Introduction
Do you ever wonder why IVF works for some couples in the very first cycle, while others take longer despite doing everything “right”? That is because the IVF success rate depends on several factors such as age, AMH levels, pre-existing conditions like PCOS or thyroid and even lifestyle choices. For instance, the IVF success rate in India currently ranges between 20% to 40% per cycle. The best part of it all, despite the above, is that you can improve your chances of conceiving. So, read on to find out what affects IVF success and the powerful changes you can bring into your routine.
What is In Vitro Fertilization (IVF)?
In Vitro Fertilization, or IVF, is a medical process performed to assist couples who are having trouble having a child of their own naturally. “In vitro” is defined as “outside the body,” referring to the lab setting where the process happens. Globally, over 2.5 million IVF cycles are performed each year, with around 500,000 babies born annually through this method.
In this process, a woman’s eggs are collected from her ovaries and fertilized with sperm in a lab. Once fertilization occurs, one or more healthy embryos are placed back into the uterus with the hope of achieving a successful pregnancy. The process usually involves hormone injections that stimulate the production of the eggs, frequent monitoring and a minor procedure for both egg extraction and embryo transfer.
Also Read: Understanding the IVF process: step-by-step guide
What Factors Influence the IVF Success Rate?
Globally, the IVF success rate ranges from 30% to 40% per cycle for women under 35. However, this success is not guaranteed and depends on various personal, biological and lifestyle-related factors. Let’s explore what affects IVF success in detail.
1. Age: The Most Critical Factor
Age plays the most defining role in determining the IVF success rate by age. Women are born with all the eggs they will ever have. As they age, both the quantity and quality of those eggs decline, especially after age 35. Older eggs are more likely to have chromosomal abnormalities, which reduces the chances of successful fertilization, implantation and a healthy pregnancy. The given table summarises live-birth rates by age as collated by the USA Facts:
| Age Group | IVF Success Rate (per cycle) | Comment |
| Under 35 | 40%–50% | Highest success due to better egg quality |
| 35–37 | 35%–40% | Good, but starts to decline |
| 38–40 | 25%–30% | Decline more noticeable |
| 41–42 | 10%–15% | Success lowers sharply |
| Over 43 | 5% or less | Very low, often needs donor eggs |
The IVF age limit in India is generally capped at 50 years, though success can be seen even after it.
2. Ovarian Reserve & Hormone Levels
A woman’s ovarian reserve refers to the number of eggs left in her ovaries. One major marker is AMH (Anti-Müllerian Hormone). AMH is produced by small follicles in the ovaries that have the potential to grow and release an egg during ovulation. Here’s how average AMH levels by age correlate with fertility:
| Age | Average AMH Level (ng/mL) | Ovarian Reserve |
| <30 | 3.0–5.0 | Excellent |
| 30–34 | 2.5–4.5 | Good |
| 35–37 | 1.5–3.5 | Fair |
| 38–40 | 1.0–2.5 | Low |
| >40 | <1.0 | Very low |
A person’s AMH may correspond well with their age, while in others, it may not. It’s best to view your results with help from a doctor who can look at the full picture.
To know about the best time to start IVF, Also Read: Best time to start IVF Treatment
3. Number of IVF Cycles
The IVF success rate in the first cycle is typically lower than the cumulative success rate over multiple attempts. Each cycle provides an opportunity for fertilization and implantation, and the body may respond more favourably in subsequent cycles with modified protocols. According to Victorian Assisted Reproductive Treatment Authority (VARTA), the average success of IVF based on the number of cycles is as follows:
- First IVF cycle: ~40% success
- Up to third cycle: ~60% cumulative success
- Fourth and above: Slight increase, then plateaus
Many couples need more than one attempt to achieve pregnancy.
