IVF and IUI Treatment Processes

In Vitro Fertilization (IVF) and Intrauterine Insemination (IUI) are the most common and successful assisted reproductive technologies, offering hope to couples unable to conceive naturally. IUI involves placing specially prepared sperm directly into the uterus, whereas IVF is a more comprehensive process where eggs retrieved from the mother are fertilized with the father's sperm in a laboratory, and the resulting embryo is transferred to the uterus. The criteria for applying either method, their success rates, and the treatment processes vary depending on the patient's age and the underlying cause of infertility.

Women under the age of 35 should consult a specialist if they cannot conceive after 1 year of unprotected intercourse, while women over 35 should seek help after 6 months.
For an IUI procedure, the woman must have at least one open fallopian tube, and the man must have a sufficient number of motile sperm.
IVF success rates generally hover around 35-40%, though this highly depends on the woman's age and ovarian reserve.
A uterine X-ray (HSG) and blood tests play a critical role in determining the most suitable treatment method for the individual.
In IVF, preimplantation genetic testing (NGS) and Day 5 embryo transfers significantly increase the chances of a healthy pregnancy.

What are IVF and IUI?

For couples dreaming of having a child but unable to achieve this naturally, modern medicine offers two primary solutions. The simplest answer to what IUI is: it is the process of depositing washed sperm with enhanced motility and quality directly into the uterus using a thin catheter during the woman's ovulation period. This procedure shortens the distance the sperm must travel to reach the egg, thereby increasing the chances of fertilization.

IVF treatment, on the other hand, is a more extensive process. It begins with stimulating the woman's ovaries with medication to produce multiple eggs. These eggs are then retrieved and combined with sperm in a laboratory setting. The highest quality embryos resulting from this fertilization are selected and placed into the mother's uterus. The fundamental difference between IVF and IUI is where fertilization takes place; in IUI, fertilization occurs naturally within the woman's fallopian tubes, while in IVF, it happens in an embryology lab.

Causes of Infertility and Risk Factors

"If all our tests are normal, why aren't we getting pregnant?" is one of the most frequent questions we encounter in our clinics. Unexplained infertility affects approximately 15% of couples. Current medical tests cannot perfectly measure every single parameter required for pregnancy. For instance, while ultrasounds or blood tests can give us a clear idea about the number of eggs a woman has, it is impossible to evaluate the actual quality of an egg while it is still inside the body.

Furthermore, standard tests cannot reveal whether the fallopian tubes successfully "catch" the egg, the status of the cellular receptors in the uterine lining where the embryo implants, or the adequacy of the enzymes in the sperm's head needed to penetrate the egg shell. Age is one of the most significant risk factors; especially after age 35, both the quantity and quality of a woman's eggs decline rapidly. For men, smoking, obesity, environmental toxins, and stress are major risk factors that negatively impact sperm quality.

When Should Couples Seeking a Baby See a Doctor?

Timing is crucial when trying to conceive. As a general medical guideline, women under 35 should consult a specialist if pregnancy does not occur after 1 year of regular, unprotected intercourse. For women over 35, this waiting period is limited to 6 months due to the accelerated decline in ovarian reserve.

For couples feeling impatient during this waiting period, there are natural methods to try at home. Women can track their ovulation windows and engage in intercourse every other day during this time. However, women with irregular menstrual cycles will find it difficult to pinpoint ovulation and should see an obstetrician and gynecologist without waiting for a full year. In the early stages, the male partner can provide a simple sperm test (spermiogram), while the female partner's ovarian reserve can be assessed via an Anti-Müllerian Hormone (AMH) blood test. Conditions that can indirectly affect reproductive health, such as vaginal infections, should also be treated during this period.

