04 Nov The Basics of Assisted Hatching from US Fertility Network
One frustrating aspects of assisted reproductive technology (ART) is failure to achieve or maintain pregnancy. This is true for couples and fertility specialist alike. Couples who have attempted various forms of ART with poor results find home with assisted hatching.
What is Assisted Hatching?
Embryos with a thin zona pellucida (shell around them) have a higher rate of implantation into the uterus during in vitro fertilization. Because of this factor, specialists postulated that creating a small defect in the shell could result in a higher chance of embryo hatching (shedding of the shell) and implantation into the endometrium (uterine lining). Assisted hatching is the name for developing the minor defect in the zona pellucida.
Assisted Hatching improves Implantation Success
Controlled trials at Cornell Medical College in New York show significant increase in implantation rates for women over the age of 35 years who use assisted hatching. In addition, rates are higher when women have an elevated FSH level on day three of the menstrual cycle. Those who benefit from assisted hatching are couples who fail IVF cycles because their embryos lack necessary energy to complete the hatching process. Experts believe many women fail using IVF because their eggs have a thick shell, which inhibits hatching of the embryo.
When assisted hatching is used, the embryos implant one day early, allowing for a greater opportunity for implantation to occur. The chance of success increases when the endometrium is prepared using ovarian stimulation. There is a slight risk of damaging the embryo when micromanipulation occurs. To protect the embryo from inflammatory cells, the client takes steroids and an antibiotic four days before the procedure.
The Assisted Hatching Procedure
The first step of any pregnancy is for the sperm to fertilize an egg. With natural conception, fertilization takes place in the woman’s fallopian tube following intercourse. The fertilized egg then is called an embryo, and it travels from the tube to the uterus for implantation. With IVF, the egg and sperm are combined in the laboratory (outside the female body), either in a petri dish, or by using intracytoplasmic insemination (technician places sperm inside egg).
The assisted hatching technique is performed three days after fertilization, when the embryo has developed. The zona pellucida can be dissolved using an acidic mixture, or the outer layer is ruptured using a fine needle or laser. The micromanipulation technique requires the use of a microscope, robotic assistance, and various tools.
Candidates for Assisted Hatching
Not every couple requires assisted hatching for IVF to be a success. According to the American Society of Reproductive Medicine, assisted hatching will benefit women who:
- Had at least two unsuccessful IVF cycles
- Are over the age of 38 years
- Have embryos with a thick outer wall
Success Rates with Assisted Hatching
According to a recent study, assisted hatching works! The results involve women who received assisted hatching with stimulated IVF using fresh embryos created with their own eggs. Percentages of cycles that achieved live births are:
- 37% for women age 34 and younger
- 26% for women age 35 to 37 years
- 21% for women age 38 to 39 years
- 14% for women age 40 to 42 years
- 6% for women age 43-44 years