A number of studies have suggested that assisted hatching increases the chance of achieving a successful pregnancy through IVF, especially in older mothers (usually taken as 38 years old and above).
What is assisted hatching?
Assisted hatching is a laboratory procedure carried out to increase the likelihood that an embryo will implant into the uterus. It’s normally used during IVF treatment where the first few rounds have been unsuccessful.
To implant, the embryo needs to break through the zona pullucida, its protein ‘outer shell’. In assisted hatching, a laser is used to make a small crack in the embryo’s zona pullucida, usually on the third day after fertilisation. The embryo is screened for quality before the procedure and is then transferred into a woman’s body. As failure to implant can sometimes be caused by a zona pullucida which is too thick, assisted hatching can, therefore, increase the likelihood that the embryo will successfully implant and result in pregnancy.
Who is assisted hatching suitable for?
Assisted hatching is not carried out as a routine procedure, as it carries a slight risk of complications. It’s normally used as part of the IVF cycle for women who have a low prognosis of successful implantation, which may be for a number of reasons. If embryos produced through IVF have a thick, or an irregular zona pullucida, then assisted hatching is recommended to increase the chance that the embryo can break through and implant into the uterine wall. Assisted hatching can also help when the woman has a low chance of achieving pregnancy thanks to a predetermined condition of diminished ovarian reserve, when a woman has fewer eggs than normal and thus a reduced chance of conceiving. The procedure is often used when previous rounds of IVF have failed, so that the chances of successful implantation are increased.
Success rates for assisted hatching
A number of studies have suggested that assisted hatching increases the chance of achieving a successful pregnancy through IVF, especially in older mothers (usually taken as 38 years old and above). Whilst these chances are still not certain, the difference is significant; a 2011 study reported that women over 35 undergoing IVF with assisted hatching had a rate of 30.12 per cent success for chemical pregnancies, and 27.71 per cent for clinical pregnancies, whereas women who underwent IVF without assisted hatching had a success rate of 18.96 per cent and 16.37 per cent for chemical and clinical pregnancies respectively. A number of other studies have given similar results, showing a success rate increased by 10 per cent and above.
Assisted hatching is associated with a slight increase in the likelihood of conceiving identical twins.