In vitro fertilization (IVF) is one of the most significant medical advances in the field of assisted reproduction. However, the success of this treatment depends on numerous factors that must be considered to optimize results. In this article, we explore the key elements for achieving satisfactory outcomes in IVF and how to address the most important variables.
Synchronization Between the Embryo and the Endometrium
One of the fundamental bases for IVF success is transferring a high-quality embryo with a normal genetic makeup (euploid) into a receptive, perfectly synchronized endometrium. During ovarian stimulation, elevated hormone levels can cause desynchronization between the embryo and the endometrium, which negatively impacts implantation rates.
Today, deferred (frozen) transfers are increasingly common thanks to advances in embryo vitrification. According to recent data, 64.5% of transfers are now performed as frozen transfers, compared to 35.5% as fresh transfers. This improves success rates by allowing the endometrium to reach an optimal state before transfer.
Maternal Factors: The Influence of Health Status
- Obesity: although it does not directly affect egg quality or fertilization rates, it is associated with a higher risk of miscarriage and obstetric complications. Women with a body mass index (BMI) over 30 have a 22% miscarriage rate after transfer of a euploid embryo.
- Maternal Age: when transferring a genetically normal embryo, the mother’s age does not have a significant impact on outcomes.
- AMH Level: although very high anti-Müllerian hormone levels (>6.2 ng/ml) in women with polycystic ovaries can complicate outcomes, in general there is no direct relationship between moderate AMH levels and worse results.
Embryonic Factors: Quality and Development
Embryo quality is crucial to IVF success. Transferring a single euploid embryo helps minimize risks and improves obstetric outcomes. In addition, embryo kinetics, or the speed of development, is a key indicator: embryos that reach the blastocyst stage on day 5 have higher success rates compared to those that reach it on later days (day 6 or 7).
Uterine Factors: Preparation and Optimal Conditions
- Endometrial Thickness: a thickness of between 4 and 12 mm is sufficient to achieve good results when transferring a euploid embryo. However, the endometrial pattern can influence the implantation rate.
- Adenomyosis: this condition reduces pregnancy rates by 30%. Treatment with GnRH analogues for 2-3 months has been shown to significantly improve the chances of success.
- C-Section Scars: the presence of an isthmocele, a fluid accumulation in the scar, can alter the endometrial microenvironment. In these cases, surgical correction is recommended before proceeding with the transfer.
- Natural Cycle vs. Substituted Cycle: performing the transfer in a natural cycle, when the woman has regular cycles, reduces associated risks such as hypertension, preeclampsia, and postpartum hemorrhage. This approach is safer for both mother and baby.
Optimizing Treatment at Clínica Fertia
At Clínica Fertia, we understand that every patient is unique. That’s why we personalize assisted reproduction treatments to maximize the chances of success. We pay close attention to factors such as embryo quality, uterine preparation, and each patient’s specific characteristics, ensuring a comprehensive and effective approach.
Success in in vitro fertilization treatments depends on multiple interconnected variables. A thorough evaluation of maternal, embryonic, and uterine factors, combined with advanced technologies and personalized strategies, ensures the best possible results. At Clínica Fertia, we work to turn the dream of becoming parents into reality.
Want to become a mother? Book a consultation with our fertility specialists to explore the best options for you.
References
- Bellver J. BMI and miscarriage after IVF. Curr Opin Obstet Gynecol. 2022 Jun 1;34(3):114-121.
- Cimadomo D, Soscia D, Casciani V, Innocenti F, Trio S, Chiappetta V, Albricci L, Maggiulli R, Erlich I, Ben-Meir A, Har-Vardi I, Vaiarelli A, Ubaldi FM, Rienzi L. How slow is too slow? A comprehensive portrait of Day 7 blastocysts and their clinical value standardized through artificial intelligence. Hum Reprod. 2022 May 30;37(6):1134-1147.
- Mathyk B, Schwartz A, DeCherney A, Ata B. A critical appraisal of studies on endometrial thickness and embryo transfer outcome. Reprod Biomed Online. 2023 Oct;47(4):103259.
- Ge L, Li Y, Zhou J, Zhao X, Chen X, Wang W, Li Z, Ge P, Cui L. Effect of different treatment protocols on in vitro fertilisation/intracytoplasmic sperm injection (IVF/ICSI) outcomes in adenomyosis women: a systematic review and meta-analysis. BMJ Open. 2024 Jul 18;14(7):e077025.
