IVF Embryology Lab at Reproductive Partners

The IVF (In Vitro Fertilization) Process at Reproductive Partners

In vitro fertilization is the most advanced procedure in the repertoire of Assisted Reproductive Technologies. As a patient considering IVF, it is completely natural for you to have many questions about IVF treatment.

While it would be difficult to include all the details relevant to every unique diagnosis and corresponding IVF treatment protocol, we have assembled this guide of the most common and important aspects of IVF treatment. A consultation with one of our physicians is the most effective way to develop a customized treatment protocol designed to achieve success for your specific set of circumstances. In many cases, we are able to achieve successful pregnancies for our patients without even using IVF.


In vitro fertilization is a process where the female egg and male sperm are combined in a laboratory setting and incubated for a period of three to five days. Eggs most commonly come from the intended mother but can also come from an egg donor.

In the laboratory setting, the developing embryos can be monitored, graded, and selected for transfer back into a woman's uterus or frozen for future use. In some cases embryos are evaluated for normal chromosomes by preimplantation genetic screening (PGS) and frozen for transfer when the results are available.

In most cases the embryos are transferred back into the intended mother but in some cases a surrogate mother may be used.

The process of IVF allows us to use the embryos we believe to have the greatest likelihood of becoming a healthy baby. The entire process of IVF at Reproductive Partners is designed to increase factors that contribute to a successful pregnancy and minimize those that don't.

There are six main components of an IVF Cycle:

  1. Ovarian stimulation and monitoring
  2. Egg retrieval
  3. Egg fertilization and embryo development
  4. Embryo transfer, embryo freezing or Preimplantation Genetic Screening (PGS) and embryo freezing
  5. Luteal Phase Support for embryo transfer
  6. Cryopreservation (freezing) of extra embryos

Ovarian Stimulation and Monitoring

The IVF process starts with monitoring and optimizing the production of eggs within your ovaries.

While you are undergoing treatment, you will be monitored in our offices with ultrasound examinations and blood tests. Ultrasound is a safe procedure that is used to monitor your uterus and the ovaries. Blood tests monitor your hormonal response to medications.

Medications are used to stimulate your ovaries and increase the production of eggs. Typically a course of ovarian stimulation will include any or all of the following medications:

Oral Contraceptive Pills (OCPs)

The possible benefits include shortened use of ovarian suppressive drugs such as GnRH-agonists, decreased chance of developing ovarian cysts prior to starting gonadotropins and an improvement of your ovarian response during ovarian stimulation resulting in better egg recovery.

GnRH-Agonists (e.g.: Lupron™ [leuprolide acetate])

These medications may be prescribed to prevent premature release/ovulation of the ripening eggs or may be used as a trigger to start the process of egg release prior to egg retrieval. Possible side effects of short-term use of GnRH-agonists include irregular vaginal bleeding and symptoms similar to menopause. The effects of GnRH-agonists are very short-lived and symptoms will cease after stopping the medication or after starting on gonadotropins.

GnRH Antagonists (e.g.: Ganirelix™ [ganirelix acetate], Cetrotide™ [cetrorelix acetate])

These medications may also be prescribed to prevent premature release/ovulation of the ripening eggs. Possible side effects of short-term use of GnRH-antagonists include headache, nausea, pain at the injection site and an allergic reaction

Gonadotropins (e.g.: Follistim™, Gonal-F™, Menopur™, Repronex™, Bravelle™)

Gonadotropins are prescribed to increase the number of eggs that mature resulting in better egg recovery. Possible side effects include ovarian cysts, ovarian enlargement, ovarian hyperstimulation syndrome, and pulmonary and vascular complications. Ovarian enlargement, which may be accompanied by abdominal distention, occurs in approximately 20% of those treated with gonadotropins. This usually goes away on its own . A possible major side effect of gonadotropin stimulation is severe ovarian hyperstimulation syndrome (OHSS). This occurs in less than 1% of patients receiving these drugs. The long-term risk of ovarian stimulation is unknown. A possible association between ovarian cancer and ovulation inducing drugs in infertile patients had been suggested in a few studies, but most do not show an association. Gonadotropins are administered by means of a subcutaneous injection.

Triggers (Human Gondotropic Hormone-hCG, Lupron™ [leuprolide acetate])

Since the early days of IVF, pregnancy hormone (hCG) was used as the predominant method of triggering, maturing and starting the release process of the eggs, simulating the LH surge in nature. Typically it is administered 35 hours before the scheduled retrieval. With the production of many eggs the problem of ovarian hyperstimulation syndrome (OHHS) would occasionally develop. In order to prevent this potentially serious condition, the protocol of suppressing the LH surge with an antagonist and triggering with Lupron was developed and is now used instead of hCG in selected cases.

