Through ovarian stimulation, we aim to produce many eggs, which will hopefully grow into a small group of embryos.

通過卵巢刺激，我們的目標是產生許多卵子，希望這些卵子能成長為一小批胚胎。

But when there are many embryos to choose from, how do we know which ones are the best?

但是，當有許多胚胎可供選擇時，我們如何知道哪些是最好的？

There are several ways to pick an embryo.

挑選胚胎有幾種方法。

Traditionally, the embryologist uses morphology, the size and appearance of the embryo, to determine which embryos are suitable for transfer and freezing.

傳統上，胚胎學家根據胚胎的形態、大小和外觀來確定哪些胚胎適合移植和冷凍。

Using morphology for embryo selection is not harmful to the embryo and carries no additional cost.

使用形態學方法進行胚胎選擇不會對胚胎造成傷害，也不會產生額外費用。

However, morphology is subjective.

然而，形態是主觀的。

An embryo with a lower grade may still result in pregnancy, and a high grade embryo may not.

等級較低的胚胎仍有可能懷孕，而等級較高的胚胎則可能不會懷孕。

Another way to select between embryos is through pre-implantation genetic testing.

另一種選擇胚胎的方法是植入前基因檢測。

In order to make a typical baby, an embryo must be created from an equal amount of genetic material contributed by the sperm and the egg.

為了製造一個典型的嬰兒，胚胎必須由精子和卵子提供等量的遺傳物質。

We are all made up of a unique set of DNA, which we inherit from our genetic parents.

我們每個人都由一套獨特的 DNA 組成，這套 DNA 是我們從遺傳父母那裡繼承來的。

DNA is organized into genes, and genes are packaged into larger structures called chromosomes.

DNA 被組織成基因，基因被包裝成稱為染色體的較大結構。

If you think of each person as a library, the chromosomes are the books that make up the library, genes are the sentences within the books, and DNA is the individual letters.

如果把每個人看作一個圖書館，那麼染色體就是組成圖書館的書籍，基因就是書中的句子，而 DNA 則是各個字母。

Each of us typically has 46 chromosomes arranged into 23 pairs, termed euploid.

我們每個人通常有 46 條染色體，排列成 23 對，稱為整倍體。

We all have two copies of every chromosome, one copy from the egg, and one from the sperm.

我們每個人都有兩條染色體，一條來自卵子，一條來自精子。

The first 22 pairs of chromosomes are numbered 1 through 22 based on size.

前 22 對染色體根據大小編號為 1 到 22。

The 23rd pair are sex chromosomes, XX for female or XY for male.

第 23 對是性染色體，XX 代表女性，XY 代表男性。

Genetic diseases can result from errors in part of a chromosome or the entire chromosome.

遺傳疾病可能是由部分染色體或整個染色體的錯誤造成的。

The most common cause of miscarriages and IVF failure is an embryo having too many or too few chromosomes.

流產和試管嬰兒失敗的最常見原因是胚胎染色體過多或過少。

This is called aneuploid.

這就是所謂的非整倍體。

Although this problem can arise from either the sperm or the egg, it is more common in eggs from women over 35 to 40 years old.

雖然精子或卵子都可能出現這種問題，但這種問題在 35 至 40 歲以上女性的卵子中更為常見。

IVF can help this problem by creating more eggs, increasing the pool of embryos we have to choose from.

試管嬰兒可以通過製造更多的卵子來解決這個問題，從而增加我們可以選擇的胚胎數量。

Then if we can identify the embryos that contain too many or too few chromosomes, we would avoid selecting those embryos.

那麼，如果我們能找出含有過多或過少染色體的胚胎，我們就可以避免選擇這些胚胎。

This is pre-implantation genetic testing for aneuploidy, or PGTA.

這就是非整倍體植入前基因檢測（PGT-A）。

PGTA is the modern terminology, but in the past has also been referred to as PGS or TCS.

PGT-A 是現代術語，但在過去也被稱為 PGS 或 CCS。

Here's how it works.

具體操作如下

All good quality embryos that make it to the blastocyst stage by day 5 or 6 are biopsied.

所有在第 5 或第 6 天進入囊胚期的優質胚胎都要進行切片。

A few cells are removed from the trophectoderm, or placenta, of each embryo.

從每個胚胎的滋養外胚層或胎盤中取出幾個細胞。

Embryo damage is very rare.

胚胎損傷非常罕見。

The embryo is then frozen and stored in our labs.

然後將胚胎冷凍並儲存在我們的實驗室中。

The biopsy cells are sent to a genetics facility that analyzes the DNA to determine if the embryo contains the normal 46 chromosomes.

切片細胞被送往遺傳學機構，由該機構對 DNA 進行分析，以確定胚胎是否含有正常的 46 條染色體。

This allows for the transfer of a chromosomally normal embryo, which will have a potentially higher chance of implantation than an untested embryo where we don't know the chromosomal makeup.

這樣就可以移植染色體正常的胚胎，其著床機率可能會高於未經檢測的胚胎，因為我們不知道胚胎的染色體組成。

It's important to note that PGTA increases cost by $4,000 or more, and there's a small chance that the genetic tests may return with no result.

值得注意的是，PGT-A 會使費用增加 4,000 美元或更多，而且基因檢測有可能沒有結果。

PGTA is a useful test, but even a chromosomally normal embryo does not guarantee pregnancy, nor does it completely prevent miscarriage.

PGT-A 是一種有用的檢測方法，但即使是染色體正常的胚胎也不能保證懷孕，也不能完全避免流產。

Pregnancy rates for PGTA-tested euploid embryos are upwards of 60 to 70%.

經 PGT-A 檢測的整倍體胚胎的懷孕率高達 60% 至 70%。

You will need to undergo a frozen embryo transfer cycle to transfer the normal embryo into the uterus.

您需要進行冷凍胚胎移植週期，將正常胚胎移植到子宮內。

PGTA is most beneficial for women who are over 37 to 38 years old and have multiple embryos.

PGT-A 對 37 至 38 歲以上、擁有多個胚胎的女性最有益。

Once pregnant, prenatal genetic screening is still recommended because, although it's very accurate, there is a chance that PGTA can be incorrect.

一旦懷孕，仍建議進行產前基因篩檢，因為雖然產前基因篩檢非常準確，但 PGT-A 也有可能不正確。

Even though PGTA does not create better quality embryos, it can provide valuable information and help to identify the euploid embryo sooner.

儘管 PGT-A 並不能製造出品質更好的胚胎，但它可以提供有價值的資訊，並有助於更快地識別整倍體胚胎。

At PCRM, we perform a high number of PGTA cycles, and our genetic counselors would be happy to meet with you and answer your questions.

在 PCRM，我們進行了大量的 PGT-A 循環，我們的遺傳諮詢師非常樂意與您會面並回答您的問題。