To help patients trying to conceive, our new occasional blog series explains the basics of infertility and whether to seek infertility treatment, such as IVF. We hope this series is informative for you as you navigate your personal fertility journey.
When we think of hatching, we usually think of baby birds hatching from eggs. Would you be surprised to learn that human embryos also “hatch” from a kind of shell? In this blog, we will explain assisted hatching with IVF treatment and whether you might need it.
But first, a little background on hatching in human eggs: In the beginning, immature eggs lie within small, fluid-filled follicles within our ovaries. With every menstrual cycle, some eggs grow inside the follicles, becoming much bigger, so they can be fertilized.
As an egg matures, multiple layers of proteins form a protective soft shell around it. When the egg is fertilized, this shell (called the zona pellucida) hardens and prevents other sperm from entering. Then, the fertilized egg begins to divide and form multiple cells as it develops into an early embryo.
By Day 5 or Day 7 after fertilization, the embryo gets so big that it rips open the shell allowing the embryo to connect with the cells lining the uterus. It then implants in the uterus to start your pregnancy.
So what’s assisted hatching? Assisted hatching is a procedure to open the protective shell around the egg to allow the embryo to implant. In the early days of IVF, the shell around the embryo tended to harden in the lab, making implantation more difficult. Scientists came up with assisted hatching to address the problem.
Today, IVF has improved and this is not as big a concern. So, the American Society of Reproductive Medicine (ASRM) suggests that only patients with low chances of pregnancy with IVF may benefit from assisted hatching. These could include patients with two or more failed IVF cycles, poor quality embryos, and women age 38 or older.
If you opt for assisted hatching, your fertility clinic will likely perform the procedure on Day 3 of embryo culture when the embryo has typically reached the 8-cell stage of development in preparation for transfer to the uterus on either Day 3 or Day 5.
There are some risks to assisted hatching, including damage to the embryo. Some studies have also found a greater chance of identical or conjoined (Siamese) twins with the use of assisted hatching.
As always, it’s best to discuss with your doctor whether you might need this procedure and to weigh the pros and cons.