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IVF Fertilization Process

Learn what happens in the lab during the step of IVF fertilization

As you start to explore in vitro fertilization (IVF), you’ll quickly realize that this fertility treatment involves several steps. If you’re like most patients at Texas Fertility Center, you’ll find that the step of IVF fertilization seems the most mysterious. After all, you’re an active participant in ovarian stimulation, the egg retrieval and the embryo transfer. However, with fertilization, you aren’t there when our San Antonio IVF center team combines the eggs and sperm. To demystify this process, we’ve provided an overview of what happens during fertilization in the laboratory.

An overview of IVF fertilization in the laboratory

Before we ever combine the eggs and sperm, our team first examines these important reproductive materials. When looking at the eggs, our embryologists examine them to determine their maturity and quality. As for the sperm, our andrologists look at factors like sperm count, morphology (shape) and motility (movement).

Our San Antonio IVF center team places all the mature eggs in petri dishes that contain a special culture medium. These petri dishes will eventually be placed in a climate-controlled incubator. The goal is to mimic the conditions of a woman’s reproductive system.

Within a few hours of the outpatient egg retrieval procedure, our embryologists will fertilize the eggs using one of two methods.

The conventional IVF fertilization method involves placing the sperm in the petri dish that contains the culture medium and a single egg. The goal is for the sperm to penetrate and fertilize the egg on its own.

Intracytoplasmic sperm injection (ICSI) is a more advanced option for fertilization. To achieve fertilization, one of our embryologists injects a single sperm into the egg using a needle and microscope.

Our laboratory team will check for signs of fertilization the next morning, regardless of which technique they used.

How does our team determine which fertilization method to use?

When you visit our San Antonio IVF center, your doctor will review your medical history and diagnostic test results to determine whether to use the conventional method or ICSI. If you have experienced failed IVF cycles in the past or severe male infertility is an issue, your doctor will likely suggest ICSI to provide the best chance of success.

If you have questions about the step of IVF fertilization or any other stage of in vitro fertilization, contact us. Our team is here to provide answers and support on your path to parenthood.