Approximately 10% of all couples have difficulty in conceiving a baby. The development of In Vitro Fertilization (IVF) technology has dramatically opened up new avenues to have a baby. Improved performance of IVF has almost doubled the live birth rate over the past 25 years, and an 80 – 90 % success rate has often been reached after 3 cycles. Don’t get disappointed if the first cycle fails, there is a good chance in the next cycle. One group of patients – the poor responders – has however posed an enormous challenge for clinicians. With aging, there is an increase in both embryo chromosomal abnormalities and cytoplasmic dysfunction, as well as a progressive reduction in the number of chromosomally normal egg cells that are possible to retrieve. As a result, both embryo quality and quantity is reduced, thus explaining the reason why IVF success is markedly decreased after age 38 – 40. The main reason for a lower pregnancy rate is an increased rate of abnormal chromosome numbers in embryos from older patients. If one normal blastocyst (with normal chromosome numbers) is obtained it has a 50 – 60% chance to implant across all age categories and this is reached with a few eggs if you are less than 30 years old but at age 40 we may need over 10-15 eggs to get one normal blastocyst and at age 40 many more cycles are needed to reach this goal since patients 40 and over often only get 5 – 6 eggs per stimulation cycle and even fewer develop into normal blastocysts. Therefore, we need a technique to get more normal embryos to develop. Many approaches have been tried over the years, but none has worked well. Now, however, treatment with stem cells and stem cell products have been shown to give very promising results.
MESENCHYMAL STEM CELLS (MSC)
In rodents it has been known for the past 10 years that stem cell injections into the ovarian “niche” can restore function after destruction of the ovary with gonadotoxic treatment. Healthy eggs can be retrieved after stem cell treatment of the damaged ovary, fertilized with IVF and fertile offspring can be obtained. Even the fluid in which the stem cells have been cultured has the same capacity. Different sources of stem cells have been tried but the best effect has been obtained with stem cells from connective tissue derived mesenchymal stem cells (MSC) such as amniotic fluid, menstrual blood, placental, umbilical cord, bone marrow, and adipose tissue. Mesenchymal tissue is also what the ovarian cells are derived from.
In humans there are reports of pregnancies occurring in patients who have became post-menopausal after chemotherapy or radiation treatment and then regained menstrual cycles and even fertility after bone marrow transplantation (a rich source of stem cells) have been transplanted. This has been attributed to stem cell factors that can reach the ovaries from the bone marrow, from other surviving stem cells or unknown circulating stem cell factors that can find its way “homing in” to damaged egg cells and restart their function.
PREMATURE OVARIAN FAILURE (POF)
These exciting animal and human studies soon were followed by MSC injection into the ovaries of infertile patients. Edessy et al (2016) first reported a series of 10 patients with premature ovarian failure (POF) where ovaries were injected with autologous bone marrow derived MSC and 2 patients resumed menses and one patient got pregnant and had a term live birth. More studies followed all with a relatively low pregnancy rate of 0 – 10% in POF patients using different sources of MSC from bone marrow, umbilical cord and adipose tissue. The intraovarian MSC injections were mostly given transvaginally but sometimes laparoscopic ovarian injections were necessary since ovaries in POF patients may be very small and difficult to visualize transvaginally. More recently a 57% pregnancy rate has been achieved when the ovarian MSC injections were combined with longer and more aggressive gonadotropin stimulation combined with IVF. This pregnancy rate is quite impressive since the pregnancies were created in POF patients without periods and they would otherwise have an extremely low chance to get pregnant.
POOR RESPONSE IN IVF
When the same ovarian injection technique of MSC was applied to patients with poor response in IVF (only a few eggs retrieved but normal FSH and estrogen levels but low AMH levels) a much more impressive response in egg numbers and embryo quality was seen (30-60%). This improvement in the quality and quantity of the embryos may increase the chances of your own biological baby before going to donor eggs or donor embryos. IVF is not always necessary and a significant number of pregnancies have occurred with no or only clomid stimulation.
MSC AS DRUGS
In the USA the government considers stem cells as drugs and are therefore subject to new drug testing requirements that take years to perform and may cost 200 – 300 million dollars. No pharmaceutical company is prepared to spend this amount of money on having stem cell treatment approved in the USA and therefore the active stem cell treatment has moved outside of the USA mainly concentrated in the Caribbean. Exosome and PRP treatments (see below) are also considered new drugs but the US government has so far been less interested in these treatments.