Egg Retrieval

Once the eggs have matured they are removed from your ovaries using ultrasound-guided follicle aspiration. A needle is placed through the vaginal wall into each follicle in the ovaries. This is performed under deep sedation, general or regional anesthesia. Complications are rare but may include bleeding, infection or injury to an adjacent organ such as bowel or bladder.

Egg Fertilization And Embryo Development

After your eggs have been retrieved, they are ready to be fertilized and become embryos. On average, about 75% of mature eggs which are retrieved will be fertilized by placing sperm and eggs together in a culture dish.

In other cases, a process called Intracytoplasmic Sperm Injection (ICSI) can be used to inject a single sperm directly into the egg. You can read more about ICSI here.

Once the eggs have been fertilized with sperm, they begin to rapidly develop into embryos. Our embryology staff carefully monitors your embryos during development and assigns a grade to each based on visual appearance as they develop. Top graded embryos are selected for transfer back into the uterus to maximize the chances of a successful outcome.

In some cases, Preimplantation Genetic Diagnosis and Screening may be performed on the developing embryos. You can read more about PGD/PGS here.

Assisted hatching (AH) may be performed on embryos just prior to day 3 transfers and in some anticipated blastocyst transfers. Assisted hatching is thought to improve implantation and pregnancy rates in some cases. You can learn more about Assisted Hatching here.

Embryo Transfer, Freezing or Preimplantation Genetic Screening (PGS) and Freezing

Transfer of your embryos back into the uterus typically happens 2, 3 or 5 days after retrieval. The day on which the transfer takes place is based on quality and quantity of your embryos. In rare cases no viable embryos are developed so an embryo transfer is not possible.

Possible side effects of embryo transfer include uterine/tubal infection, cervical bleeding, cramps, backache, miscarriage and tubal pregnancy. The incidence of tubal pregnancy in women without infertility is approximately 1%. The incidence of tubal pregnancies in IVF is very similar. A tubal pregnancy will result in the loss of the pregnancy and the possible loss of the fallopian tube.

The number of embryos which are transferred depends your age, the quality and stage of embryo development and your past treatment history. Our goal is for you to deliver a single healthy baby. Multiple pregnancies, e.g., twins, triplets or more are associated with an increased risk of prematurity when compared to singleton pregnancies.

In some cases, we can reduce the total number of embryos we transfer by allowing the embryos to develop longer in the lab prior to transfer. Embryos that have successfully continued development 5 or 6 days after retrieval are called blastocysts. Blastocysts have an increased implantation rate per embryo so fewer embryos need to be transferred. You can read more about blastocyst transfer here.

Blastocyst transfer also allows the option of Elective Single Embryo Transfer. This is particularly helpful to reduce the chance of twins when twins would be more risky than usual. You can learn more about Elective Single Embryo Transfer here.

It is common today for your doctor to recommend freezing all the embryos and delaying transfer for at least one cycle. Because of some negative effects of the ovarian stimulation on the uterine lining we have seen an increase in implantation rates with delayed transfer in some patients.

Many couples are using Preimplantation Genetic Screening (PGS) for chromosomes to insure that the embryos being transferred are chromosomally normal. This can result in higher pregnancy rates, lower miscarriage rates and a higher live birth rate with less chance of discovering a fetus with a chromosomal abnormality during the pregnancy despite the woman’s age. When PGS is performed all the embryos must be frozen to await the results before transfer. You can read more about PGS here.

Luteal Support

After ovulation, your ovaries naturally make progesterone and estradiol to both prepare the uterus for embryo implantation and then to allow the embryos the ability to continue to grow. The placenta of the growing embryo continues to make both of these hormones. Egg retrieval may decrease both progesterone and estradiol production by the ovaries so when a fresh embryo transfer is planned these hormones are administered after the egg retrieval to make sure that sufficient amounts are present to allow for the embryo(s) to implant.

In a frozen embryo transfer cycle, estrogen (Estrace™ or Minvelle™) is used to grow the endometrium and prevent premature ovulation. Progesterone is administered, usually as a vaginal insert (Endometrin™, Cinone) or intramuscular injection (progesterone in oil) to prepare the lining for implantation and then support the developing pregnancy until the placenta takes over hormone production.

Cryopreservation (Freezing) Of Extra Embryos

Many women will have more embryos than we recommend to be transferred in a single IVF cycle. These extra embryos can be stored in a frozen state so that they can be thawed for later use. On average about 90% of embryos will survive the freeze/thaw process, though there is no guarantee that a pregnancy will occur after their thaw. At this time, there is no data that indicates that the risk of birth defects from frozen embryos is any greater than fresh embryos.


In Vitro Fertilization is a process that must be tailored to each individual patient based on their specific diagnosis and fertility history. We encourage you to schedule a consultation with one of our IVF specialists who can better answer all of your questions about IVF and how it relates to your unique case.