Can An Embryo Stop Growing After Implantation?

When an embryo doesn’t implant or begins implantation but stops developing soon after (biochemical pregnancy), the most common cause is a chromosomal abnormality in the embryo itself (meaning it has too much or too little genetic material). Advancing age of the female partner increases the chance that the embryo will be abnormal.

Causes Of Embryo Arrest

There are many reasons why an embryo might stop developing. The embryo could have reduced metabolic activity or slow development and as a result, degenerate. In addition, embryos can stop growing during different stages of development. They may fail to reach the blastocyst stage for several reasons discussed below.

Chromosomal errors

Around 70% of arrested embryos display chromosomal errors.1 Chromosomes are rope-like structures inside your cells that contain DNA – i.e. the instruction manual that makes you unique. When sperm and egg come together, the mother and father pass on 23 chromosomes each, so that the resulting embryo has a total of 46 chromosomes. Sometimes, chromosomes can fail to combine correctly leading to chromosomal errors. This may include having:

. an abnormal number of chromosomes (called aneuploidy)

. more than one full set of chromosomes (called polyploidy)

. a combination of both normal and abnormal numbers of chromosomes (called mosaicism).

In addition, chromosomal errors can develop during the replication and division of the cells in the embryo. If an embryo divides abnormally during the early stages of its development (also known as the cleavage stage), this can lead to an abnormal distribution of chromosomes between cells and result in embryo arrest. Cells within the embryo can also have abnormal DNA replication and/or damaged DNA leading to embryo arrest.

Some chromosomal errors do not stop the embryo from growing, which is why preimplantation genetic screening (PGT) may be recommended.

Cell division errors

Usually, a cell within an embryo divides from one cell into two and distributes its chromosomes evenly. However, in some instances, a cell within an embryo divides from one cell to three. This is called Direct Uneven Cleavage (DUC). When DUC occurs in the first cell division, there is a higher chance of embryo arrest occurring.

The chances of embryo arrest occurring also depend on how much the cells are affected. Sometimes, an embryo may divide very quickly from one cell to two and three cells, and this rapid division can be difficult to differentiate from DUC. Under these circumstances, the rapidly dividing embryo has a greater chance of becoming a blastocyst.

Another cell division error can occur if the cell fails to divide but the nucleus (the information center of all cells which contains your chromosomes and DNA) continues to replicate. This can lead to there being more than one complete set of chromosomes inside a single cell. If this occurs in several cells, the embryo will arrest; however, if this phenomenon is present only in a few cells, the embryo still has the potential to reach the blastocyst stage.

Poor embryo development

Early cleavage within the embryo relies on special products inside the egg to drive development. Sometimes, defects in the development of an embryo reflect the quality of the egg and can cause the embryo to stop dividing.

Embryos can also undergo instructed cell death (known as apoptosis). Apoptosis is a biological mechanism that aims to remove any unwanted or damaged cells from the embryo in its early stages of development. If enough apoptosis occurs, the embryo can fail to develop further.

About Iranian Surgery

Iranian surgery is an online medical tourism platform where you can find the best doctors and fertility specialists in Iran. The price of IVF in Iran can vary according to each individual’s case and will be determined by an in-person assessment with the doctor.

For more information about the cost of IVF in Iran and to schedule an appointment in advance, you can contact Iranian Surgery consultants via WhatsApp number 0098 901 929 0946. This service is completely free.

Source:

Why didn’t my embryos grow?

https://uscfertility.org/usc-center-pregnancy-loss/early-pregnancy-loss-2/

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