In Vitro Fertilization

In order for pregnancy to occur, sperm must travel through the uterus to the fallopian tube, where it fertilizes an egg. While the process sounds simple, there are many factors that can stop it from happening, from low sperm count to age-related infertility. When sperm and egg are unable to meet on their own, in vitro fertilization (IVF) at NYU Langone’s Fertility Center may be an option.

During IVF, eggs are retrieved from your ovaries and fertilized with sperm from your partner or a donor. The resulting embryo is inserted back into your uterus where it ideally implants and creates a pregnancy. 

Any woman undergoing an IVF cycle must attend an onsite orientation session conducted by our nursing staff before beginning treatment. Partners are encouraged to attend this session as well. In addition to attending an in-person session, you can also view our orientation program

While every woman’s cycle is unique, here is a general overview of the IVF process.

Step One: Ovulation Induction

During a typical menstrual cycle, the ovaries release one egg each month. In preparation for IVF, fertility drugs, called gonadotropins, are injected daily to stimulate the ovaries to produce numerous eggs each month—the more eggs that are produced, the more that can be harvested, and that improves the chances of fertilization and ultimately pregnancy. 

Step Two: Egg (Oocyte) Retrieval 

When the eggs are ready to be retrieved, the procedure is performed at the Fertility Center. You are first given a moderate anesthesia, and your doctor—with the help of ultrasound—guides a needle through the vaginal opening and up to the ovaries. 

When the eggs are retrieved, they are handed to our embryologist and later fertilized with sperm from your partner or a donor. Success rates vary depending on a woman's age, her response to the medication, and the quality of her eggs and embryos. 

As with all surgical procedures, there are risks associated with egg retrieval that should be discussed with your doctor. 

Step Three: Fertilization in the Lab

When the eggs arrive in our embryology lab, our skilled staff analyzes them for maturity and then places them into an incubator to maintain proper temperature and environment. After your partner supplies a fresh sperm sample, it is mixed with the eggs or injected directly into the eggs in a process called intracytoplasmic sperm injection (ICSI). 

ICSI involves injecting a single sperm into the center of an egg. This method of fertilization can be particularly effective when male infertility results from low sperm counts or low motility.

When the egg and sperm are combined, it takes approximately 18 hours to determine if fertilization has occurred, and 24 to 72 hours to establish if the embryo is growing. The embryos stay in the laboratory for approximately five days before an embryo transfer. 

Preimplantation genetic screening and diagnosis is now performed on day 5 to 6 of embryo development at the blastocyst stage, if the patient chooses that option.

Step Four: Embryo Transfer

When you arrive for your embryo transfer, our doctor discusses the number of embryos you have, the grade of each, and makes a recommendation, based on input from our embryologists, as to which embryos should be transferred and how many. We try to adhere strictly to the American Society of Reproductive Medicine's guidelines regarding the number of embryos transferred. 

Embryo transfer is a simple technique and anesthesia is not required. A long, thin catheter containing the embryos and a small amount of fluid is passed through your cervix into your uterus, where the embryos are placed. Abdominal ultrasound with a full bladder is done simultaneously to insure optimal placement of embryos into the uterus.

Conventional embryo transfer is performed five days after the egg retrieval when healthy embryos reach the six- to eight-cell stage. Following the embryo transfer, you must limit yourself to light activities for several days and continue required medications. 

After an Embryo Transfer

When an embryo transfer is completed, it takes nine days before a pregnancy can be detected. During the days after a transfer, the following happens to the embryo:

  • Day one: The blastocyst begins to hatch out of its shell.
  • Day two: The blastocyst continues to hatch out of its shell and begins to attach itself to the uterus.
  • Day three: The blastocyst attaches deeper into the uterine lining, beginning implantation.
  • Day four: Implantation continues.
  • Day five: Implantation is complete. Cells that eventually become the placenta and fetus have begun to develop.
  • Day six: Human chorionic gonadotropin (hCG), the hormone that signals a developing pregnancy, starts to enter the blood stream.
  • Day seven: Fetal development continues and hCG continues to be secreted.
  • Day eight: Fetal development continues and hCG continues to be secreted. 
  • Day nine: Levels of hCG are now high enough in maternal blood to detect a pregnancy by a blood test.

Embryo Cryopreservation

Sometimes the IVF process produces more embryos than can be transferred in one cycle. If the embryos are of acceptable quality, they can be frozen and stored for future transfer. Because the IVF process can be difficult both physically and financially, cryopreservation gives you the option of trying IVF again later without having to again pay the cost of retrieval and fertilization. Keep in mind that there is a fee for frozen embryo storage and transfer.

Complex Types of IVF

At the Fertility Center, we consider IVF to be complicated if prior attempts of IVF have been unsuccessful or if the quality of the resulting embryos has been poor. The latter may result from many factors, including polycystic ovary syndrome or advanced maternal age.

We also specialize in treating women who have high levels of follicle stimulating hormone (FSH) who have been turned away by other fertility clinics. Generally, an FSH level of 12 or higher is seen as a sign that many of the eggs within the ovaries may be of less-than-optimal quality. Some women with high FSH have experienced unsuccessful IVF cycles elsewhere or were told that they were not candidates for IVF. 

Please contact us to schedule a consultation if you have experienced difficulties with IVF in the past. We can review your records and the results of any prior testing to help determine the best treatment plan.