In this session, Dr. Yanina Samoilovich, Obstetrician-Gynecologist, Fertility Specialist at International Centre for Reproductive Medicine (ICRM), St. Petersburg, Russia has been talking about all the factors that can impact your IVF success like age, sperm and egg quality, uterine and genetics.
Dr Samoilovich started by naming the major influences on IVF success, these include the age of both partners, quality of gametes and embryos, embryo transfer, uterine factor, genetic factors, haematological factors, immunological factors and lifestyle including, BMI, smoking, and stress. Age is one of the most important factors. Each woman has a certain number of oocytes during fetal development, in the 4th month of fetal development, the ovaries have from 6 to 7 million oocytes. At any particular chronological age, the vast majority of the oocytes in the ovary are present as non-growing primordial follicles. Due to the rapid loss of the great majority of the primordial follicles, in the second half of fetal life at birth, only from 1 to 2 million primordial follicles remain. After birth, this high rate of follicle loss slows down somewhat, at least from 300 000 to 400 00 primordial follicles remain. During a woman’s reproductive years, their continued and gradually accelerated decline causes the number to drop below 1000 at the time of menopause. Along with the decrease in follicle number, oocyte quality also diminishes at least after 31, when fecundity gradually decreases.
It’s also important to remember the paternal age. Paternal age of more than 50 years old is associated with a high percentage of epigenetic changes, a higher percentage of DNA fragmentation and DNA mutation in the sperm and impaired spermatogenesis. It decreases the success rate of IVF programs, there is also a higher risk of some diseases in offspring like Autism, psychological disorders like Bipolar disorders and so on.
Quality of oocytes & sperm – treatment options
There are some protocols to improve the quality of eggs before stimulation. For patients with Polycystic ovary syndrome (PCOS), there are some drugs as Metformin or Myo-inositol, which have a positive impact on the egg quality in this group of patients. Another option is to give androgens to women with lower ovarian reserve to try to improve the receptivity and ovarian response. It’s very important to treat endometriosis before the stimulation, this is a disease with many steps of pathogenesis. Some drugs help with releasing the process of oxidative stress and alteration in the oocytes. Regarding sperm quality, some treatment options are available, such as treatment with antioxidants, and vitamins to decrease DNA fragmentation.
Embryo factor
The quality of embryos is determined by the quality of gametes. The better embryo patients have, the more chances for a pregnancy they have. A special classification of embryos on day 5 includes cell number, percentage of fragmentation and nucleation as well as alterations and cell division moment.
The embryologist usually checks the embryos on day 3, they should have at least 8 cells, and then on day 5 at the blastocyst stage. A good quality embryo means it’s good or intermediate according to the classification, it has to have genetically healthy parents whose karyotype is checked with a blood test. If the embryo is PGT-A tested, there is a lot more information on its quality.
One of the key factors to having a good quality embryo is also a good IVF lab. Not only experienced embryologists but also the best equipment and the latest technology can result in a better quality embryo as well as higher pregnancy rates.
Uterine factor
Nowadays, thanks to ultrasound and MRI, gynaecologists can easily find problems in terms of the uterus. There can be congenital abnormalities, which can cause an implantation failure, but also newly acquired anomalies such as polyps, myomas, adenomyosis, or adhesions in the cavity. Another difficult condition called chronic endometritis can be determined only by hysteroscopy and histological examination of the endometrium. Sometimes, as a result of chronic inflammation, thin endometrium can occur.
The optimal geometrical thickness is between 7 and 12 mm, and it should have a trilaminar morphology on ultrasound on the day of embryo transfer. The endometrial environment is very important and a high concentration of progesterone, for example, on the day of the trigger administration during an ovarian stimulation can cause an incorrect endometrial receptivity on the day of embryo transfer. Hydrosalpinx is a reason for chronic inflammation in the abdomen, and this inflammation process can reduce pregnancy rates by 50% and increase the risk of miscarriage by 50% as well. If a patient has mono or bilateral hydrosalpinx, it has to be removed by laparoscopy before an IVF cycle. Myomas can have a negative impact because they can alter the blood flow and increase the contractility of the uterus. Submucosal myomas can deform the cavity.
Some tests, such as the ERA test, help to predict the window of implantation. EMMA and ALICE tests can determine the endometrial microbiome and help to see if a patient has endometritis or not.
Embryo transfer – final IVF step
This final step is a very important step of the whole IVF procedure, and it can take a couple of seconds to a few minutes. The main factors that can affect embryo transfer are the doctor’s experience, ultrasound guidance, catheter type, gentle manipulation, the presence of blood, and rest after the transfer.
Haematological aspects (clotting alterations)
Thrombophilia can alter the coagulation cascade, and someone can develop microthrombosis, which can harm what will be the placenta of the baby. They can create blood clots and alter the blood flow between the baby and the mother, so sometimes, it can stop a heartbeat because of micro infections caused by those blood clots.
Thrombophilia can also cause, for example, heart attacks, thromboembolisms and so on. There is a low percentage of women who miscarry because of thrombophilia, and those can be treated with heparin and aspirin, which helps to prevent the formation of blood clots.
Immune factors
Women with recurrent pregnancy loss or thrombosis in their history should be checked for a difficult condition called antiphospholipid syndrome. NK cells should also be examined in such situations, NK cells are a type of lymphocyte circulating in peripheral blood. Immune cells that share similar phenotypic characteristics but are poor killers populate the uterine lining at implantation and during early pregnancy when the placenta is established. The functions of uterine NK cells are still unknown, but some available data shows that they play a role in regulating placentation and other elements of the decidua and invading trophoblast cells. Even though there is a lack of scientific proof, a lot of tests and treatment options are offered to women who undergo IVF or those experiencing recurrent miscarriages. However, it is important to remember that it still lacks evidence and should be carefully evaluated before such treatment can be offered.
Lifestyle factors
Some factors depend on every patient personally. The first one is body mass index (BMI). The optimal BMI is from 20 to 24. Being underweight can cause a lack of ovulation, while obesity can increase the risks of complications during pregnancy, such as gestational diabetes, hypertension disorders preeclampsia and pre-term birth. Moreover, some data shows that being underweight or overweight can affect oocyte quality. Moderate physical activity and exercise decrease the risk of miscarriage and increase the chance of success among women who undergo IVF programs. A minimum of 1-hour exercise 3 times a week improves implantation rates and pregnancy and reduces the risk of miscarriage.
It’s necessary to understand some facts and the possible harm that caffeine can cause. It’s one of the most psychoactive components, and it is found in more than 60 plants, it exists in saliva, and breast milk. Caffeine is also present in tea, chocolate, and energy drinks, but it’s still unclear if caffeine impacts the chances of pregnancy. Therefore, experts advise limiting caffeine if you are trying to conceive and during pregnancy.
Another thing is alcohol, it’s clear that heavy drinking increases the time it takes to get pregnant and can affect a developing baby’s health. It’s best to avoid alcohol when trying to conceive, and those who try to conceive should limit alcohol to no more than 15 units a week.
Couples that deal with infertility, very often are very overstressed, which in the end decreases their chances of success, and that’s why it’s important to also have a consultation with a psychologist who can help with finding ways to deal with stress and their ongoing fertility treatment. In conclusion, one of the main principles of treating patients is to individualize the characteristics of each patient and adapt medical treatment to the individual characteristics of each patient.
