While Preimplantation Genetic Testing (PGT) offers significant advantages in improving IVF outcomes and preventing genetic diseases, it's not universally adopted, and some individuals and clinics choose not to utilize it. Several factors contribute to this decision, ranging from ethical considerations to practical concerns.

One major reason is the cost. PGT adds a substantial expense to an already costly IVF cycle, making it financially inaccessible for some couples. Insurance coverage for PGT can be limited or non-existent, placing the full burden on the patients.

Another concern revolves around the invasiveness of the embryo biopsy. Although generally considered safe, some worry about potential harm to the embryo during the cell removal process, even if the risks are minimal. There's also the emotional toll of potentially discarding embryos identified as abnormal, which can be a difficult decision for many.

Furthermore, the accuracy of PGT is a point of debate. While highly accurate, PGT is not 100% perfect. The possibility of false positives (a healthy embryo incorrectly identified as abnormal) or false negatives (an abnormal embryo incorrectly identified as healthy) can lead to the discarding of viable embryos or the transfer of affected ones. This concern is particularly amplified by the phenomenon of mosaicism, where an embryo contains both normal and abnormal cells. Current PGT technology samples only a small portion of the trophectoderm, and this sample may not always perfectly represent the entire embryo's genetic makeup.

Finally, some clinics and patients believe that routine PGT-A for all IVF cycles may not significantly improve live birth rates in certain patient populations, especially younger women with good prognosis. They might argue that a natural selection process occurs, and many aneuploid embryos would not implant or would result in early miscarriage anyway. These varied perspectives highlight the complex decision-making process involved in fertility treatments.