IVF or in-vitro-fertilization is one of the many treatments developed to help couples conceive a child. It is a type of assisted reproductive technology (ART) that combines both medicines and surgical procedures to help the sperm fertilize an egg and then aid the implantation of the fertilized egg in a woman’s uterus.
IVF includes multiple steps, and it may take months to complete the entire process. While for some women, it may work in the first try, others might require to undergo the IVF process more than once to get pregnant. This is because each woman’s body is different, and also, IVF’s success rate depends on several factors.
IVF Success Factors
Although IVF is a complex process, and it certainly increases your chances of being artificially pregnant, some factors affect its success rate in women:
Age is an important factor when considering getting pregnant through IVF. Usually, younger women – women under 35 – have higher chances of IVF success since this is the period when women are the most fertile. While women with no documented infertility issues generally have a 20% IVF success rate, for women who face problems like a genetic disease, low count of eggs, infertility issues of their partner, the IVF success rates would be as outlined by the CDC (Centers for Disease Control):
- Women under 35 years of age have higher success rates as compared to those who are above 35 years.
- If a woman under 35 has never conceived before, her chances of conceiving through IVF is 32%.
- If a woman under 35 has had a child before, her chances of getting pregnant through IVF is 37%.
- If a woman is in her 20s, she has a 34% chance of the IVF cycle to work with two or more than two children.
According to further research by CDC and the Society for Assisted Reproductive Technology (SART), the IVF success rates for women over 40 are:
- For a 40-year-old woman, there’s a 20% chance for the IVF cycle to work and 14% if she opts for live birth.
- For a 41-year-old woman, the chance of IVF to work stands at 15% and 10% for live birth.
- For a 42-year-old woman, the probability for IVF to work is 12% and 7% for live birth.
- For a 43-year-old woman, the IVF success rate is only 8%, and there are 3% chances of live birth.
- For a 44-year-old woman, the chances of IVF success stand at 6%, while the probability for a healthy live birth is only 3%.
- Women over 45 and above have only a 3% chance of getting pregnant via IVF and a meager 1% chance for live birth.
Previous pregnancy or miscarriage
The IVF success rate is much higher if a woman’s previous pregnancies were successful and with the same partner. On the contrary, for women who have faced prior miscarriage once or multiple times, the chances of IVF treatment to work are lowered significantly. In such a case, the woman or couple would first require the doctor to identify the cause of recurrent miscarriage and determine how it would affect the IVF process.
Fertility problems, both in women and men, have a significant bearing on the IVF success rate. In women, fertility issues like uterine abnormalities, exposure to DES, or fibroid tumors lower the chances of IVF success, whereas, in men, low sperm count also reduces the IVF success rate.
Furthermore, the chances of IVF being a success also depends on the ovulation cycle. So, ovarian dysfunction, like high FSH levels (contributing to a low ovarian reserve) reduces the probability of IVF success. If both the partners are infertile, it is vital to consider the duration of time for which they have been infertile. The longer the term of infertility, the lower are the chances of IVF success.
Types of fertility problems that are usually responsive to IVF include:
- Low sperm count
- Ovulation issues
- Fallopian tube blockages
Fertility issues that are less responsive to IVF include:
- Uterine abnormalities
- Fibroid tumors
- Ovarian dysfunction
- Long term infertility
- Dual infertility factor, wherein both partners face different infertility issues.
The quality of donor eggs/sperm
If a woman is over 35 or 40, the IVF success rate increases with the use of donor eggs. However, when considering using donor eggs from another woman, it is essential to determine that the quality of eggs is good.
Also, the age of the donor is another essential consideration (women between 20-35 have the best quality eggs). Hence, using donor eggs from younger women usually increases the chances of pregnancy through IVF for women over 40. As for the sperm, it helps if the man has a healthy and high sperm count with good motility.
Certain lifestyle habits also significantly impact the chances of IVF success. For instance, smoking is detrimental to fertility in both men and women, and women who smoke require a high dosage of fertility drugs for ovary stimulation. Also, smokers have a lower implantation rate than those who don’t smoke.
Another factor that affects the IVF success rate is the weight of a woman. In underweight women, their body weight may adversely impact the absorption of fertility medicines and lower their ability to carry a baby through the entire pregnancy term. Likewise, women who are overweight have an increased risk of miscarriage. So, it is essential to maintain a healthy body weight to ensure the chances of IVF success.
Does embryo quality affect IVF success?
Although numerous factors affect IVF success, embryo quality also plays a crucial role in determining the chances of IVF success. In fact, a majority of all miscarriages occur due to abnormalities in the embryo. Hence, when considering IVF treatment, the chances of success largely depend on transferring the best quality embryos into a woman’s uterus. This is where fertility centers and embryologists have a pivotal part to play. Embryologists must select which embryos to transfer to the uterus and which to freeze and store for future use (a second chance at IVF).
Embryologists monitor the embryos and grade them to determine which embryos are the healthiest and can result in a successful pregnancy before choosing which embryos to transfer at the cleavage or blastocyst stage.
Does the IVF laboratory play a crucial role in IVF Success?
Just as the embryologist plays a pivotal part in determining IVF success, the embryo laboratory is also a crucial part of the entire process. After all, it is the “engine room” of the fertility clinic where the embryos are prepared for implantation. The fertilization occurs in the IVF lab. The embryos are cultured there before transfer. It involves highly complex and sophisticated procedures like genetic testing, assisted hatching, and intracytoplasmic sperm injection (ICSI).
Although often overlooked, the quality of the ART laboratory is one of the most important determinants while choosing a fertility clinic. Some clinics may have an in-house lab, while others may outsource this task to a fully equipped laboratory. There are also full-service IVF labs that can safely freeze and store embryo, sperm, and eggs.
No matter which fertility clinic you choose for your IVF treatment, you must always insist on receiving detailed information about the IVF laboratory as it can make or break your IVF success rate.
How successful is IVF?
As mentioned earlier, the success rate for IVF depends on multiple factors, including the age of the woman, infertility issues (if any), duration of infertility, sperm quality, donor egg quality, embryo quality, and the IVF lab facilities. Usually, the IVF success rate is higher when frozen embryos are used as compared to using fresh embryos. Also, the success rate is higher in younger women.
The bottom line is, nothing concrete can be said about the IVF success rate. It differs from person to person, including a whole range of external and internal factors. So, it’s best to choose a specialized fertility clinic and excellent gynecologist who can assist you in getting pregnant via IVF.