Assisted hatching is a relatively new technique used during certain IVF procedures. It is performed in order to help an embryo hatch out of its protective layering and implant into the uterus. During the initial stages of development, embryo is contained in a layer of proteins, known as the zona pellicuda. The zona pellicuda is designed to protect the embryo until it reaches the blastocyst stage of development. In order to successfully implant into the uterine lining, the embryo needs to hatch out of this zona pellicuda and attach to the walls of the uterus.

Sometimes, embryos have difficultly in hatching out of their protective layer. This can occur if the zona pellicuda is too thick or if the embryo does not have enough pressure from the cells to break through the layer. Assisted hatching attempts to help these embryos break out away from the zona pellicuda by creating a small hole in this outer lining.

• Women over the age of 37;
• Post-thaw embryos;
• Women with poor quality embryos;
• Women who have two or more failed IVF cycles;
• Couples whose embryos have a particularly thick zona pellicuda(>17 µ );
• Women with elevated FSH on day 3 of their menstrual cycle;
• Severe endometriosis;
• Embryos with slow cleavage rate, blastomeres number;
• Unexplained infertility.

Clinical studies have been in progress for several years to look at the effects of assisted hatching on pregnancy rates following IVF. Data has also been collected on how assisted hatching affects the rate of live births, multiple births, miscarriage and still births.

• Women who had previously had at least two IVF failures were definitely helped by assisted hatching, even if fresh embryos were being implanted.
• Women thought to have a low chance of pregnancy and who were having frozen embryo transfer also had higher rates of pregnancy after assisted hatching.
• Women who had assisted hatching had a significantly higher chance of having a multiple birth.
• Miscarriage rates were similar whether assisted hatching was used or not.

Only the embryos that are to be replaced will undergo assisted hatching. There is a very small risk that one or more of the cells within the embryo may be damaged during the procedure, although this may not prevent the continued development of the embryo. There is a tiny risk that the whole embryo may be damaged by the procedure in which case another embryo maybe selected. The experience of the MFS embryologists over the years has shown that the damage rate is almost negligible.

Several follow-up studies have been carried out worldwide and show no increase in the risk of abnormalities on children born from assisted hatching embryos. Any long-term abnormalities are currently unknown.