Pre-Treatment Tests and the Diagnostic Process

When couples visit the clinic, a detailed evaluation is conducted to uncover the underlying cause of infertility and create the most accurate treatment plan. Certain diagnostic tests are requested for both partners during this process:

Semen Analysis (Spermiogram): Examines the sperm count, motility, and structural (morphological) features in the sample provided by the male partner.
Anti-Müllerian Hormone (AMH) Test: Checked via the woman's blood, this value indicates the ovarian reserve and the potential response to treatment.
Hysterosalpingography (HSG): A uterine X-ray that checks if the fallopian tubes are open and detects any polyps, fibroids, or congenital abnormalities in the uterine cavity that might prevent embryo implantation.
Transvaginal Ultrasonography: Performed on the 2nd or 3rd day of menstruation to evaluate the general condition of the uterine lining and ovaries.
Hormone Profile: Measures the levels of hormones that directly affect the reproductive system, such as thyroid function tests (TSH) and prolactin.

There is a widespread public anxiety that an HSG is a highly painful procedure. However, with modern technologies, this procedure is not as painful as rumored; it can even be performed under light anesthesia for patients with a low pain threshold. This test is mandatory to prevent conditions like fluid accumulation in the tubes (hydrosalpinx), which can leak toxic fluid onto the embryo and cause miscarriages.

Who Needs IVF? (Direct Candidates for IVF)

In some cases, it is a medical necessity to proceed directly to IVF rather than wasting time with simpler methods like IUI. The answer to who needs IVF depends on the patient's age and current medical profile. Couples are recommended to proceed directly to IVF in the following situations:

Couples with a history of repeated, unsuccessful IUI attempts.
Women whose HSG results show that both fallopian tubes are blocked, damaged, or have been surgically removed.
Male factor cases where the motile sperm count is below 5 million, or there are severe morphological or motility defects.
Patients with severely diminished ovarian reserve due to advanced age (especially 38-40+) or a risk of early menopause.
Couples who are carriers of genetic diseases or who experience recurrent miscarriages suspected to be of genetic origin.

The IUI and IVF Treatment Processes

In the IUI process, treatment begins on the 2nd or 3rd day of the woman's menstrual cycle with egg-stimulating pills or low-dose injections. The goal is to encourage the growth of 2 or 3 eggs, rather than the single egg that normally develops each month. After about 11-14 days of monitoring, when the eggs reach 18-20 mm in size, a trigger shot is administered. Approximately 36 hours after this injection, sperm collected from the male partner is washed and prepared in the lab, then deposited into the uterus via a painless procedure that requires no anesthesia.

In the IVF process, treatment also begins on the 2nd or 3rd day of the cycle, but with higher-dose injections compared to IUI. The eggs are grown under strict ultrasound monitoring for 11-12 days. About 36 hours after the trigger shot, the eggs are retrieved vaginally under ultrasound guidance while the patient is under light anesthesia (sedation) for 10-15 minutes (the OPU procedure). On the same day, fertilization is achieved in the lab using the partner's sperm. Embryo development is monitored day by day, and the healthiest one is selected and transferred to the mother's uterus.

Differences Between IVF and IUI, and Success Rates

The difference between IVF and IUI is evident not only in how the procedures are performed but also in the patient groups they target and their success rates. The success rate for IUI is generally around 12-18%. Therefore, wasting time with IUI is not recommended for patients with low ovarian reserve or those in an advanced age group.

IVF success rates are significantly higher. The general average is around 35-40%, but this rate varies greatly depending on the woman's age. Success rates begin to decline after age 35 due to a drop in egg quality. To maximize the chances of success, laboratory conditions must be impeccable. After fertilization, the embryo is expected to reach Day 5 (the blastocyst stage). Embryos that reach Day 5 have a much higher implantation potential. However, not every Day 5 embryo is genetically healthy. This is where Next Generation Sequencing (NGS) comes into play. A tiny cell sample taken from the embryo is screened for chromosomal abnormalities, and only a genetically normal embryo is transferred. With this method, pregnancy rates for transferred embryos can approach 80%.

Despite this, the reasons success is never 100% include defects in the implantation receptors of the uterine lining and the embryo's inability to produce the energy needed to continue dividing (due to mitochondrial dysfunction).

Frozen Embryo Transfer After Genetic Screening

When genetic screening (NGS) is performed in IVF, it takes a certain amount of time for the biopsied samples to be analyzed and for results to return. A common source of anxiety is whether the results are immediate. On the day the biopsy is sent for genetic testing, the embryo is frozen using an ultra-fast freezing method (vitrification) that does not damage its cellular structure.

