In vitro fertilization (IVF) failure is a frustrating experience for individuals and couples, and it is often caused by an embryo's failure to implant in the uterus.

For women who have failed IVF or have a poor prognosis for IVF, the fertility doctor may recommend a technique known as assisted hatching.

What Is Assisted Hatching?

After an egg is fertilized in the laboratory, the cells begin to divide. During these initial stages of development, the embryo is contained in a layer of proteins known as the zona pellicuda. In order to successfully implant into the uterine lining, an embryo has to hatch out of the zona pellucida and attach to the walls of the uterus.

Assisted hatching is a newer lab technique that was developed when fertility experts observed that embryos with a thin zona pellucida had a higher rate of implantation during IVF. With assisted hatching, an embryologist uses micromanipulation under a microscope to create a small hole in the zona pellucida. This happens on the fourth day of embryo development when the embryos contain an average of six to eight cells.

The embryos are stabilized by a holding pipette, and on the opposite side a small pipette containing an acidified solution creates a small defect in the zona pellucida. The embryos are then rinsed to remove any excess acid solution and returned to the incubator for a few hours before transfer into the uterus.

Who Should Use Assisted Hatching with IVF?

Assisted hatching is thought to be helpful for couples with a poor prognosis whose embryos are thought to lack sufficient energy to complete the hatching process.

According to the American Society for Reproductive Medicine, assisted hatching may be indicated for women with:

• advanced maternal age (older than 38)
• two or more failed IVF cycles
• poor embryo quality

Will Assisted Hatching Increase the Chances of IVF Success?

Assisted hatching has been found to help with IVF success in poor prognosis patients.

Researchers at New York-Cornell Medical College found that with assisted hatching, there was an increase in implantation in all women studied, particularly in those over age 38 or those who had an elevated FSH level on Day 3 of the menstrual cycle. Couples with multiple failed IVF cycles also benefited from assisted hatching.

Because assisted hatching is a difficult technique, the success is dependent on the embryologist's experience and technique, it is important to talk with your fertility clinic about how successful they are with the procedure.

Is Assisted Hatching with IVF Safe?

There can be complications from assisted hatching. It may be associated with damage to the embryo and damage to individual blastomeres with a reduction in the viability of the embryo. In addition, assisted hatching has been associated with an increased risk of monozygotic (identical) twins.

Talk to your fertility doctor about the risks and benefits of assistant hatching.