IVF may raise risk of certain disorders in babies — and epigenetic ‘signatures’ in the placenta could explain why

Assisted Reproductive Technologies and the Epigenetics of IVF

Assisted reproductive technologies (ART), such as in vitro fertilization (IVF), have revolutionized the field of fertility treatments. Over the years, ART has helped usher in more than 10 million successful births worldwide, making it a remarkably safe and effective approach for couples dealing with fertility issues. However, these technologies come with some increased risks, particularly concerning epigenetic modifications and their potential effects on the health of children conceived through ART.

Studies have shown that the use of IVF and other ART methods can slightly raise the risk of certain health impacts for babies. These involve reduced birth weight, certain cardiovascular and metabolic disorders, and a lower risk of heart defects. The reason for these subtle changes lies in how ART procedures alter gene activity, often more significantly in fresh embryos compared to frozen ones. Fresh embryos are exposed to hormones at critical points in development, leading to changes in gene expression and potentially affecting placental size and newborn growth.

In a groundbreaking study published recently, researchers analyzed DNA and epigenetic markers in placental tissues from IVF-conceived pregnancies. Their findings revealed that ART procedures, particularly those involving fresh embryos, result in significant gene alterations. Some of these alterations are linked to male fertility problems, such as those often associated with intracytoplamic sperm injection (ICSI). ICSI, while considered a type of IVF, involves the direct injection of a single sperm into an egg, which is frequently used when the male partner has known fertility issues.

Genes like TRIM28 and DLK1 play crucial roles in embryo implantation, epigenetic regulation, and placental formation. Changes in these genes can explain some of the subtle epigenetic changes observed in ART-conceived newborns. For instance, TRIM28 regulates epigenetic markers essential for embryo implantation, while DLK1 is linked to infertility, low birth weight, and placental growth. Together with NOTCH3, they form blood vessels critical for placental formation and embryonic development.

Despite the subtle differences found in gene activity, researchers emphasize that most ART-conceived children are generally healthy. However, they do face small increased risks of heart defects, preterm birth, low birth weight, and so-called imprinting disorders. These conditions are present at birth and can have widespread effects, although they remain relatively uncommon.

The field of ART continues to evolve, with ongoing research aimed at clarifying how specific genes affect fertility and fetal growth. By pinpointing these genes and their functions, scientists hope to provide better insights into the long-term effects of ART procedures and improve care for couples undergoing fertility treatment.

For now, ART remains a safe and effective option for achieving pregnancy. The scientific community’s ongoing efforts to understand the epigenetic implications of these technologies ensure that the journey to parenthood remains as safe as possible for both parents and their future children.