Most of us have heard about IVF but not many of us know exactly how the process works.
Over the past 35 years, In Vitro Fertilization (IVF) has helped thousands of couples, overcome a wide variety of infertility problems enabling them to realize their dream of having children.
IVF helps infertile couples become pregnant by joining the egg and sperm outside the body of the female in a laboratory where embryos are created and later transferred back into the woman’s uterus.
The process can be broken down into parts from pre-IVF appointments and preparations through the pregnancy test making understanding the process just a bit easier.
So if you are a couple planning to undergo IVF or are just starting your infertility treatment, knowing more about the treatment can reduce your anxiety and make your journey through out the treatment more comfortable.
Initial IVF Consultation & Preparing the Ovaries for Stimulation
- Pre-IVF testing (usually blood tests)
- Consultation with doctor to review the results and plan protocol for treatment.
- The plan provides tentative dates for follow up which may change as the cycle proceeds based on how you respond to medication. The stimulation usually starts from the second or third day of bleeding in the next cycle.
- Mock Embryo Transfer (ET) is done in the previous cycle. It is a practice of how the embryos will be placed in the uterus on the day of embryo transfer with regards to the anatomy of your uterus and cervical canal. During the procedure, a thin catheter is inserted into the uterus while an abdominal ultrasound guides the process. It is a relatively painless procedure and takes only a few minutes. It is usually done with a semi full urinary bladder.
Many patients are started on the birth control pills for a particular number of days, to help:
- To decrease the chance of creating ovarian cysts that could interfere with the start of the stimulation.
- Synchronize the cohort of the follicles so they all start at the same stage, on the date collectively chosen by the doctor and patient.
- Allow the control of the timing of the cycle as per the doctor and patient.
Ovarian Stimulation and Monitoring
In a normal ovulation cycle, one egg usually matures per month.
In an IVF cycle, the goal is to have as many mature eggs as possible, as this will increase your odds of success with treatment.
In the stimulation phase of the IVF cycle, ineluctable medications are used for approximately 8-14 days to stimulate the ovaries and produce eggs.
Medications for stimulation are derivatives from the hormones FSH and LH, which are the natural hormones involved in the natural ovulation process. Some protocols use one or the other of these hormones exclusively and many use a combination.
Monitoring appointments consists of:
Trans vaginal Ultrasound – Measures the growth of the follicles and the thickness of the uterine lining, both of which should be increasing as you take the ineluctable.
Blood tests – Measures the estrogen level. The levels of estrogen in the blood are another indicator of the growth and maturation of the eggs – rising as the follicles grow.
Interaction with your doctor regarding your progress and further treatment
The Trigger Shot and Egg Retrieval
The stimulation phase ends with a trigger shot. The trigger shot provides final maturation to the developing follicles and sets ovulation in motion.
Timing is crucial in this phase because the egg retrieval must be performed prior to the expected time of ovulation.
The doctor decides when you are ready to trigger based on the two key factors that have been monitored during the stimulation phase:
- Size of the Follicles – The goal is to have as many follicles as possible be 18mm or larger since these are the most likely to contain mature eggs.
- Level of Estrogen (blood test)
Approximately 36 hours after the trigger shot the egg retrieval occurs.
Your partner’s sperm is either collected the day of the retrieval or if he is unavailable, occasionally the case for outstation or international patients, previously frozen sperms will be thawed and used.
Preanaesthetic consultation (PAC) is done with the anesthetist who assesses the patient as concerning her tests and medical history, whether she is fit to be given anesthesia or any other test is also required.
All consent forms are signed by the couple and given to the coordinator. They are given instructions for fasting and the timing of admission.
The day of egg retrieval female partner is admitted in the morning and she is instructed to remain fasting overnight, the embryologist what will happen during the fertilization phase in the embryology laboratory.
This is not general anesthesia but a quick-acting sedation that lasts as long as the procedure.
The egg retrieval itself takes only about 20-30 minutes. During the procedure, an ultrasound is used to guide a needle into each ovary and remove the follicular fluid and egg.
