What is assisted embryo hatching?

Just prior to implantation, the developing embryo must "hatch" out of its outer shell (zona pellucida). Some embryos seem to have a thicker shell that may decrease their ability to implant. This may be due to the age of the woman or other unknown reasons.

With assisted embryo hatching a small opening is created in the outer shell of the embryo just prior to embryo replacement. There is an added fee for this procedure.

How and when is assisted hatching done?
Assisted hatching is done just prior to embryo transfer, usually on the morning of the third day after egg retrieval. The embryos have usually grown to six or eight cells at this stage. A fine needle is used to puncture the zona pellucida. There is little or no risk of damaging the embryo during the hatching procedure.

Who is eligible for assisted hatching?
We offer assisted hatching in situations where we expect to have a thickened zona pellucida, or have had difficulties achieving implantation, such as:

• When the woman is 38 years or older
• When we are using cryopreserved (frozen/thawed) embryos
  

How successful is assisted hatching?
In our center, the introduction of hatching in 1997-1998 produced a small improvement in pregnancy rates in women who were 38 years or older but no improvement in women less than 38 years.

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