4. Lifestyle & Health Conditions
Chronic conditions can dramatically influence IVF outcomes. Some common IVF failure reasons include:
a. Underlying Medical Conditions
| Condition | Effect on IVF | Estimated Impact on IVF Success |
| PCOS (Polycystic Ovary Syndrome) | May cause immature eggs, irregular ovulation or ovarian hyperstimulation. | Women with PCOS may have up to 15–25% lower success rates per cycle unless managed with personalised stimulation protocols. |
| Thyroid Disorders | Disrupts hormonal balance, affects embryo implantation and early pregnancy. | Even subclinical hypothyroidism can reduce implantation by 20–30% if untreated. Proper TSH control (<2.5 mIU/L) improves outcomes. |
| Diabetes | Affects egg and embryo quality, uterine lining, and increases miscarriage risk. | Poorly controlled diabetes may reduce IVF success by 20–50%, especially if HbA1c >7%. |
| Hypertension (High Blood Pressure) | Impairs blood flow to the uterus and may cause complications post-implantation. | May lower implantation and live birth rates by 10–30%, and increase the risk of preeclampsia and placental issues. |
| Fibroids | Can distort the uterine cavity, blocking implantation; the type and location matter. | Submucosal fibroids can reduce success by up to 50%; however, successful pregnancy with fibroids is still possible if they’re small and monitored closely. |
b. Weight and BMI
BMI stands for Body Mass Index. It is a measure used to determine whether a person has a healthy body weight for their height. Both underweight and overweight women face lower IVF success rates compared to those in the healthy BMI range. Hormones like estrogen are stored in fat. Too little or too much fat can disturb hormonal balance.
- Underweight (below 18.5), Normal weight (18.5 to 24.9), Overweight (25 to 29.9), and Obesity (30 or greater).
- Morbid obesity is defined as a BMI over 35. Class I, II, and III obesity are defined as BMI ranges of 30 to 34.9, 35 to 39.9, and 40 or greater.
- Ideal BMI range: 18.5 to 24.9
c. Smoking, Alcohol & Caffeine
- Smoking damages DNA in eggs, decreases uterine receptivity, and reduces egg count. According to a study published in Reproductive Biology and Endocrinology, the spontaneous abortion rate per pregnancy among smokers can be as high as 21.4 % compared with 16.4 % for non-smokers.
- Alcohol and excess caffeine can disrupt hormones and embryo development.
5. Male Factor Infertility
Sperm quality is just as important as egg quality. It’s not all about the female partner. Around 30%–40% of IVF failures stem from male infertility due to:
- Low sperm count
- Poor motility or morphology
- DNA fragmentation
Fertilization fails if the sperm cannot swim well, attach to or fertilize the egg properly. In such cases, Intracytoplasmic Sperm Injection (ICSI) can improve outcomes by injecting a single sperm directly into the egg.
To know more about Male Infertility, Read: Male Infertility causes and reasons
6. Uterine Health
Even if the embryos are healthy and of good quality, they still need the right environment to implant and grow. If the uterus has structural or functional issues, the chances of implantation drop. This becomes one of the leading IVF failure.
Let’s look at some common uterine conditions that can affect IVF success:
| Condition | Description | Effect on IVF |
| Fibroids | Non-cancerous growths in or around the uterus. | If located inside or pressing on the uterine cavity, they may block implantation or increase miscarriage risk. |
| Polyps | Soft, benign growths on the inner wall of the uterus. | It can interfere with embryo implantation, especially if located where the embryo is meant to attach. |
| Adhesions (Asherman’s Syndrome) | Scar tissue forms inside the uterus, often after surgeries like D&C. | Can distort uterine shape, reduce blood flow and prevent successful implantation of embryos. |
| Thin Endometrial Lining | The inner uterine lining where embryos implant; the ideal thickness is 7–14 mm. | A lining thinner than 7 mm may not support embryo attachment, significantly lowering pregnancy chances. |
7. Embryo Quality
Not all embryos have the same potential to implant and result in a live birth. During IVF, embryos are graded based on their development:
- Day 3 Embryos are typically 6–8 cells.
- Day 5 Embryos, called blastocysts, have a more advanced structure with a fluid-filled cavity and inner cell mass (which becomes the fetus).
Embryologists use specific grading systems to assess the symmetry, fragmentation and cell number of embryos. Poor-quality embryos often fail to implant, even in younger women, which becomes one of the common IVF failure reasons.
8. IVF Lab & Clinic Quality
Not all clinics offer the same success rates. Choose clinics with:
- Certified Embryologists: Trained to handle eggs, sperm and embryos with precision.
