Factors That Influence IVF Success Rates: What You Need to Know
▫️WRITTEN BY DR RAELIA LEW
For many women and couples, IVF treatment represents a hopeful path to parenthood. Yet, navigating the journey can be emotionally and physically demanding especially when faced with uncertainty around success rates. Understanding the factors that influence IVF outcomes can empower patients to make informed decisions and take proactive steps to improve their chances.
WHM are proud to provide our patients with their best chance of IVF success through multifactorial influences. We strive to optimise every point around IVF success, from our CREI lead specialist fertility team, to our world class leading laboratory, and everything in between.
This article offers clear, evidence-based insights into IVF success rates, including how they're measured, what influences them, and how WHM’s affiliated IVF laboratory, Melbourne IVF, compares to national averages.
Whether you're just beginning your fertility journey or already undergoing treatment, this guide is designed to help you set realistic expectations and feel supported every step of the way.
UNDERSTANDING IVF SUCCESS RATE STATISTICS
HOW ARE SUCCESS RATES MEASURED?
IVF success rates can be reported in several different ways. For this reason, when you are new to IVF treatment, you may find reporting confusing.
Success may be measured per cycle of IVF initiated, which represents the percentage of cycles that result in a pregnancy or live birth.
Alternatively, rates can be calculated per embryo transfer, showing the success rate based on the number of embryo transfers performed.
Cumulative IVF live birth rates provide another perspective, indicating the likelihood of success over multiple cycles of IVF or after multiple embryo transfer attempts.
It's important to distinguish between pregnancy rates, which simply indicate a positive pregnancy test, and live birth rates.
Many women who have an IVF embryo transfer become pregnant, but unfortunately not all pregnancies result in the birth of a baby. Some pregnancies are biochemical, some may result in an ectopic pregnancies, others may result in pregnancy loss or miscarriage.
This is why Live Birth rate is the most meaningful measure of IVF success as this represents the ultimate goal of IVF; taking home a healthy baby.
WHY CLINIC-SPECIFIC DATA MATTERS
Success rates vary significantly between IVF clinics due to complex differences in IVF care. Specialist attitudes, strategy, experience and acumen, protocol planning and management, the use or absence of sophisticated technologies, and patient demographics can all have significant influences on IVF success rates. This variation makes reviewing clinic-specific data essential for patients who want to choose a provider aligned with their needs, circumstances and aspirations to achieve success.
WHM partners with Melbourne IVF, Melbourne’s leading IVF laboratory when it comes to laboratory factor influenced IVF success rates.
AVERAGE IVF SUCCESS RATES IN AUSTRALIA
IVF success rates vary considerably by age. In IVF, we say age is queen. This is because female age is arguably the most important biological variable influencing IVF success rates. Women under 35 have a live birth rate of >50% per completed IVF cycle in our laboratory, representing the highest possible success rates. This refers to live birth rate from one egg collection and resultant embryo transfers.
This is considerably higher than national average success rates which come in closer to 40%.
For older women success rates fall considerably. Women over 40 face the greatest challenges, with a success rate of 10-20% or less per cycle.
Melbourne IVF success rates are publicly reported year on year and are published on our Melbourne IVF website, Your IVF Success website and are included in ANZARD date reporting.
WHM IVF SUCCESS RATES COMPARED TO NATIONAL AVERAGES
WHM (Women's Health Melbourne) partnering with Melbourne IVF, consistently performs above the national average across all age groups. This superior performance demonstrates the clinic's commitment to advanced protocols, personalised care, and cutting-edge technologies that optimise patient outcomes.
Our CREI lead service is second to none delivering the highest level of care for our patients.
WHM IVF success rates compared to national averages
HOW AGE IMPACTS IVF SUCCESS RATES
Age stands as one of the most significant factors in IVF success, with biological changes creating increasing challenges over time. Egg quality and quantity naturally decline with age, with this decline becoming more pronounced after 35. Older eggs are more likely to have chromosomal abnormalities, which reduces implantation rates and increases the risk of miscarriage.
For women facing diminished ovarian reserve or poor egg quality, donor eggs may be considered as an alternative. This option can offer significantly higher success rates, providing hope for those who might otherwise face very low chances of success with their own eggs.
OTHER PATIENT FACTORS THAT INFLUENCE IVF SUCCESS
MEDICAL FACTORS THAT INFLUENCE IVF SUCCESS
Several underlying health conditions can significantly impact IVF outcomes and require careful management. Endometriosis can affect both egg quality and implantation success, though surgical or medical management may help improve outcomes. Hormonal imbalances, including conditions like PCOS or thyroid dysfunction, can disrupt both ovulation and endometrial receptivity, making conception more challenging.
