Your Trusted Fertility Clinic In New York, NY

Answer:

If you’ve undergone in vitro fertilization (IVF) and didn’t achieve a successful pregnancy, you may be wondering why. It’s important to know that IVF outcomes can be unpredictable, but there are factors that can affect your chances. Let’s explore some common reasons for IVF failure in simpler terms.

1. Age: A woman’s age is a significant factor in IVF success. Generally, women under 35 have a higher chance of getting pregnant through IVF, around 35-40% per embryo transfer. However, this success rate decreases as women get older. For women in their mid-forties, the success rate drops to under 5%. This decline is mainly because the quality of eggs decreases as women age, affecting their ability to develop normally.

1. Egg/Embryo Competency: Apart from age, the quality and competency of embryos also affect IVF success. The quality of eggs and embryos is influenced by a woman’s age. However, for older women or those with fewer eggs, the specific IVF protocol used to stimulate the ovaries becomes crucial. A more aggressive approach may be needed to maximize the chances of success. Previously, it was thought that the uterus was better for embryo development than the lab environment. So, early-stage embryos were transferred to the uterus based on their appearance. However, we now know that embryos that have progressed further in development are more likely to be successful. Embryos that don’t reach the blastocyst stage within 5-6 days after fertilization are considered less competent and not suitable for transfer. Additionally, Preimplantation Genetic Sampling / Testing (PGS/T) allows us to check the chromosomes of embryos. This technique helps select the most competent embryos for transfer, especially for older women, those with fewer eggs, repeated IVF failures, and recurrent pregnancy loss.

1. Number of Embryos Transferred: Some people believe that transferring more embryos increases the chances of success. While this may have some truth, it’s essential to know that if the problem lies with the ovarian stimulation protocol, transferring more embryos won’t solve it. Also, transferring more embryos doesn’t fix issues related to embryo implantation dysfunction, such as anatomical or immunologic problems. Moreover, multiple embryos can lead to higher-order multiple pregnancies, which pose risks. To minimize these risks, it’s generally recommended to transfer a maximum of two embryos, or even just one, especially when using eggs from young women.

1. Implantation Dysfunction (ID): Implantation dysfunction is often overlooked as a cause of unexplained IVF failure, especially in young women with normal ovarian reserve and fertile partners. Failure to identify and address these issues can result in repeated IVF failures. If transferring competent embryos repeatedly fails to result in a viable pregnancy, implantation dysfunction should be considered. The most common causes include:

1. 1. Thin Uterine Lining: When the lining of the uterus is too thin, it can affect the embryo’s ability to implant and grow.
   2. Surface Lesions in the Uterus: Polyps, fibroids, or scar tissue in the uterus can interfere with embryo implantation.
   3. Immunologic Implantation Dysfunction (IID): Sometimes, the immune system can mistakenly attack the embryo, preventing successful implantation.
   4. Endocrine/Molecular Endometrial Receptivity Issues: Hormonal or molecular issues in the uterine lining can impact the embryo’s ability to attach and develop.
   5. Ureaplasma Urealyticum (UU) Infection: This infection in the cervical mucous and uterine lining can lead to unexplained early pregnancy loss or IVF failure. Both partners should be tested and treated if positive to prevent transmission.

Certain causes of infertility are difficult or impossible  to reverse, e.g.; advanced age of the woman, severe male infertility, and immunologic implantation dysfunction associated with certain specific genetic factors.

Understanding the common factors contributing to IVF failure can help you have informed discussions with your doctor and make decisions for future attempts. Factors like the number of embryos transferred and implantation dysfunction play significant roles. While success cannot be guaranteed, knowing these factors can guide you in maximizing your chances and addressing potential issues.