Genetic results usually take a few weeks. When a normal result is confirmed, the mother's uterus is prepared for transfer using specific medications or by tracking her natural cycle. Once the uterine lining (endometrium) reaches the desired thickness, the frozen embryo is thawed and transferred. Frozen Embryo Transfer (FET) is frequently preferred in elite centers not just for patients waiting for genetic results, but for all patients. The reason is to avoid the potential negative effects of high-dose stimulation drugs on the uterine lining and to completely eliminate the risk of Ovarian Hyperstimulation Syndrome (OHSS) that can develop after retrieving a large number of eggs. Resting the uterus significantly increases the embryo's chances of implantation.

IVF Emergencies: When to Seek Medical Help?

IVF and IUI treatments are generally highly safe procedures. However, the hormone medications used and the surgical interventions (egg retrieval) can rarely lead to complications. Throughout the treatment process, patients should listen to their bodies and contact a physician without delay in case of unusual symptoms. If you experience any of the following, you should immediately go to your hospital's emergency department or call 112:

Severe, persistent abdominal or pelvic pain,
Sudden and extreme abdominal swelling or a feeling of tightness,
Shortness of breath, chest pain, or rapid breathing,
Heavy vaginal bleeding soaking more than one pad a day,
A persistent fever of 38°C or higher, accompanied by nausea and severe vomiting.

Shortness of breath and extreme abdominal swelling, in particular, can be warning signs of OHSS (Ovarian Hyperstimulation Syndrome) and require urgent medical intervention.

The IVF and IUI Process at BHT CLINIC

At the BHT CLINIC İstanbul Tema Hastanesi IVF Center, we stand by you on your journey to parenthood with the latest medical technologies and personalized treatment protocols. The most common patient group applying to our center consists of couples with diminished ovarian reserve or those marrying at an older age. Rather than rushing these patients, we aim to retrieve the highest quality egg through rigorous ultrasound monitoring. In cases of recurrent implantation failure, we successfully apply advanced methods like the ERA test, which calculates the embryo's implantation window down to the millimeter.

Furthermore, prior to treatment, we offer multidisciplinary support with all our departments, primarily our Infectious Diseases unit, for any infections or immune system issues that might affect reproductive health. We know that the stress of struggling to conceive lowers pregnancy chances and strains a couple's relationship. Therefore, we view psychological support as an integral part of the medical treatment. With our 24/7 emergency department and expert staff, you are safe at every step. To take the first step on this special journey and learn the best treatment plan for your situation, you can consult our specialists by booking an appointment.

Frequently Asked Questions

How long does IVF treatment take?

IVF treatment begins on the 2nd or 3rd day of menstruation and takes about 12-14 days up to the egg retrieval procedure. If a fresh transfer is planned, the process is completed 3-5 days later; however, if the embryos are to be frozen, the transfer is postponed to a subsequent menstrual cycle.

Is the IUI procedure painful?

No, IUI is generally a painless procedure. Similar to a routine gynecological exam, sperm is deposited into the uterus using a thin, soft catheter. No anesthesia is needed, and the patient can return to her daily life on the same day.

Who is recommended for genetic screening (NGS) in IVF?

NGS is recommended to select a healthy embryo for women of advanced maternal age (especially over 38), patients with recurrent IVF failures, those with a history of recurrent miscarriages, and couples where one partner is a known carrier of a genetic disease.

Is there an age limit for IVF treatment?

While there is no legal age limit, the woman's ovarian reserve and egg quality are the deciding factors. Generally, after the age of 45, the chance of achieving a pregnancy with a woman's own eggs is so low it relies on a miracle; therefore, early diagnosis and treatment are critical.

How safe is embryo freezing?

With modern vitrification (fast freezing) technology, the survival rate of embryos after freezing and thawing is over 95%. Pregnancy rates achieved with frozen embryos are equivalent to, and sometimes even higher than, those achieved with fresh transfers.

This article is for informational purposes only; please consult your physician for diagnosis and treatment.

IVF and IUI: Treatment Processes and Success Rates