A recent investigation has turned the spotlight on the placenta to better understand the effects of Assisted Reproductive Technology (ART) on child development.
The study discovered noteworthy differences in placentas resulting from both frozen and fresh embryo transfers, particularly emphasizing variations in a gene associated with obesity and type 2 diabetes.
Impact of Infertility and ART
Infertility impacts about one in six couples who are trying to conceive.
In Finland, over 5% of births each year rely on ART, contributing to a staggering global total of more than ten million children conceived through such advanced methods.
While children born through ART typically enjoy good health, they face a slightly higher risk of experiencing growth issues and certain long-term health complications, such as cardiovascular, metabolic, and neurodevelopmental disorders.
Experts are still navigating through the complexities of these risks, debating whether they arise from ART processes themselves or from pre-existing fertility challenges faced by parents.
Research Methodology and Findings
To unravel the biological mechanisms linked to these ART-related risks, a group of researchers from the University of Helsinki and Helsinki University Hospital examined both placentas and newborns from 80 ART pregnancies and 77 spontaneous ones.
This comprehensive study uniquely considered various ART techniques and the gender of the infants.
The placenta plays a crucial role in connecting mother and fetus, acting as a conduit for environmental factors while supporting fetal development.
Associate Professor Nina Kaminen-Ahola, who led the research, pointed out that studying the placenta can provide valuable insights into early developmental stages, which are usually difficult to observe in humans.
The research focused on gene activity within the placenta, particularly the significance of DNA methylation.
This crucial epigenetic marker plays a role in regulating how genes express themselves.
The team also delved into how these genetic changes connect to the weights and heights of both the placentas and the newborns.
One of the standout findings was the stark contrast between placentas from fresh versus frozen embryo transfers.
In fresh transfers, IVF embryos are placed directly into the uterus, while frozen transfers involve thawing embryos before implantation.
Past studies indicated that children and placentas from fresh transfers tend to be smaller, a conclusion reinforced by this research.
Notably, significant metabolic and growth-related differences emerged in placentas associated with fresh embryo transfers.
Significance of DLK1 Gene
Additionally, the research revealed alterations in the function of the DLK1 gene, which was shown to have lower expression levels in placentas from ART pregnancies as well as in those from subfertile parents who managed to conceive naturally after pursuing fertility treatments.
The DLK1 gene plays a pivotal role in metabolism and is connected to obesity and diabetes, as well as the adjustments mothers undergo during pregnancy.
Previous animal research has suggested that Dlk1 is essential for effective maternal energy management during pregnancy, enabling a transition in energy use from carbohydrates to fats to support fetal growth.
Notably, silencing this gene has been linked to reduced birth weights.
Kaminen-Ahola noted that similar trends have been recorded in human studies, particularly regarding the link between DLK1 and low birth weight.
However, the authors stressed the necessity for additional research to further clarify the gene’s role in subfertility and its association with the rising rates of metabolic disorders like obesity and type 2 diabetes.
Although these findings hold promise, the researchers acknowledge the need for more extensive sampling to deepen the understanding of how various ART methods, parental subfertility, and the gender of children affect their growth and overall health.
Long-term follow-up for these children is essential to evaluate the lasting impacts of ART.
Kaminen-Ahola expressed hope that the insights gained from this research could inform and refine ART practices, while also enhancing comprehension of the causes behind subfertility.
She also expressed gratitude to the families participating in the ongoing epiART study, acknowledging their invaluable contribution to this important field of research.
Source: ScienceDaily