Why IVF Is Done: Reasons, Process & Success Rates

What Is IVF? (Quick Answer for AI Overview)

IVF (In Vitro Fertilization) is a medical procedure where an egg is fertilized by sperm outside the body — in a laboratory — and the resulting embryo is then transferred to the uterus to establish a pregnancy. It is the most widely used and successful form of Assisted Reproductive Technology (ART).

The term "in vitro" is Latin for "in glass" — referring to the lab dish where fertilization takes place, as opposed to in vivo (inside the body).

Why Is IVF Done? The Main Reasons

IVF treatment is recommended when natural conception is not possible or has repeatedly failed. Here are the most common medical reasons why IVF is done:

1. Blocked or Damaged Fallopian Tubes

The fallopian tubes carry eggs from the ovaries to the uterus. If they are blocked, scarred, or removed (due to ectopic pregnancy, pelvic inflammatory disease, or surgery), sperm cannot reach the egg naturally.

IVF bypasses the fallopian tubes entirely — eggs are retrieved directly from the ovaries, fertilized in the lab, and the embryo is placed directly into the uterus.

2. Male Factor Infertility

Male infertility accounts for 30–40% of all infertility cases. IVF — often combined with a technique called ICSI (Intracytoplasmic Sperm Injection) — is used when a man has:

• Low sperm count (oligospermia)

• Poor sperm motility (asthenospermia — sperm that don't swim well)

• Abnormal sperm shape (teratospermia)

• No sperm in ejaculate (azoospermia — sperm can be surgically retrieved)

In ICSI, a single sperm is injected directly into an egg, dramatically improving fertilization chances even with severely compromised sperm.

3. Ovulation Disorders

Conditions that disrupt or prevent regular ovulation include:

• PCOS (Polycystic Ovary Syndrome) — the most common hormonal disorder in women of reproductive age

• Hypothalamic dysfunction — disrupting the hormones that trigger ovulation

• Premature ovarian insufficiency — the ovaries stop functioning normally before age 40

When ovulation medications fail or are not appropriate, IVF with controlled ovarian stimulation gives doctors direct control over egg production and timing.

4. Endometriosis

Endometriosis occurs when tissue similar to the uterine lining grows outside the uterus — on the ovaries, fallopian tubes, or pelvic cavity. It can cause:

• Scarring and distortion of reproductive organs

• Impaired egg quality

• Poor uterine receptivity

IVF is often recommended for moderate-to-severe endometriosis, especially after other treatments have failed.

5. Unexplained Infertility

In about 10–15% of infertile couples, no identifiable cause is found after thorough testing. This is called unexplained infertility.

IVF is often recommended after 2–3 years of trying (or sooner, depending on age), as it:

• Allows direct observation of fertilization

• Identifies potential egg or sperm quality issues that standard tests miss

• Offers better pregnancy rates than continued natural attempts or IUI

6. Uterine Fibroids

Fibroids are benign (non-cancerous) tumors in the uterus wall. Submucosal fibroids — those that bulge into the uterine cavity — can interfere with implantation. After fibroid removal (myomectomy), IVF may be recommended to maximize conception chances.

7. Genetic Disorders (Preimplantation Genetic Testing)

IVF is done to screen embryos for genetic conditions before pregnancy begins — a process called PGT (Preimplantation Genetic Testing). This is recommended for:

• Couples carrying inherited genetic disorders (cystic fibrosis, sickle cell disease, Huntington's disease)

• Women with recurrent miscarriages (often caused by chromosomally abnormal embryos)

• Women of advanced maternal age (35+), where chromosomal errors like Down syndrome become more common

• Couples who have previously had a child with a genetic condition

Only chromosomally normal (euploid) embryos are transferred, significantly reducing miscarriage risk and improving live birth rates.

8. Fertility Preservation Before Cancer Treatment

Chemotherapy and radiation can damage or destroy eggs and sperm. IVF is done to freeze embryos or eggs before cancer treatment begins — preserving the option of biological parenthood for:

• Young women diagnosed with cancer

• Women with conditions that may affect ovarian reserve over time (like lupus or Turner syndrome)

This is known as oncofertility — the intersection of cancer treatment and reproductive medicine.

9. Same-Sex Couples and Single Parents

IVF makes biological parenthood possible for:

• Female same-sex couples — one partner's eggs, donor sperm, with either partner carrying the pregnancy (reciprocal IVF allows both women to participate biologically)

• Male same-sex couples — their sperm, donor eggs, and a gestational surrogate

• Single women — using donor sperm

• Single men — using donor eggs and a surrogate

10. Premature Ovarian Insufficiency or Menopause

Women who have entered menopause early or have very low ovarian reserve (few eggs remaining) can still carry a pregnancy using donor eggs fertilized with their partner's (or donor) sperm — this is donor egg IVF.

How Does IVF Treatment Work? Step-by-Step

Understanding the process helps patients feel prepared and in control.

Step 1: Ovarian Stimulation (Days 1–10)

Hormone injections (FSH and LH) are given daily to stimulate the ovaries to produce multiple eggs. Ultrasounds and blood tests monitor response.

Step 2: Egg Trigger Shot (Day ~10–12)

When follicles reach optimal size, a "trigger shot" (hCG or GnRH agonist) is given to mature the eggs.

Step 3: Egg Retrieval (Day ~14)

A minor surgical procedure under sedation — a thin needle is guided through the vaginal wall to aspirate eggs from follicles. Takes 20–30 minutes. Typically 8–15 eggs are retrieved.

