Scientific contribution

Invitro Clinic “Sofia” and Dr. Yavor Vladimirov, MD, are the drivers of innovations in the field of assisted reproduction in Bulgaria. Over 25 years of practice, combined with active participation in the scientific community, make the Clinic a benchmark for modern reproductive medicine.

[fs-toc-omit] Innovations introduced for the first time in Bulgaria:

[FS-toc-H2] 2008

On February 20, 2008, the first baby was born in Bulgaria, conceived by a new method of assisted fertilization, applied by the team of Invitro Clinic “Sofia”, called in vitro maturation (IVM). The baby is named Danaya and was born from a first experience with IVM to parents who have 2 years of sterility and male factor. In comparison, the first IVM baby in England was born in October 2007, and the first IVM baby in Germany was born at the end of 2006. By the time Danaya was born, a total of 300 babies were born in the world using this method. In vitro maturation can be used in the treatment of all forms of infertility, without the need for hormonal stimulation. In this method, the eggs mature outside the body in a special nutrient medium suitable for women with an increased risk of ovarian hyperstimulation syndrome.

Learn more

[FS-toc-H2] 2012

In Vitro Clinic “Sofia” and Dr. Yavor Vladimirov implemented for the first time in Bulgaria Endometrial Receptivity Analysis (ERA®) — the first diagnostic test that determines a unique and personalized time for embryo transfer of each woman. The analysis reveals the timing of the implantation window and leads to personalized embryo transfer (PET) and synchronization based on individually obtained results.

Go to the full article

[FS-TOC-H2] 2017

Dr. Yavor Vladimirov and Dr. Desislava Thacheva created and published “Theory of Cryopreservation of Embryos” — the first theory in the world that provides a scientific explanation for the high success rate after thawing embryos. The purpose of their study is to give a logical explanation related to the benefits of freezing and subsequent thawing of embryos. The benefit of building this hypothesis is that cryopreservation is not only a technology used to store embryos, but also a method of treating embryos. It can improve success rates in couples with reproductive problems. ‍

To the publication

[FS-TOC-H2] 2018

Dr. Yavor Vladimirov and Dr. Desislava Thacheva are authors of the chapter “Present and future of cryopreservation of embryos” in the book “Embryology - Theory and Practice” of the publishing house InTechOpen, a world leader in the publication of scientific literature. In this chapter, the authors review the development of embryo freezing technology and the application of the method, focusing on discussing the arguments for and against freezing, as well as the latest success rate results, comparing them with other major methods of assisted reproductive technology. They also present their point of view on the future application of embryo freezing methods and their place in reproductive medicine.

‍To the book

[FS-TOC-H2] 2019

The team of Invitro Clinic “Sofia” carries out, presents and publishes the first study in Bulgaria, which presents and analyzes the semen parameters of men from the Bulgarian population. For the purposes of this study, 482 men with no data of reproductive problems were included, and the volunteers were divided based on their smoking status and their body mass index. The conclusion from this experiment is that body mass has a huge influence on the concentration of seminal fluid. Smoking does not have a significant statistical impact, but Bulgarian men are found to have lower reproductive capacity compared to men in other countries. ‍

About the study

[FS-toc-H2] 2022

Dr. Yavor Vladimirov and the team of Invitro Clinic “Sofia” are developing an innovative method for controlling ovarian stimulation, using estrone-3-glucoronide in urine and a one-time ultrasound examination — COSSESU. This is a controlled ovarian stimulation that allows visits for the stimulation to be minimized to 1, saving patients time and cost. The method is based on the determination of estrone-3-glucuronide levels in the urine. This is done by the patient himself at home with a small portable apparatus. This innovative stimulation protocol ends with a one-time ultrasound examination by a specialist, as well as determination in the blood of the hormonal levels of estrogens and progesterone. ‍

Article 1

Article 2

Article 3

[FS-TOC-H2] 2023

Dr. Yavor Vladimirov is the first Bulgarian specialist in vitro technologies, under whose editorship a book with authors from different countries is published - “IVF Technologies and Infertility - Current Practices and New Perspectives”. The book presents some modern methods of infertility treatment, which are part of in vitro technologies, with an emphasis on clinical practice. Topics discussed include sperm analysis, ovarian stimulation, and basic methods applied in vitro laboratories. The book also discusses the diagnosis and treatment of the immunological factor of infertility, as well as the relationship between infertility and reproductive age. Publisher is InTechOpen, which are world leaders in the publication of scientific literature with open access.

‍To the book

[FS-TOC-H2] 2024

Dr. Yavor Vladimirov and the team of Invitro Clinic “Sofia” present the first study in Bulgaria that analyzed the levels of Anti-Muller Hormone (AMH) at different ages in 28,016 (twenty-eight thousand and sixteen) women from the Bulgarian population. A prognostic statistical model has also been developed, which can facilitate the application of Anti-Muller hormone in clinical practice and prediction of the reproductive capacity and health of the Bulgarian woman. This research and analysis is aimed at professionals and all stakeholders in the public who can use the information provided to demonstrate their understanding of fertility care. The results of this study could help to shape future public health programs - to improve the effectiveness of infertility treatment.

‍About the study

About Study 2

[FS-TOC-H2] 2024

The team of Dr. Yavor Vladimirov is developing a new method for non-ultrasound monitoring of ovarian stimulation (NUMOS) — an innovative approach in assisted reproduction that allows monitoring of ovarian stimulation without the need for ultrasound examinations and blood tests.

‍About the method

Scientific article

About the study