IVF or in vitro fertilization is a fertility method in which a woman’s egg is removed from an ovary to be fertilized by a man’s sperm outside a woman’s body.
IVF means in vitro fertilization (”in vitro” = in glass + “fertilization”).
This method is used in all forms of infertility: female, male and unexplained. In IVF, the woman is first stimulated with hormones to prompt more eggs to mature. Working under ultrasound guidance, the doctor inserts a thin needle into the ovary via the vagina to extract the eggs from the woman’s ovaries. The man’s sperm sample is prepared. Sperm and eggs are combined in a culture dish so that fertilization can take place. After 2-5 days, the embryo are returned to the woman’s uterus.
ICSI
Microinjection or intracytoplasmic sperm injection (ICSI) is an injection of sperm directly into the egg, used when the man’s sperm shows a low probability of penetrating the egg on its own.
The method was developed in the early 1990s and is recommended in cases of male infertility. In this procedure, the egg is injected with a single sperm instead of fertilization taking place in a test tube with the sperm advancing on its own, which is standard in IVF.
The world’s leading IVF clinics
Our clinics are among the world’s best in many areas; one of our clinics achieved the breakthrough of the first baby born with DNA from three parents.
The doctors at our IVF clinic fertilized the mother’s egg with her partner’s sperm, and then transferred the nucleus of the fertilized egg to a donor egg, from which the nucleus was removed. The child therefore has DNA from the parents and a smaller amount from the egg donor.
The method was developed to help women at risk of passing on serious genetic disorders from the genes in the mitochondria (a part of the cell outside the nucleus), known as mitochondrial disorders. However, in this case, the method was used to treat a couple who could not have children. The doctor who led the work says that they had a feeling that it could work for the couple, who had not succeeded in having a child with conventional IVF treatment.
The fertilized egg develops in the laboratory in most cases for 4-5 days – until the blastocyst stage is reached.
A description of the treatment process follows below. Don’t hesitate to get in touch if you have any questions or concerns about the process.
Hormone stimulation
In egg donation, it is the egg donor who is stimulated. If the prospective mother uses her own eggs, she is the one who undergoes hormonal stimulation. During IVF treatment, a woman is treated with hormones produced by her own body that cause her ovaries to produce more eggs than during a normal menstrual cycle.
There are two main ways of carrying out IVF treatment:
The most tried and tested method involves women using a nasal spray for three weeks before starting the injections. The FSH injections are then given for two weeks. Some women may experience problems such as sweating and mood swings.
The so-called “short treatment” involves starting FSH injections on the 2nd or 3rd day of menstruation/bleeding. After a few days, another injection of medication is added to prevent spontaneous ovulation. There are few side effects from antagonist therapy.
Ovarian reserve
Choosing the right dose of hormone for each individual woman often relies on an assessment the ovarian reserve, i.e. the ability of the ovaries to produce eggs. The doctor gets an idea of the woman’s ability to produce eggs and can then prescribe the right dose of hormones.
Stimulation for ovulation
Using an injection (trigger shot) containing a hormone similar to the one the body produces on its own during spontaneous ovulation, the doctor determines the timing of ovulation and therefore egg retrieval.
It takes about 38 hours after the trigger shot for ovulation to occur. It is critical to follow the prescribed injection time within 15 minutes. If this time is not respected, there is a risk of premature or delayed ovulation, making egg retrieval difficult or even impossible.
Egg extraction
Once the follicles have matured, usually after 10-12 days of injection treatment, they are retrieved from the ovaries. This is done via the vaginal wall under ultrasound guidance. After local anaesthesia is administered, the follicles are punctured and the fluid is aspirated with a thin needle. The embryologist takes care of each individual egg. The procedure takes about 15 minutes and is an easy procedure for most people.
After egg retrieval, the follicles fill with fluid again and the woman may feel abdominal swelling returning as abdominal tenderness for 1-2 days after egg retrieval. There may also be a small amount of bleeding from the vagina after egg retrieval, but this stops spontaneously and is not dangerous.
Egg preparation
When the follicles are emptied, the test tubes containing the fluid from the follicles are sent to the laboratory and the embryologist looks directly at the fluid under a microscope to find the eggs. The eggs are flushed clean and collected in cups containing a nutrient solution. Just like the sperm, the egg will then rest in an incubator until it is time for them to be combined.
Sperm
On the day of egg retrieval, the man provides a sperm sample. The sample is left in the men’s room in the clinic. Once the lab receives the sample, the embryologist makes an initial assessment. They look at the sample volume, the number of sperm and their motility.
