In Vitro Fertilization (IVF)

The IVF Process Explained, Step by Step

A typical IVF cycle at Houston Fertility Institute involves four main stages, which a physician will explain in detail to you. In general, the IVF process involves ovarian stimulation, egg retrieval, fertilization and cell division, and embryo transfer. Learn more about each step below:

Stage One: Ovarian Stimulation

Ovarian stimulation for IVF, also referred to as controlled ovarian hyperstimulation, is designed to stimulate the maturation of ovarian follicles, which contain an egg that they release during ovulation. Ovarian stimulation involves the use of fertility medications that promote the simultaneous maturation of multiple follicles and provide support for embryo transfer and pregnancy. These medications include:

IVF cycles typically include several medications, such as:

• Gonadotropins (e.g., FSH, LH) to stimulate egg development

• hCG (human chorionic gonadotropin) to trigger ovulation

• GnRH agonists or antagonists to prevent premature ovulation

• Progesterone to support the uterine lining before and after embryo transfer

During the ovarian stimulation stage, your response to medications is closely monitored with frequent ultrasounds and blood tests to measure hormone levels. This helps your physician adjust your treatment plan in real time and reduce the risk of complications, such as ovarian hyperstimulation syndrome (OHSS).

Like any medical treatment, IVF may involve side effects. Some patients experience bloating, breast tenderness, mood swings, or mild cramping. Additionally, IVF increases the chance of multiple pregnancies, especially when multiple embryos are transferred. Our team takes careful steps to reduce these risks and keep you comfortable throughout your cycle.

Stage Two: Egg Retrieval

Before the eggs can be retrieved from their follicles, human chorionic gonadotropin (hCG), a fertility medication that acts to stimulate ovulation, must be administered. This is also referred to as a “trigger shot.” Approximately 36 hours after the “trigger shot,” the eggs can be harvested using an ultrasound-guided aspiration technique. The procedure is performed under anesthesia, so there is no discomfort. You may experience mild cramping afterward, so a prescription for pain medication can be provided.

Stage Three: Fertilization and Cell Division

The eggs are then fertilized by sperm, taken from either the male partner or a donor, that have been analyzed and specially prepared. With patients who are undergoing IVF at least partly because of male factor infertility, the chances of fertilization may be increased by using intracytoplasmic sperm injection (ICSI), during which an individual sperm is injected into each individual egg.

The fertilized eggs are called embryos. Starting as a single cell, the embryo undergoes rapid cell division. By the fifth day, the embryo has approximately 100 cells. Fifth-day embryos are known as blastocysts. Preimplantation genetic testing (PGT) may be performed on one or two cells taken from the embryos for those who carry a genetic disorder or to test for chromosomal abnormalities. This test allows for the transfer of only the healthiest embryos.

Stage Four: Embryo Transfer

You and your physician will decide which transfer option will yield the best success rate according to your personalized plan. Typically, we do either a fresh blastocyst transfer (about 5 to 6 days after fertilization) or a frozen embryo transfer a few weeks later. Whether undergoing fresh or frozen embryo transfer, the procedure is very similar. During transfer, the embryos are passed through a slim catheter into the uterus.

Lifestyle and IVF Outcomes

Your lifestyle can play a meaningful role in IVF success. A balanced diet, regular exercise, and stress management techniques like yoga or counseling may help support your body through treatment. Smoking, excessive alcohol, and poor sleep can negatively impact outcomes. Our team is here to help you make healthy choices as you prepare for pregnancy.