (SGA) infants has been shown to span multiple generations.

In his presentation, Prof. Nick Macklon also reiterated the role that diet and nutrition has in affecting epigenetic change.  

 

Could a Mediterranean Diet help?

 

Prof. Macklon explained that a Mediterranean diet is often recommended to women preparing for IVF. But is there really a benefit? To answer this question, he shared data assessing whether the diet has any significant positive impact on embryo quality and overall IVF success rate.

While there was some cohort evidence that the Mediterranean diet positively related to clinical pregnancy, Prof. Macklon explained that we must consider the important confounding factors including microbiome and genetics. He demonstrated that the positive impact of the diet, along with other advertised nutritionals on IVF outcomes is very slight, however this may have a greater cumulative effect over time.


Sources:

[1] A. Pinborg, U.B. Wennerholm, L.B. Romundstad, et al; Why do singletons conceived after assisted reproduction technology have adverse perinatal outcome? Systematic review and meta-analysis, Human Reproduction Update, Volume 19, Issue 2, 1 March 2013, Pages 87–104, https://doi.org/10.1093/humupd/dms044

[2] Nettle D, Bateson M. Adaptive developmental plasticity: what is it, how can we recognize it and when can it evolve?. Proc Biol Sci. 2015;282(1812):20151005.