Who can benefit from IVF?
IVF (in vitro fertilization) is intended to help couples who cannot get pregnant naturally. The most common reasons for IVF include
- Reduced sperm quality and/or quantity
- Blocked fallopian tubes
- Polycystic ovary syndrome (PCOS)
- Reduced ovarian reserve
Before deciding whether IVF is the right fertility treatment for you, various examinations should be carried out. These exams include a sperm analysis (testing quantity, morphology, and mobility), hormone tests, and an ultrasound examination. If you have already had multiple miscarriages or unsuccessful IVF attempts, genetic screening is also advisable.
Fig. 1: Sperm analysis
If you decide to do IVF, you will receive training for self-administering of hormones. You need to inject hormones into the adipose tissue (abdomen, buttocks) over a period of 11-13 days. The fertility nurse assigned to you will instruct you on when and how you can do this best. The aim of the hormone injections is to make several eggs (ideally five to ten) mature to a level where they can be retrieved and fertilized.
Fig. 2: Injection of hormones into adipose tissue.
From the fifth day of your cycle, your fertility physician or nurse monitors the number and growth of follicles by ultrasound to make sure enough follicles are growing and to ensure your eggs are picked up before ovulation.
If there are too few follicles or if they are too small, the hormone dosage can be increased. Ideally, you will have enough eggs to have a good starting point for pregnancy. The hormone chorionic gonadotropin is injected to complete the maturation of the follicles.
Fig. 3: Ultrasound pictures with black bubbles representing follicles.
Follicle puncture for oocyte retrieval
Exactly 35 hours later – just before ovulation would have taken place – the so-called follicle puncture takes place. The process is often called egg collection, egg pick-up, or follicle pick-up. Most of the time (and if that is what you would like), doctors use some form of sedation during the procedure, including regional anesthesia, “conscious sedation” (in which you are awake and can respond to commands), and general anesthesia, in which you are asleep. In most clinics, propofol is used because patients can wake from the procedure with this anesthetic very quickly and don’t need intubation.
For the follicle puncture, the ovary is pierced through the vagina with a long needle connected to a suction device. The procedure is usually over after 10-15 minutes. About one hour after the procedure, you can leave the clinic, but make sure someone accompanies you because you may feel a little drowsy. There could be slight bleeding, and it would be best to spend the rest of the day in bed and relax.
The liquid sucked from the follicles ideally contains several eggs. Using a special light, embryologists in the IVF laboratory make the oocytes visible. The eggs are about 1mm in size and visible to the naked eye.
In the next step, the eggs are fertilized with the male partner’s or the donor’s sperm and put in a nutrient solution. While embryologists prefer fresh sperm obtained from masturbation (clinics have a special room for that), also frozen sperm or sperm brought from home (not older than one hour) can be used. Many IVF clinics have a large repertoire of sperm donors and frozen sperm to choose from.
In the case of ICSI (intracytoplasmic sperm injection) one individual sperm is selected and injected directly into the cytoplasm of an egg. ICSI was originally developed to treat couples with severe male-factor infertility. Nowadays, it is often used to maximize pregnancy chances even with less severe male-factor infertility, especially when a couple has multiple reasons for reduced fertility.
Fig. 3: Intracytoplasmic sperm injection (ICSI).
Development control of embryos
The fertilized eggs enter an incubator (incubator) with an ideal temperature of 27 degrees Celsius. Modern incubators are equipped with cameras that allow embryologists to monitor embryonic development without having to remove the embryos from the incubator. The eggs are left in the incubator for four to six hours after retrieval to complete the final stage of maturation. Depending on your age, up to 80 percent of the collected eggs will be mature and ready to be inseminated.
- Post-Retrieval Day 1: Visualization of two pronuclei confirms normal fertilization of the egg. One pronucleus is derived from the egg, and the other one from the sperm.
- Post-Retrieval Day 2: Embryos begin to divide.
- Post-Retrieval Day 3: Embryologists evaluate all embryos and group them based on quality. On day three, the embryos should consist of six to eight cells.
- Post-Retrieval Day 4: The embryos’ cells begin to compact on this day, preparing to form a blastocyst. The embryo is not graded by embryologists on this day because all compacting embryos look fairly similar and don’t give much indication of their quality.
- Post-Retrieval Day 5: By day five, a healthy embryo has formed a blastocyst, dividing its cells into sections that will form the fetal matter and placenta. Embryologists will re-grade the embryos, select the best one or two embryos for transfer, and place any remaining good-quality embryos either into cryo-storage or extended culture for possible freezing the following day.
The embryo transfer is ideally done five to six days after egg collection. Before transferring the embryo, your bladder should be full for ultrasound monitoring to work better. You will, therefore, be advised to drink some water before coming to the clinic.
The embryo is transferred with a catheter – a thin, flexible tube that is inserted through the vagina. Embryo transfer does not usually cause pain and takes only a few minutes. It is not necessary to lie down after the procedure. On the contrary, in order for the embryo to settle, it is better for you to move around a little.
If there are any good-quality embryos left, it is possible to freeze them in case the pregnancy test turns out negative or for a future sibling. It takes about 12 days before a pregnancy can be detected by measuring the pregnancy hormone beta-hCG in your blood or urine.
What are the chances of getting pregnant through IVF?
Pregnancy chances depend heavily on your age, the causes of infertility, the techniques used, and the experience of the team looking after you. Globally, the average probability of getting pregnant after IVF is about 25–30 percent; best-practice clinics reach 35–40 percent and up to 65 percent in couples where the woman is under 32 years of age. Pregnancy rates are lowest for women over 40.
About 15–20 percent of couples, or about half of all women over 40, suffer a miscarriage after IVF. The risk of miscarriage can be greatly reduced by a genetic examination of the embryo; however, depending on the country you’re being treated in, this exam is only permitted under certain conditions and can be very expensive.
What are the risks and side effects of IVF?
One of the main risks of IVF is overstimulation syndrome (OHSS). The ovaries overreact to the hormonal stimulation, causing many follicles to grow and estrogen levels to rise. This situation leads to fluid leaking into the abdomen, which can cause bloating, nausea, and swelling of the belly. When OHSS is severe, blood clots, shortness of breath, abdominal pain, dehydration, and vomiting are also possible. Women under 35 and women with PCOS have an increased risk of OHSS. Very rarely, women die from it.
Possible complications of IVF are injuries to your bladder, intestines, or blood vessels. In very rare cases, allergic reactions to the general anesthesia may occur. Finally, in at least two percent of IVF cycles, an ectopic pregnancy develops. Although the embryo is transferred to the uterus, the embryo travels up the fallopian tube and implants there. An ectopic pregnancy is not viable and usually results in surgery, sometimes making the removal of the affected fallopian tube necessary.