HOW DOES MSC WORK
How MSC are able to restore damaged tissue in the ovaries is under a very active research. Follicular atresia can occur at any stage of the egg development and result is apoptosis (cell death) of the oocyte. The tumor necrosis factor (TNF family) and its receptors are considered to be the trigger of apoptosis and in a complex interaction between different growth factor atresia and stimulation of follicular growth are controlled by stem cell factors. MSC, exosomes, and PRP all produce growth factors belonging to the transforming growth factors (TGF) family that inhibit apoptosis and stimulate growth and development.
The MSC have two distinct properties, differentiating potential and production of a specific secretome assigned to the ovarian “niche”. MSC are a differentiated stem cell population that have a very low immunogenicity and almost no risk for uncontrolled growth. The differentiation capacity is documented with the ability of MSC to differentiate into various ovarian cell lines. It is widely accepted that the MSC secretome with its paracrine exosomes containing growth factors and cytokines is the most important function of the MSC.
An important component of the function of stem cells is their ability to “homing in” These cells can migrate through-out the body and accumulate in an area of disturbed microenvironment and release factors for tissue repair exactly where the damage or inflammation occurred. In the ovary MSC can differentiate into theca cells, corona radiata cells, granulosa cells that then secretes cytokine and growth factors that stimulate oocyte growth and development. Whether MSC injected directly into the ovarian niche in humans can develop into oocytes is still controversial but many animal studies indicate that this is a strong possibility.
The MSC secretome or MSC exosomes are tiny particles (30 – 150 nm or 1/1000 of a cell size) that are sent out from stem cells, travel in all tissues as messengers and control the function and the performance of all cells in the body just like a conductor controls the symphony orchestra. Exosomes also function in paracrine signaling and is important for anti-inflammatory effects, immune regulation, immunosuppression, anti-apoptosis, and production of factors for anti-fibrosis as well as suppression of oxidative stress. Cell receptors control to which cells these exosomes will be delivered. Both exosomes and stem cells contain a large number of growth factors, cytokines, transcription factors, matrix proteins (that governs the cell structures, function, and signaling), messenger RNA (the blueprint for protein production) and micro RNA (an important intracellular signaling factor). The exosomes from MSC contain the same growth promoting factors as those found in the “parent” cells. Stem cells have a short (3-7 days) active function in the body after infusion where they produce exosomes. Exosomes are more stable and survive for up to a month and induce other stem cells to produce more exosomes identical to the original exosomes. Exosomes can be produced commercially from carefully selected pre-natal tissues, can be frozen and kept at -20° for up to 6 months which means they can be transported on frozen ice, can easily be thawed and are immediately available for use. The fact that they are produced from young peri-natal tissue such as placental or umbilical cord MSC means that they contain factors that are geared toward growth, development and differentiation whereas adult MSC from fat or bone marrow are more aiming for anti-inflammatory or anti-neoplastic responses.
Platlet-rich plasma (PRP) is prepared from that patients own blood and concentrates a multitude of growth factors and cytokines after activation. PRP can augment tissue regeneration, angiogenesis, cell migration, differentiation and proliferation.
Initially in fertility research PRP was used for its angiogenic properties to improve vascularization of cryopreserved transplanted ovarian tissue – a procedure that resulted in a live birth. The next approach was to use PRP in induce menstrual cycles in early post-menopausal women, followed by smaller studies that applied PRP to perimenopausal fertility problems. Now, multiple studies have shown a positive ovarian response after local injection of PRP into the ovary. PRP does not contain the stem cells that have the ability to differentiate into ovarian cells that participate in the formation of the egg cells.
Following PRP injections, elevated FSH levels declined and AMH levels frequently increased with small number of pregnancies reported. A summary of the results up to the summer of 2021 indicated a 10% live birth rate in POF patients and a 28% live birth rate in patients with poor performance in IVF. PRP combined with MSC in controlled ovarian stimulation and IVF significantly improves the results.
Recent studies indicate that different cytokines and growth factors work together and support each other to create a coordinated response. In an experimental study it was shown that MSC and PRP given together was more effective than either treatment alone. A combination of the MSC, exosomes, and PRP may therefore create an optimal effect but no such studies have been reported.
At Friberg Fertility we have been working with stem cell injection into the ovaries since 2018 and had the first pregnancy in 2019. Because of Covid risks the program was put on hold during 2020 but was started up again in 2021. A small number of patients have been treated so far with a pregnancy rate close to 40% and with several patients still pregnant. The intent is to compare embryo quality and quantity in IVF before and after injection of a combination of MSC, MSC derived exosomes and PRP into the ovaries of patients with poor performance in IVF. As a surprise a few spontaneous pregnancies have occurred before the second IVF was performed. Ovarian stem cell treatment is an approach worth trying before an egg or embryo donation is considered.