The combination of tiny glass tools connected to electric motor-driven robot arms, which are linked to a specialized microscope, is called a micromanipulator. The tips of these minute microtools are sometimes smaller than the head of a sperm.
Before the advent of micromanipulation, male-factor patients with poor semen analysis were often refused admission into IVF programs because it was feared that conventional IVF would fail. Today, even men whose sperm cannot leave the testicle or who do not produce mature sperm can be treated with surgery in combination with micromanipulation to achieve fertilization. Many approaches for assisting fertilization with micromanipulation have been tried, but only one method, called ICSI, has been consistently successful to date. ICSI is short for Intra-cytoplasmic sperm injection, and means that a single sperm is placed directly inside the egg using micromanipulation equipment. ICSI has revolutionized the treatment of male factor infertility in a medical as well as historical sense.
Once eggs are retrieved and sperm are collected, the embryologist uses a tiny pipette to secure the egg and injects a single sperm into the egg's cytoplasm. Remarkably, when the needle is withdrawn, the egg will reseal and assume its original shape. The resulting embryo is observed for normal cell division and, when appropriate, transferred into the woman's uterus. Several days of antibiotics and low dose steroids may be given to the woman at the time of embryo-transfer to reduce any chance of infection.
Assisted hatching was developed to improve embryo implantation. Normally, the zona pellucida, outer layer, of the embryo is shed about one week after fertilization, when the embryo emerges in order to attach to the uterus. This shedding process, known as hatching, may in some women, be inhibited by maternal age and other undetermined factors. A small opening or cut made in the outer layer of the embryos shortly before transfer helps this process, and is called assisted hatching. Great delicacy is required in making the opening of exactly the right size and type. Embryos with large gaps in their zona pellucida may unexpectedly fall out during transfer unless the utmost care is taken. Assisted hatching is now successfully applied in more than 100 IVF programs in the United States, and more than 7,000 births are estimated to have occurred after this procedure. Embryo transfer after assisted hatching is performed one or two days later than transfer after regular IVF procedures. Therefore, the highest possible standards for general laboratory conditions are required. To reduce the risk of immune reaction after transfer, low dose steriods and anti-infectives are used.
For the patient, the only way to discover the results of assisted hatching is by asking the clinic for their statistics from this procedure.