The sperm sample is prepared to retrieve the best sperm for fertilization. This involves placing the sample on a gradient in a test tube. When the tube is centrifuged, immobile and lower-quality sperm become stuck in the gradient. Normal sperm with good motility are left at the bottom of the tube.
Once the sample is prepared, the embryologist makes a further assessment. Based on this, the doctor decides which method of fertilization to use. The sperm is then left to rest in a nutrient solution in an incubator until it is time to be combined with the eggs.
Fertilization methods, standard IVF or ICSI
If the sperm sample is normal, standard IVF is usually chosen. This means that the sperm are allowed to fertilize the eggs on their own. Fertilisation takes place within a few hours, but the eggs and sperm stay together in an incubator until the following morning, when the embryologist looks at them again.
A micro-injection (ICSI) is chosen if the sperm sample is of reduced quality. The man may have a low sperm count or sperm with reduced motility. Before the microinjection, the nutrient cells surrounding the egg are removed with an enzyme. This is done in order to assess the maturity of the egg. If the egg is mature, a sperm is inserted into the egg using a thin needle.
IVF is performed at leading fertility clinics in the US, Georgia and Colombia.
Embryo development
After 24 hours, two nuclei upon fertilisation
The day after egg retrieval, the embryologist can see whether or not the egg has been fertilised. If the egg is fertilised, two nuclei are visible. They look like round clear spots. One nucleus comes from the woman and the other from the man.
No nuclei are visible if the egg is not fertilised.
Sometimes 3 or more nuclei are seen in the egg. This may be because more than one sperm has made its way into the egg. These eggs are abnormal and not used.
After 48 hours, four cells
On day 2 the embryo often consists of 4 cells and on day 3 of 8-12 cells. Cell division continues and on day 4 the cells join together in what is called a morula.
After 120 hours, blastocyst
On day 5 the embryo consists of around a hundred cells and is known as a blastocyst. They look like small fluid-filled balls. The layer of cells around the blastocyst is called trophectoderm and will eventually form the placenta. Inside is an accumulation of cells that will go on to form the fetus. The blastocyst is surrounded by a shell. Once the blastocyst has developed and is ready to implant in the uterine lining, it “hatches” and leaves the shell.
Two methods of embryo freezing: slow freezing and fast freezing
It often turns out that multiple eggs of good quality are fertilized and develop. In most cases, only one embryo is transferred, so it is valuable to be able to freeze any surplus embryos. These are used if the fresh embryo does not implant or if you want to try for more children at a later date.
Slow freezing, as the name suggests, means that the embryos are frozen slowly. The embryo is rinsed in various solutions to remove water from the cells. This is done to protect the embryo from frost damage. The embryo is then aspirated into a little straw which is placed in a machine. The machine gradually lowers the temperature in the straw over the course of about one hour.
The other method, vitrification – fast freezing, means very fast freezing. Just like in slow freezing, the embryo is rinsed in various solutions. The embryo is then placed on a small spatula that is inserted in a larger straw. There is liquid nitrogen around the straw. This makes the air in the straw so cold that the embryo is immediately “vitrified”.
PGT testing on embryos
Common tests on embryos in IVF include preimplantation genetic testing (PGT, formerly PGS), which can be performed to analyse the embryos’ chromosomes or genes before they are transferred to the uterus.
There are three types of PGT:
- PGT-A to detect aneuploidy (abnormal number of chromosomes)
- PGT-M to detect individual disorders
- PGT-SR to detect chromosomal rearrangements
These tests can help increase the likelihood of uncomplicated pregnancy and reduce the risk of miscarriage or genetic diseases.
Embryo transfer
Just before the surrogate mother arrives for transfer, the embryos are assessed. The embryo judged to be of the highest quality is selected for transfer.
An ultrasound is done before the transfer. A guide catheter is then inserted into the uterus. The embryologist inserts the selected embryo into a thinner catheter and hands it to the doctor. The catheter is placed inside the guide catheter and the embryo is inserted into the uterus. This usually only takes a few minutes and most women find it painless.
The uterine cavity is comprised of two layers that lie close together without forming a cavity. These layers consist of fuzzy tissue almost resembling thick velvet and the embryo placed in the womb is the size of a grain of dust. The surrogate mother can then go about her routine business until the pregnancy is confirmed and during the pregnancy.
After embryo transfer, pregnancy test
Our clinicians perform pregnancy tests on surrogate mothers in different ways. After the embryo has been transferred back to the uterus, a period of waiting and expectations begins. Pregnancy tests are done about 15-20 days after the embryo transfer and only at this point will the couple know if a pregnancy has occurred or not.
If no pregnancy is achieved, an individual follow-up is done with the prospective parents and the surrogate mother to determine next steps.