Do you Day 5?  If not, your program is going to get left behind. Day 5 biopsy seems to have overtaken Day 3 PGD across most of the leading IVF centers in the US.  There were so many issues surrounding Day 3 biopsy, Day 5 seems to be a much better option.

Recently, trophectoderm biopsy is gaining popularity as an alternative method of embryo biopsy. Since trophectoderm cells are extra-embryonic tissue, they do not become part of the fetus but do become part of supporting structures, such as the placenta and membranes. Trophectoderm biopsy takes place at the blastocyst (day 5 or 6) stage of development, as the trophectoderm is beginning to herniate through the zona pellucida. Instead of removing an individual blastomere or cell, several trophectoderm cells are removed.

Day 5 Pros-

• Since the embryo is further along in development, mosacism should be lessened at this point
• Using Natera or aCGH, all chromosomes can be reviewed hopefully increasing the pregnancy rate.
• Cells are removed from what will become the placenta and not one of only 6-8 cells like on day 3 which may be easier on the embryo.
• Lower number of embryos may be transferred when all chromosomes are evaluated for health leading to fewer high-risk pregnancies

Day 5 Cons-

• An embryo must become a blastocyst and have the trophoderm layer that becomes the placenta from which the cells are taken on day 5.
• If the embryo does NOT reach blastocyst stage on day 5 and takes until day 6, the embryo must be frozen and a later Frozen Embryo Transfer(FET) must be performed.
• Because of the high rate of abnormals with IVF, a risk of a no-transfer is higher with a day 5 biopsy due to reduced numbers. Natera’s website states that a transfer is likely with minimum of 8 embryos biopsied- this does NOT take the gender selection into consideration though which means our chances at transfer are reduce beyond their quoted rates.
• Confined placental mosaicism (CPM) represents a discrepancy between the chromosomal makeup of the cells in the placenta and the cells in the baby. It is estimated to occur in 1-2% of pregnancies where the placenta contains abnormal cells but the embryo is normal.