Why IVF May Not Work and Why to Continue Trying

For all the energy and cost it takes to do, a failed IVF can feel devastating. And when you’ve got to try several times and still it doesn’t seem to work, is there a reason to keep trying? 

The short answer is: yes. 

The longer answer is: because IVF is a complex procedure with a lot of variables that have to be ideal, or at least very good, success often requires more than one cycle. Everything from egg quality to number of eggs to implantation issues and chromosomal composition all factor into successful treatment. When a round isn’t successful, your doctor looks at the factors and makes some tweaks in order to optimize your chances for the next round. 

For women under 35, the chance of becoming pregnant through sexual intercourse (ie without assistive technology) in any given cycle is about 25%. According to the most recent SART (Society for Assisted Reproductive Technology) data, for women under 35 undergoing IVF, regardless of the reason for IVF,  the chance of becoming pregnant is about 45%. It often takes couples more than one try to become pregnant, and for many of the same reasons that it may take couples more than one round of IVF. 

It’s okay if you’ve had a round fail, or more than one. Don’t despair. According to one study, it takes, on average, about 3 cycles to become pregnant through IVF. After 3 cycles of IVF (for women of all ages), approximately 34-42% were successful.

As technology continues to improve, and as we learn more and more about how to optimize the various factors that lead to pregnancy success, these numbers will continue to get better and better.

Read on and see common factors that contribute to a successful or unsuccessful IVF round. Then consider calling your fertility specialist and trying again.

Why IVF Fails

Conception requires that a healthy, quality egg be fertilized by a healthy, quality sperm. Both have to be defect-free. The sperm have to have good enough motility to make it to the egg. If egg and sperm are good, then fertilization will follow. After fertilization, the fertilized egg implants into the (healthy endometrium in the) uterus, and only then can it mature into an embryo, a fetus and then a baby. What a process it is to get all the pieces working together just right. 

Here are some of the most common causes of IVF failure:

• Embryo quality. Successful IVF starts with good quality eggs and sperm. The IVF procedure joins them to create an embryo that will be implanted in the uterus. Sometimes, though, an embryo will look great in the lab but not implant successfully. It may not be due to any single factor--like a defective uterus or poor-quality egg or sperm.

• Age of the eggs. We know that aging affects eggs, though how isn’t exactly clear. Chronological age doesn’t correlate exactly with the age of eggs, but egg quality tends to be higher in younger women’s eggs. A woman’s fertility decreases about age 35. The implantation rate for women under 35 using her own eggs has an implantation rate of about 45 percent. Women between 40 and 42 have about a 15 percent chance of implantation when using their own eggs. But IVF success rates in older women using younger women’s donor eggs almost equal those of younger women using their own eggs. 
  
  
• Ovarian reserve. Women are born with all the eggs (follicles) they’ll ever have. As age increases, the number of eggs decrease. Every menstrual cycle brings the release of another egg and loss of a group of other potential eggs. This gradually uses up the reserve and, with age, follicles become less and less sensitive to the hormone that stimulates them to grow: follicle stimulating hormone (FSH). The number of eggs, their quality and their sensitivity to stimulation are all important contributing factors to successful IVF.    

• Chromosomal issues. A typical egg and sperm each contain 23 chromosomes for a combined total of 46. More or less than that can lead to problems. As eggs age, chromosomal abnormalities become more likely. It’s estimated that a woman in her mid-40s may have chromosomal abnormalities present in up to 75% of her eggs. (Sperm develop abnormalities, too, but at a much lower rate). 

• These abnormalities are a common cause of miscarriage in both natural and IVF pregnancies. Your fertility specialist may recommend a preimplantation genetic testing (PGT) to see if the correct number of chromosomes is present in your embryonic cells.
  
  
• Lifestyle factors. Lifestyle has a huge impact on fertility. Women often hear about losing weight for fertility, but being underweight can be equally problematic. Eating a variety of nutrient dense foods, exercising moderately and taking prenatal vitamins can boost overall health, hormonal health and the quality of eggs and sperm.
  
  
• Alcohol. You’re already aware that alcohol is harmful to pregnant women. Alcohol is harmful when trying to conceive via IVF as well. Research shows that odds of failed fertilization are nearly 50% higher in men and women who drink more than four drinks per week. Women who drink white wine lower their likelihood of successful implantation (by 22%) as do men who drink beer each day lower their likelihood of successful implantation. Women who drink also experience lower peak estrogen levels and have significantly fewer oocytes during their IVF cycles. 

Why Continue Trying?

Infertility is hard enough. When IVF fails, it can be devastating. But not all is lost. IVF isn’t simple or straightforward but a very complex series of procedures. Expect it to be a process. Expect there to be delays, unexpected issues, meetings with doctors and adjustments to the protocol. 

We’ve discussed some of the most common issues, but in fact there are many reasons that it can take more than one round for a successful pregnancy. Sometimes there aren’t enough eggs produced during treatment (a problem affecting 5-35% of women). Sometimes eggs don’t fertilize, even when they’re healthy. Sometimes eggs and sperm fertilize successfully but for some reason, the embryo doesn’t develop normally. 

Because of the complexity of the issues that can arise, there’s no one size fits all solution. Still, there are some things nearly everyone can try that may impact the outcome. Genetic testing is usually carried out before IVF begins, but not always. For certain patients, genetic and karyotype testing can reveal if chromosomal abnormalities that may be a cause of miscarriage or recurrent miscarriage. The mix of fertility drugs and hormones used in IVF can be modified and dosages can be adjusted. You can change your lifestyle to optimize your outcome. You may decide to opt for an egg/sperm donor, or hire a surrogate. 

When you experience a failure in IVF, don’t get discouraged. Meet with your doctor to do a thorough evaluation of the various factors that went into the previous round, then make changes accordingly. Expect some trial and error. By learning what happened, you can map out a path forward for the next round.