PRENATAL COUNSELING

In fact, embryos that are of poor quality before biopsy—such as those found in women of advanced maternal age—may be more susceptible to the effects of biopsy. The outcome with such embryos may be of even greater detriment to the implantation rate (as discussed in regard to the Mastenbroek study earlier in this article).

The logic of performing PGS for aneuploidy in women of advanced maternal age was reasonable. But this group of women—in whom ovarian reserve is diminished, who respond poorly to ovulation induction, thereby limiting the total number of embryos for analysis and the poorer quality embryos possibly further impaired by the biopsy itself—represent the population that may be least amenable to PGS.

A further observation about PGS in women who have experienced recurrent pregnancy loss or IVF failure: Any impairment of embryos that is a consequence of the method of biopsy may further undermine the generally unsupportive results of PGS that have been documented in these patients.

Consensus on performing PGS

An assessment of European studies and practices reveals similar concerns voiced by the European Society for Human Reproduction and Embryology (ESHRE) PGD Consortium Steering Committee. The committee recently asserted a comparable opinion about “the insufficient data that demonstrate PGS is indeed a cost-effective alternative for standard IVF.”² Gleicher and colleagues, in their review of the literature, conclude that the indications for PGS are currently undefined and, as such, screening should be considered experimental.

Gleicher’s sentiments echo the recommendations of ASRM that, when PGS is considered,

• patients undergo counseling about its limitations, risk of error, and lack of evidence that it improves the live-birth rate
  
• available evidence does not support improvement in the live birth rate in women of advanced maternal age, who have failed previous implantation, who have experienced recurrent pregnancy loss, or who have experienced recurrent pregnancy loss specifically related to aneuploidy
  
• decisions about management should not be based on aneuploidy results of prior PGS cycles for a woman who has experienced recurrent implantation failure.