Inside the Lab: Embryo Development
After the eggs and sperm are collected, sorted, and prepared, the Embryology Team begins the fertilization process. There are two ways that fertilization can occur:
Conventional Fertilization: Frequently used in cases such as blocked Fallopian tubes or unexplained infertility. The embryologist isolates the healthy sperm, which are then exposed to each egg inside the embryology laboratory where fertilization occurs naturally.
Intracytoplasmic Sperm Injection (ICSI): Used in cases when the quantity or quality of sperm is poor and therefore unable to effectively penetrate the egg on its own. The embryologist selects a single healthy sperm and injects it directly into the center of each egg. Since fertilization only requires one healthy sperm, ICSI has become one of the most incredible advances in treating severe male factor infertility.
The decision about which method to use is based on the quality of the sperm.
To test sperm, an analysis is completed as part of the initial basic fertility work-up for diagnosis before treatment and then again when the semen sample is provided on the day of the egg retrieval. If the results from this analysis do not meet the parameters required for conventional fertilization, the embryologist will make the decision to switch to ICSI so that the cycle can still produce embryos and increase your chances of success.
Once fertilization occurs, the embryos begin to develop. Every morning for the next five to six days, an embryologist examines the developing embryos and adds notes in your record regarding each individual embryo.
The embryo transfer is a simple procedure that takes about five minutes to complete.
There’s no anesthesia or recovery time needed. This experience will be similar to the mock embryo transfer performed prior to starting the cycle.
The morning of the transfer, the embryologist will make a final assessment of your embryos and provide a recommendation on the number to be transferred.
These recommendations are based on overall embryo quality and the age of the embryo, which will ideally be at day 5 or 6.
The doctor will use the information provided by the embryologist and other factors related to your case, such as your age and history with previous treatments, to make their recommendation.
Often times, when patients meet a specific criteria, physicians will suggest elective Single Embryo Transfer (eSET). eSET is the transfer of a single embryo, usually a blastocyst-stage embryo, despite having many available. Transferring one high-quality embryo is found to reduce the risk of multiples while maintaining a similar chance of pregnancy. Patient criteria for eSET:
- The female partner is age 37 or younger
- It is her first cycle of IVF or she has had a previous successful cycle of IVF
- She has a good quality blastocyst
Prior to the start of the embryo transfer, the patient reviews her cycle with the physician and the final decision regarding the appropriate number of embryos to transfer is made, along with what to do with any remaining embryos.
Once the number of embryos to transfer is determined inside the laboratory, an embryologist will verify all identifiers, such as your name, identification number, and compare them to the embryo culture dish and corresponding egg datasheet. The transfer catheter is loaded with the appropriate number of embryos. Upon entering the transfer room, the embryologist will state your last name and the number of embryos in the catheter.
You will be able to watch the process on a monitor in the exam room and see the embryos as they are selected.
During the transfer, the doctor will insert the catheter and push the embryo into the uterus with a small puff of air.
The procedure is guided visually on a monitor with an abdominal sonogram. Once transferred, the doctor will slowly remove the catheter to eliminate or decrease any uterine contractions.
Since the embryo is invisible to the naked eye, the embryologist will then check the catheter under a microscope to make sure the embryo was released.
Then, you’ll be given instructions for the following two weeks until it’s time for the pregnancy test.
The Pregnancy Test
The pregnancy test occurs around 18 days after the egg retrieval.
Unlike a home pregnancy test, blood is drawn and the HCG level is measured. An HCG level of over 100 is considered to be positive although many ongoing pregnancies start out with a beta HCG level below 100.
If the cycle results in a negative pregnancy test, it’s very disappointing. It’s important to remember, you have a treatment plan with options for trying again. Your medical team will start by instructing you to stop your medications and offer you to schedule a consultation with your doctor. At that time, you’ll discuss what happened during the cycle, any changes you might make to your protocol, and ultimately how you want to proceed.