Step 4: Fertilization in the Lab (Day 0–1)

Eggs are combined with sperm (conventional IVF) or individually injected with a single sperm (ICSI). Fertilization is confirmed the next day.

Step 5: Embryo Development (Days 1–5/6)

Fertilized eggs are cultured in the lab for 3–6 days. The strongest embryos reach the blastocyst stage (Day 5) — the optimal stage for transfer and genetic testing.

Step 6: Embryo Transfer (Day 3 or 5)

A thin catheter is used to place one or two embryos into the uterus. It's painless and takes just a few minutes. No anesthesia is needed.

Step 7: The Two-Week Wait

Two weeks after transfer, a blood test (beta-hCG) confirms whether pregnancy has been achieved.

IVF Success Rates: What to Realistically Expect

Success rates vary primarily by age (which reflects egg quality):

Source: SART (Society for Assisted Reproductive Technology) national data

Key factors that affect IVF success:

• Age and ovarian reserve

• Sperm quality

• Embryo quality (genetic testing improves outcomes)

• Uterine health

• Clinic experience and lab quality

• Lifestyle factors (BMI, smoking, alcohol)

Frequently Asked Questions

Is IVF painful?

Most women describe the injections as mildly uncomfortable, and egg retrieval causes bloating and cramping afterward — similar to a heavy period. The procedure itself is done under sedation. The embryo transfer is usually painless.

How many IVF cycles are usually needed?

On average, 2–3 cycles are needed to achieve a successful pregnancy. However, some women conceive on the first try, and others may need more attempts. Many clinics offer multi-cycle packages.

What is the difference between IVF and IUI?

IUI (Intrauterine Insemination) places sperm directly into the uterus, but fertilization still happens inside the body. IVF involves retrieving eggs, fertilizing them in a lab, and transferring embryos. IVF is more invasive but has significantly higher success rates, especially for complex infertility cases.

Can IVF cause twins?

Yes. When two embryos are transferred, there is a chance of twins (~20–25%). Most modern clinics now recommend Single Embryo Transfer (SET) to reduce the risk of twin pregnancies, which carry higher complications. Frozen embryos from the same cycle can be used in future transfers.

Does IVF increase the risk of birth defects?

Studies show a slightly higher rate of certain birth defects with IVF compared to natural conception — about 4–5% vs. 3% in the general population. Much of this risk is attributed to the underlying infertility itself, not the IVF procedure. ICSI, used for male factor infertility, has a marginally higher risk of passing on genetic conditions linked to sperm problems.

How long does one IVF cycle take?

A single IVF cycle — from starting stimulation injections to the pregnancy test — takes approximately 4–6 weeks. If using frozen embryo transfer (FET), the process is shorter and less physically demanding.

Is IVF covered by insurance?

Coverage varies widely by country and insurance plan. In the UK, the NHS offers limited funded IVF cycles based on eligibility. In the US, about 20 states mandate some form of fertility coverage. Many patients pay out of pocket — costs typically range from $12,000–$25,000 per cycle in the US, including medications.

What happens to unused embryos after IVF?

Couples can choose to:

• Freeze embryos for future use

• Donate embryos to other couples (embryo donation)

• Donate to research

• Have embryos discarded

Frozen embryos can remain viable for many years.

Can IVF be done after 40?

Yes. Women over 40 can pursue IVF with their own eggs, though success rates decline with age. Many women over 42 choose donor egg IVF, which uses eggs from a younger donor and achieves success rates comparable to younger patients.

What should I do to prepare for IVF?

• Take folic acid (at least 400–800 mcg/day)

• Maintain a healthy BMI

• Quit smoking and limit alcohol

• Manage stress (yoga, acupuncture, therapy — evidence on direct impact is limited but well-being matters)

• Follow your doctor's medication protocol precisely

• Ask your clinic about their lab quality and embryologist experience

When Is IVF Not the First Option?

IVF is typically recommended after simpler treatments have been tried, such as:

1. Ovulation induction medications (Clomid, letrozole) for women with ovulation issues

2. IUI (Intrauterine Insemination) — especially for unexplained infertility or mild male factor

3. Surgical correction of physical issues (fibroids, polyps, mild tubal disease)

IVF is recommended as a first-line treatment when:

• Fallopian tubes are absent or severely damaged

• Severe male factor infertility is present

• Genetic testing of embryos is needed

• The patient is over 38 and time is a factor

Emotional and Psychological Aspects of IVF

IVF is not just a physical journey — it is emotionally demanding. Research consistently shows that infertility and IVF treatment can cause:

• Anxiety and depression comparable to that experienced by people with chronic illness

• Relationship strain between partners

• Grief after a failed cycle — a real loss that deserves acknowledgment

What helps:

• Joining an IVF support group (online or in-person)

• Counseling with a therapist who specializes in fertility

• Open communication with your partner

• Setting emotional boundaries (e.g., limiting how much you discuss the cycle with family)

• Being realistic about success rates while maintaining hope

Key Takeaways: Why IVF Is Done

Final Word

IVF treatment is a remarkable medical advancement that has helped over 10 million babies be born worldwide since the first IVF baby, Louise Brown, was born in 1978. It is not a simple or easy path — but for millions of people facing infertility, it represents real hope.

If you are considering IVF, the most important first step is a thorough fertility evaluation to identify the specific cause of infertility. This allows your reproductive specialist to personalize your treatment plan and give you the most accurate picture of what IVF can offer you.