The World Health Organization report estimates that an increasing number of women require assisted conception such as embryo hatching, with one in six couples experiencing a delay in conception.

The embryo’s ability to develop and implant in the uterus depends on the following:

  • the intrinsic characteristics of the embryo
  • the quality of the originating gametes
  • the quality of the embryo’s cytoplasm

Although the fertilized embryo naturally attaches to the womb after insertion by the doctor, this does not always happen. Sometimes, you might require assisted embryo hatching for better chances of success.

What Is Assisted Embryo Hatching?

Assisted embryo hatching was first reported in 1988 by Cohen, who noted these results and observations in his publications:

Assisted hatching caused a significant increase in the pregnancy success rate for patients.

There was an improvement in pregnancy rates in patients with a poor prognosis (patients over 38 years, those with repeated implantation failures, and those with thick Zona Pellucida).

Embryo Hatching

After fertilization during an in-vitro fertilization cycle, the resulting embryo is surrounded by a shell of protective cells collectively called the Zona Pellucida (ZP). And as the embryo grows, it naturally breaks out of the shell and attaches to the uterus.

Sometimes, the embryo takes longer than usual to break out of its shell. In this case, your fertility doctor makes a small “crack” in the outer shell to assist the embryo in attaching more easily to the womb (assisted embryo hatching). The process presumes that the embryo will expand, attaching to the uterine wall and leading to a successful pregnancy.

Who Is the Ideal Candidate for Assisted Embryo Hatching?

You can be a good candidate for assisted hatching if:

  • You are 38 years and older
  • You have undergone several failed IVF attempts
  • You have a frozen embryo
  • Failed pregnancies after fertilization are mainly due to the failure of the embryo to implant on the uterine wall. Assisted embryo hatching gives hope to couples who want to raise more children.

The Implantation Process

The embryo implantation happens in three phases.

  1. Apposition: This is the unstable adhesion of the embryo’s blastocysts to the uterine wall.
  2. Attachment (Adhesion): In this stage, the embryo blastocysts and the uterine wall form a more stable adhesion, believed to involve “signaling” between the two.
  3. Penetration (Invasion): The uterine wall “allows” the embryo’s trophectoderm cells to invade deep into the stroma, forming a vascular connection to the mother.

The Benefits of Assisted Embryo Hatching

Assisted embryo hatching has several benefits, including a high success rate and faster attachment to the womb. Additionally, assisted hatching helps to solve complications caused by a thick zona pellucida.

A thick ZP is associated with low rates of embryo implantations and delays. But with assisted hatching, the embryo breaks the shell and attaches easily to the embryo.

Lastly, assisted hatching yields better outcomes for embryos with a poor prognosis (excessive fragmentation, low development rate, or a thick pellucida).

Potential Risks of Assisted Hatching

While Assisted Hatching (AH) has numerous benefits, it’s also associated with some complications that include:

  • Lethal damage to the embryo
  • Reduction of embryo viability.
  • Possibility of monozygotic twinning; this is where the embryo divides into two, forming identical twins.
  • Puncturing the zona pellucida deprives the embryo of its protective shell, exposing it to toxins, immune cells, or microorganisms.


Q: What does embryo implantation involve?

A: Successful implantation requires the embryo to interact with the uterine lining.

Q: How long will an embryo implant in the uterus after assisted hatching?

A: Human blastocysts start to hatch and implant 1-2 days after embryo transfer.

Q: Which are the reasons couples opt for assisted hatching?

A: A couple may have previous failed IVF attempts and want more reassurance of having a baby.

Q: What is the main goal of performing assisted hatching?

A: Assisted embryo hatching helps to facilitate embryo hatching and implantation onto the uterine wall.

Q: Which day does the doctor perform assisted hatching?

A: Your fertility doctor will perform assisted hatching on the third day of embryo development.

Q: What causes late implantation in humans?

A: The embryo may take longer than usual due to slow embryo growth and the late development of the uterine receptivity, sometimes both.

Q: Do hatched embryos attach more easily?

A: Hatched blastocysts have a higher chance of implanting and developing into a pregnancy.

Q: What is the best diet when under assisted embryo hatching?

A: You need to feed on nutrient-dense foods for healthy and early embryo development. These foods include quality proteins, fresh fruits and vegetables, healthy fats, whole grains, nuts, and seeds.

Q: Does my sleeping position affect implantation?

A: Your sleeping position during early pregnancy influences the placental implantation position.

Q: What should I avoid during assisted hatching?

A: You should avoid strenuous physical activities such as high-impact cardio and heavy weight-lifting and take a two-week break instead.