In assisted reproduction, every stage of the treatment significantly impacts the chances of achieving a successful pregnancy. One of the most crucial phases is embryo development to the blastocyst stage, which is considered a strong indicator of implantation viability. But what percentage of fertilized eggs actually make it to this stage?
In this blog, we’ll answer that question with accurate data, explain the factors that influence embryo development, and how techniques like egg freezing, egg donation, and receiving care at a fertility clinic like Ingenes can make a significant difference. We’ll also explore the main causes of female infertility that may impact this process.
After fertilization, the embryo undergoes several cell divisions. About five to six days after fertilization, the embryo can reach the blastocyst stage, where it forms a fluid-filled cavity and begins to differentiate into cells that will become the baby and others that will form the placenta.
This stage is critical because only embryos that reach the blastocyst stage have a high probability of implanting in the uterus and developing successfully during pregnancy.
On average, between 40% and 60% of fertilized eggs reach the blastocyst stage, although this number can vary depending on several factors such as:
In younger patients using their own eggs without complications, percentages can exceed 60%. However, in women with low ovarian reserve or over the age of 38, this percentage may decrease significantly.
Egg quality is one of the most determining factors. As a woman ages, both the quality and quantity of her eggs decline. This is why many women opt for egg freezing at an early stage in their reproductive life to increase their chances of success in the future.
Although female fertility is often the focus, a large portion of embryo development issues can also be related to sperm. It’s important that both partners are evaluated at a fertility clinic to get a complete diagnosis.
Certain causes of female infertility, such as polycystic ovary syndrome (PCOS), endometriosis, hormonal disorders, or uterine abnormalities can affect the quality of the eggs or the environment where embryos develop, lowering success rates.
At Ingenes, we use specialized technologies at each stage to optimize outcomes. Through state-of-the-art embryo culture systems and continuous monitoring, we achieve higher development rates to the blastocyst stage.
Additionally, treatments such as enriched culture media, low-vibration incubators, and techniques like PICSI or ICSI enhance fertilization and embryo quality.
Yes. Egg freezing is an excellent option for women who want to postpone motherhood without compromising egg quality. When these eggs are used later, they have a strong potential to develop into viable embryos if preserved at an optimal stage.
On the other hand, egg donation, especially for women with causes of female infertility such as premature ovarian failure or poor egg quality, offers a greater chance of embryos reaching the blastocyst stage. This is because donor eggs come from young, healthy women, evaluated under strict criteria at an experienced fertility clinic like Ingenes.
The decision to transfer an embryo on Day 3 or wait until it reaches the blastocyst stage (Day 5) depends on:
In general, transferring a blastocyst offers higher implantation rates, as long as there are at least one or two high-quality embryos.
Choosing a fertility clinic with experience and advanced technology is key. At Ingenes, we personalize every treatment based on your specific needs—whether you’re considering egg donation, egg freezing, or want to identify possible causes of female infertility that affect your reproductive health.
Hormone testing for AMH (Anti-Müllerian Hormone) and an ultrasound to count antral follicles are essential tools to estimate how many eggs you can obtain and the expected rate of embryo development to the blastocyst stage.
From personalized hormone treatments to advanced procedures like ovarian rejuvenation, high-complexity reproductive medicine can help you achieve better results.
At Ingenes, we have over 20 years of experience helping thousands of women and couples fulfill their dream of having a baby. We offer comprehensive solutions that include:
Our lab is also equipped to maximize success rates, helping a higher percentage of fertilized eggs reach the blastocyst stage with high viability.
Although not all fertilized eggs reach the blastocyst stage, each step of the treatment can be optimized to improve your chances. Egg quality, causes of female infertility, lab conditions, and the medical decisions made at a quality fertility clinic all play a role.
Whether you’re considering egg freezing, egg donation, or simply want to better understand your options regarding the causes of female infertility, Ingenes is here to help you.
Schedule your consultation and discover how we can increase your chances of success. Every embryo is a possibility—and with the right support, it can become the life you’ve been dreaming of.