- Advanced Lab Technology: Includes incubators, micromanipulation tools and time-lapse imaging.
- Blastocyst Transfer Rates: Clinics with higher Day 5 transfer rates generally indicate better culture systems.
- Cryopreservation Standards: Ensures embryos remain viable during freezing and thawing.
- Success Rate Transparency: Reputable clinics share detailed data, including IVF success rate by age and for first cycles.
Couples should ask for clinic-specific IVF success rates by age before beginning treatment.
How to Improve IVF Success Rates?
Success in In Vitro Fertilization (IVF) depends on many controllable and uncontrollable factors. While some elements, like age or egg reserve, are beyond your control, others, such as lifestyle, underlying health conditions and clinic choice, can be managed to improve the outcome. Let’s discuss the evidence-based techniques that can greatly improve your odds of a successful pregnancy via IVF.
| Factor | What You Can Do |
| Maternal Age & Egg Quality | Consider egg freezing before 35. Use donor eggs for better success after 40 |
| Sperm Quality | Improve with lifestyle changes, avoid heat, and take antioxidants. Use ICSI for severe abnormalities |
| Body Mass Index (BMI) | Maintain a BMI between 20–25. Avoid being underweight or obese |
| Hormone Balance & Medical Conditions | Manage TSH, prolactin, and glucose. Monitor estrogen, LH, FSH and progesterone during the cycle |
| Preimplantation Genetic Testing (PGT-A) | Recommended for women >37 or with recurrent failures. Improves the selection of viable embryos |
| Endometrial Receptivity | Aim for 7–14 mm thickness. Use estrogen, PRP, G-CSF or ERA test to time transfer correctly |
| Stress & Emotional Health | Use yoga, meditation, counselling or support groups to build resilience |
| Avoid Toxins (Smoking, Alcohol, etc.) | Quit smoking and alcohol. Avoid BPA, pesticides and chemicals in cosmetics and plastics |
| Clinic & Protocol Selection | Choose accredited IVF centers with strong success rates. Ensure protocols are tailored to your case |
| Nutrition & Supplements | Eat antioxidant-rich foods. Take folic acid, CoQ10, omega-3s and vitamin D (as advised) |
Conclusion
Increasing your IVF success rate is not a matter of luck. It is about making smart decisions along the way. Age, egg and sperm quality, uterine readiness and lifestyle all play a direct role. With professional guidance, personalized plans and a positive mindset, these decisions can get you big rewards in your chances of a successful pregnancy. So, are you ready to take charge of your fertility journey? At Femcare Fertility, we bring together modern reproductive science with sensitive, individualised care to guide you to your goals.
Schedule your consultation today by calling us at 9967050566 and begin your journey to parenthood with confidence!
FAQs (Frequently Asked Questions)
Question: What causes IVF failure?
Answer: Common IVF failure reasons include poor egg or sperm quality, chromosomal abnormalities, thin endometrium, implantation failure and hormonal imbalance. Conditions like PCOS, thyroid disorders or undiagnosed infections can also affect success. A thorough evaluation helps identify specific IVF failure causes.
Question: Can IVF work on the first cycle?
Answer: Yes, the IVF success rate first cycle can be up to 40–50% in young women with no major fertility issues. However, success may take multiple cycles. Personalised protocols and healthy lifestyle choices increase the likelihood of success early on.
Question: What affects IVF success the most?
Answer: Factors like age, AMH levels, embryo quality, uterine health and underlying conditions such as diabetes, thyroids, PCOS, and high blood pressure affect IVF outcomes. Emotional well-being and choosing the right clinic also impact your chances of a healthy pregnancy.
Question: Can I get pregnant with fibroids through IVF?
Answer: Yes, many women have a successful pregnancy with fibroids. However, large or submucosal fibroids may reduce implantation rates. Removal may be advised before IVF if they distort the uterus or cause symptoms.
Question: What tips for lifestyle tips improve IVF success?
Answer: To improve IVF success, maintain a healthy BMI, eat a nutrient-rich diet, avoid smoking/alcohol, reduce stress and sleep well. Control diabetes, PCOS, thyroids, and blood pressure. These IVF success tips help support better egg quality and uterine health.