Diabetes presents another consideration, as poorly controlled blood sugar levels can impair fertility and negatively affect pregnancy outcomes. Optimising these conditions before and during treatment proves crucial for maximising the chances of IVF success.
Weight is another important factor: those under or overweight have expected lower age matched success rates in IVF.
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LIFESTYLE FACTORS THAT AFFECT IVF SUCCESS
Your lifestyle choices play a powerful role in fertility outcomes and can significantly influence IVF success rates. Weight management is particularly important, as both obesity and being underweight can affect hormone levels, egg quality, and implantation success. Smoking presents serious risks, reducing ovarian reserve and increasing the likelihood of miscarriage.
Alcohol and drug use can impair fertility and negatively impact embryo development, making lifestyle modifications essential. Adopting a healthy lifestyle that includes balanced nutrition, regular exercise, optimised weight with a healthy BMI < 25, and effective stress management can enhance IVF outcomes and improve your overall health during the treatment process.
Listen to our podcasts with Dr Alexandra Harvey about lifestyle factors that influence your fertility.
TREATMENT VARIABLES THAT AFFECT IVF SUCCESS
Several aspects of the IVF process itself can influence success rates and require careful consideration. The number of embryos transferred represents one such factor—while transferring more than one embryo may increase the chances of pregnancy, it also raises the risk of multiple births with associated complications.
Embryo quality plays a crucial role, as high-grade embryos demonstrate much higher rates of successful implantation. Despite fertility challenges couples face, a couple is predicted to be able to create better quality embryos using a first class IVF laboratory. We see considerable differences in IVF success rates between basic and high class IVF laboratories. This difference is the most profound for patients with complex medical circumstances.
Genetic testing, known as PGT-A, offers another valuable tool by screening embryos for chromosomal abnormalities, which can improve embryo selection and reduce miscarriage risk.
Protocol types matter significantly, with individualised stimulation protocols tailored to your specific ovarian response helping to optimise egg retrieval outcomes. The timing of transfer also influences success, as some patients benefit more from frozen embryo transfers after careful endometrial preparation rather than fresh transfers.
HOW TO IMPROVE YOUR CHANCES OF IVF SUCCESS
Taking proactive steps can help maximise your chances of IVF success. Choosing the right CREI certified IVF specialist, working with the best clinic forms the foundation of your treatment.
You should look for transparent success rates, CREI certified fertility specialist leaders, personalised care approaches, and access to them most advanced and emerging technologies. Getting a thorough medical evaluation before beginning treatment allows you to address any modifiable factors associated with underlying conditions that might impact your success.
Adopting a fertility-friendly lifestyle provides another avenue for improvement. This includes maintaining a healthy weight, avoiding smoking completely, excluding toxins and unnecessary medications, ceasing potentially harmful supplements and developing effective stress management strategies. For patients who have experienced previous failed IVF cycles or miscarriages, considering genetic testing of embryos (PGT) may provide valuable insights and improve outcomes.
Throughout this process, staying informed and emotionally supported proves essential. IVF can be successful in a single cycle, but for many patients serial treatments are needed. While this is expected and normal, IVF represents a significant journey, and having access to both education and emotional support can make a substantial difference in your experience and outcomes.
CONCLUSION
IVF success emerges from a complex interplay of many factors. Patients age, health, lifestyle, and treatment choices can all make a difference. While some factors remain beyond your control, choosing the right specialist and clinic is within your power. Many important factors influential to your IVF success can be optimised with the right guidance, laboratory power and comprehensive care approach.
At WHM, we believe in empowering patients with knowledge and providing compassionate support throughout their fertility journey. Our experienced team stands ready to help you understand your unique fertility profile and develop a personalised treatment plan that maximises your chances of success.
We choose to partner with Melbourne IVF, Melbourne’s leading IVF laboratory when it comes to success rates, optimising every aspect of IVF care for our patients, from clinic to laboratory.
Ready to take the next step? Schedule a consultation with Dr Raelia Lew at WHM to explore your options and begin your journey with confidence, knowing you have expert support every step of the way.
Written by Dr Raelia Lew
Dr Raelia Lew is the Medical Director of Women’s Health Melbourne. Dr Raelia is a Royal Australia and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) Board Certified CREI Fertility Specialist, and is President Elect of the Australia and New Zealand Society of Reproductive Endocrinologists and Infertility Specialists(ANZSREI).