What Affects IVF Success? 7 Factors Your Doctor Considers (Beyond Age)
“I’m 38. What are my chances?”
This is the most common question fertility doctors hear. And yes, age matters—a lot.
But here’s what many people don’t realize: Age is not the only factor.
Your doctor is looking at a whole picture. Some factors you can’t change. Others you absolutely can.
Here are the 7 key factors that affect IVF success—and what you need to know about each one.
Factor 1: Ovarian Reserve (How Many Eggs You Have Left)
What it is: The number of eggs remaining in your ovaries
How it’s measured: AMH blood test + Antral Follicle Count (ultrasound)
Why it matters: More eggs = more chances. IVF success rates are higher when your ovaries produce more eggs in a single cycle.
What’s normal:
| AMH Level | What It Means for IVF |
| 1.5 – 3.0 | Good response expected |
| 0.8 – 1.5 | Moderate response |
| Below 0.8 | Low response—more cycles may be needed |
Can you change it? No. Ovarian reserve is largely determined by genetics and age. But you can preserve it by avoiding smoking and considering egg freezing earlier.
Factor 2: Egg Quality (The Hidden Factor)
What it is: How healthy your eggs are at a cellular level
Why it matters: A healthy egg is more likely to fertilize, become a good embryo, and implant. Egg quality is the #1 reason IVF fails, especially for women over 38.
What affects egg quality:
- Age (the biggest factor)
- Smoking (significantly damages eggs)
- Endometriosis (may affect quality)
- Unexplained infertility
Can you change it? Partially. You can’t reverse age, but you CAN:
- Quit smoking (improves quality within months)
- Take CoQ10 supplements (some studies show benefit)
- Maintain healthy weight
- Reduce alcohol
The hard truth: For women over 42, egg quality often makes IVF with own eggs very challenging. Donor eggs may offer much higher success rates.
Factor 3: Sperm Quality (It Takes Two)
What it is: Your partner’s sperm count, motility (movement), and morphology (shape)
Why it matters: Even perfect eggs need healthy sperm. Male factor contributes to about 40–50% of infertility cases.
What’s normal:
| Parameter | Normal Range |
| Sperm count | ≥15 million per mL |
| Motility | ≥40% moving |
| Morphology | ≥4% normal forms |
Can you change it? Yes, significantly:
- Quit smoking (huge impact)
- Reduce alcohol
- Lose weight if overweight
- Take supplements (zinc, folate, CoQ10)
- Avoid hot baths and tight underwear
For severe male factor: ICSI (injecting a single sperm directly into the egg) bypasses most sperm issues.
Factor 4: Uterine Health (Where the Embryo Lands)
What it is: The condition of your uterine lining and cavity
Why it matters: You can have the best embryo in the world—but if your uterus isn’t ready, it won’t implant.
What can go wrong:
- Fibroids (benign tumors in the uterus)
- Polyps (small growths on uterine lining)
- Adhesions (scar tissue from previous surgeries)
- Thin uterine lining
How it’s checked: Ultrasound, saline sonogram (SIS), or hysteroscopy
Can you change it? Yes, often:
- Fibroids and polyps can be surgically removed
- Thin lining can be treated with medications
- Adhesions can be cut during hysteroscopy
Factor 5: Embryo Quality (The One That Matters Most)
What it is: The health and development of your embryo after fertilization
Why it matters: The embryo is the “baby-to-be.” A genetically normal, high-grade embryo has the best chance.
What determines embryo quality:
- Egg quality (from the woman)
- Sperm quality (from the man)
- Lab conditions (where embryos grow)
Can you change it? Indirectly. You can improve egg and sperm quality before IVF. You can also use PGT (genetic testing) to identify which embryos are normal.
The role of the lab: Not all labs are equal. Ask your clinic about their embryo grading system and success rates.
Factor 6: Lifestyle Factors (What YOU Control)
What it is: Your daily habits and health
Why it matters: These are the factors YOU have the most power to change.
| Factor | How It Affects IVF | What to Do |
| Smoking | Reduces success by 50% | Quit completely |
| Weight | Low BMI or high BMI reduces success | Aim for healthy BMI (18.5–24.9) |
| Alcohol | Reduces egg quality | Avoid during IVF cycles |
| Caffeine | May reduce implantation | Limit to 1–2 cups/day |
| Stress | Can affect cycle regulation | Practice stress management |
The bottom line: Give yourself 90 days before IVF to optimize your lifestyle. Sperm and eggs both take about 90 days to regenerate.
Factor 7: Clinic and Lab Quality
What it is: The experience, technology, and protocols of your chosen fertility center
Why it matters: Two clinics can have very different success rates for the same patient.
What to look for:
- Experienced embryologists (they handle your eggs and embryos)
- Modern lab equipment (time-lapse incubators, vitrification for freezing)
- High lab standards (embryos are delicate—lab conditions matter)
- Transparent success rates (ask for age-specific data)
Can you change it? Yes—by choosing your clinic carefully.
Questions to ask:
- “How many IVF cycles do you perform per year?”
- “What is your live birth rate for someone my age?”
- “Who performs your embryo transfers? (Doctor experience matters)”
📊 Factors You Can Control vs. Factors You Cannot
| Cannot Change | Can Change (with effort) |
| Your age | Smoking (quit) |
| Your ovarian reserve | Weight (lose/gain) |
| Your genetics | Alcohol consumption |
| Past surgeries | Supplements (CoQ10, folate) |
| Sperm health (for male partner) | |
| Uterine issues (surgery) | |
| Clinic choice | |
| Stress management |
📋 IVF Success Rates by Age (For Context)
These are approximate live birth rates per embryo transfer:
| Age | Approximate Success Rate |
| Under 35 | 40–50% |
| 35–37 | 30–40% |
| 38–40 | 20–30% |
| 41–42 | 10–15% |
| Over 42 | Less than 5% (with own eggs) |
Note: These are averages. Your personal chances depend on all 7 factors above.
💬 Frequently Asked Questions
Q: Can I improve my egg quality?
A: You can protect it. Quit smoking, take CoQ10, maintain healthy weight, and reduce alcohol. But you cannot reverse the effects of age.
Q: How long before IVF should I make lifestyle changes?
A: 90 days. That’s how long it takes for eggs and sperm to regenerate.
Q: Does stress really affect IVF success?
A: Chronic stress can affect your cycle and hormone levels. Mild day-to-day stress does not significantly impact IVF. But stress management is good for YOU, regardless.
Q: Should I travel to another country for better success rates?
A: The Philippines has excellent fertility centers. Travel adds stress and cost. Choose a reputable local clinic with good success rates.
Q: What if I have all the “bad” factors?
A: Donor eggs or donor embryos offer very high success rates regardless of age or ovarian reserve. Many women choose this path.
🌸 Realistic Hope
IVF success is not a lottery. It’s a combination of factors—some you control, some you don’t.
Your job is not to control everything. Your job is to:
- Gather good information
- Work with a trusted doctor
- Optimize what you can
- Make peace with what you cannot
That’s realistic hope.
📞 Ready to Discuss Your Chances?
At Alpha Fertility Centre Philippines, we give you honest, personalized success estimates based on YOUR factors—not just averages.
Book your IVF consultation | Call: +63 999 885 4616 | Makati • Quezon City
