From Petri Dish to Primitive Heart: How IVF Alters Early Cardiac Gene Networks and Epigenetic Landscapes

Numerous infants have been conceived by in vitro fertilization (IVF) and other assisted reproductive technologies (ART). Increasing evidence indicates that these approaches induce minor alterations in molecules during the initial phases of embryogenesis. This narrative review examines the molecular pathophysiology of embryonic cardiogenesis in the context of assisted reproductive technology, emphasizing transcriptional and epigenetic regulation. Essential transcription factors for cardiac development, including NKX2-5, GATA4, TBX5, ISL1, MEF2C, and HAND1/2, play a crucial role in mesodermal specification, heart tube formation, and chamber morphogenesis. Animal models and human preimplantation embryos have demonstrated that ART-related procedures, including gamete micromanipulation, supraphysiological hormone exposure, and extended in vitro culture, can alter the expression or epigenetic programming of these genes. Subsequent to ART, researchers have identified anomalous patterns of DNA methylation, alterations in histones, and modifications in chromatin accessibility in cardiogenic loci. These alterations indicate that errors occurred during the initial reprogramming process, potentially resulting in structural congenital heart abnormalities (CHDs) or modifications in cardiac function later in life. Analysis of the placental epigenome in babies conceived using assisted reproductive technology reveals that imprinted and developmental genes critical for cardiac development remain dysfunctional. This review proposes a mechanistic theory about the potential subtle alterations in the cardiogenic gene network induced by ART, synthesizing findings from molecular embryology, transcriptomics, and epigenomics. Understanding these molecular issues is crucial not only for enhancing ART protocols but also for evaluating the cardiovascular risk of children conceived by ART postnatally and for early intervention.