Until shortly before implantation in the uterus, the egg, or the early embryo, is surrounded by a membrane called the zona pellucida. The hatching of the embryo is the process during which the embryo leaves this egg membrane. This natural process, which ends when the zona pellucida ruptures, is an important step towards the implantation of the released embryo.
It is possible that under certain conditions the embryo cannot leave the egg membrane. This prevents implantation, and thus, pregnancy. The reason for this problem may be a particularly thick egg membrane, for instance, or a hardening of the egg membrane, which can be observed especially in the eggs of older women or in frozen eggs. However, it is possible that the egg membrane may be hardening during the cultivation of the egg, which is necessary for in vitro fertilisation (IVF). The latest and safest method for facilitating the hatching of the embryos (assisted hatching) is the application of a diode laser, which allows for a non-touch, precise reduction of the zona pellucida.
Cervical mucus is produced by the glands in the cervix and the vagina. This mucus essentially has two functions:
Protection against germs: Mucus forms a kind of block in the cervix. This creates a barrier that is difficult for germs to penetrate. The uterus is thus better protected against infections.
Transport medium for sperm: The consistency of cervical mucus determines whether a man’s sperm can make its way through the vagina and into the uterus.
The hormone released from follicle-stimulating hormone (FSH), oestrogen and luteinising hormone (LH) not only regulates egg maturation and ovulation, but it also changes the consistency of the cervical mucus. During the course of the menstrual cycle, it is fluid and clear on the fertile days around ovulation. In addition, similarly to an egg white, it forms threads and can be stretched. This fluidity is ideal for allowing the man’s sperm into the uterus. On non-fertile days, cervical mucus is cloudy and white-coloured. The consistency is tough and therefore more impermeable to sperm.
To be able to better assess their menstrual cycle, women often check the consistency of their cervical mucus, which collects at the vaginal opening. The end of the woman’s fertile days is ascertained by measuring the basal body temperature. This is checked every morning after waking up and before getting out of bed. At the end of the fertile days, the temperature rises by about 0.2 °C and remains at this level until the start of the next cycle. Monitoring physical signs like this is referred to as a symptothermal method. To draw on this method as an indicator of fertile days, women need to monitor their bodies on a daily basis.
Cervical mucus changes its density and colour throughout the course of the menstrual cycle. This means you can find out on which days you have a better chance of getting pregnant. However, you cannot tell whether fertilisation has taken place based on cervical mucus. This can be established only if you miss your next period.
A cervical mucus examination is part of the basic diagnostic process during fertility treatment, in order to check whether your cervical mucus is an optimal transport medium for sperm. To do this, the doctor will take a sample of the mucus on the days around ovulation. This is then examined in the laboratory. The permeability is assessed based on the so-called Insler Score.
Alongside the cervical mucus examination, a compatibility test is usually also performed. To do this, the partner provides a sperm sample. In the laboratory, tests are carried out to determine how well the sperm can move around in the cervical mucus and how high the sperm survival rate is. If this examination reveals that the cervical mucus and sperm cells are incompatible, this may be a reason for difficulties conceiving. In some cases, insemination can then lead to pregnancy. However, other therapy measures can also be taken as part of the fertility treatment.
The embryoscope allows us to keep egg cells/embryos incubated from the moment of fertilisation until the moment they are transferred into the uterus. The incubator maintains a perfectly stable environment by constantly monitoring temperature and pH, as well as the purity of the gas mixture used.
There is no longer any need to remove the embryo from the incubator in order to check progress. This means that the embryo no longer needs to be exposed to fluctuating environmental conditions.
An integrated microscope that is fitted with a special type of camera allows the egg cells/embryos to be constantly monitored throughout the period of incubation.
This allows cell development to be closely monitored, and provides the specialist with more objective selection criteria when it comes to selecting embryos for transfer.
Currently, only 3 centres in Germany offer this high-tech method. We are proud to now offer the Embryoscope method to all our patients.
For further information on the uses of this technology please speak to the physician in charge of your care.
If you choose to undergo artificial insemination, you will probably come across the term follitropin. This is a biotechnologically produced follicle-stimulating hormone which imitates the effect of the body’s own FSH.
Follicle-stimulating hormone is a sex-neutral hormone that is formed in the pituitary glands of both men and women alike. The functions of the hormone are:
Genesis and functionality of testicles and ovaries
Production and maturation of egg and sperm cells
In the female body, FSH plays a major role in the menstrual cycle. In the first half, a particularly high concentration of the hormone is released, which stimulates follicle maturation in the ovaries. The maturing ovarian follicles release oestrogen, which, in turn, inhibits the strong production of FSH. In the end, only one ovarian follicle gets enough of the hormone to mature. This follicle is the one that is used in the next ovulation.
In men, FSH is responsible for sperm cell formation (spermatogenesis).
A physical lack of FSH can have several causes, which include changes in the pituitary gland or genetic information. The exact cause can be determined using blood tests, a CT scan or a simulation test. This deficiency means that little to no FSH is formed and released. In women, this means that ovulation does not occur, or only occurs very infrequently. In men, an FSH deficiency has an effect on sperm quality.
A follitropin administration is used both for men and women in fertility treatments such as IVF or ICSI:
The hormone assists or is a substitute for the natural production of FSH. It allows for better control over the development and maturation of eggs. The strong stimulation of eggs increases the likelihood that multiple eggs will mature and can be retrieved for artificial insemination.
Sperm production can also be increased with the administration of follitropin.
Depending on your treatment plan, either one or both partners will be treated with follitropin during the therapy. The dosage and treatment duration is determined based on examinations. The hormone is administered subcutaneously, i.e. under the skin. This is done via a daily injection in the thigh or the abdominal crease, at the same time every day, whenever possible. Patients often perform the treatment themselves. The growth of gametes is monitored by examinations such as ultrasound or blood samples. If enough egg and sperm cells have matured, the follitropin administration can be stopped.
Treatment with follitropin can also have adverse effects. The most common side effects include rashes at the injection site. Slight swellings or headaches can also occur. At our fertility centres, we will inform you in detail about the possibilities and risks of treatment with recombinant follicle-stimulating hormone.
Intra-cytoplasmic morphologically selected sperm injection, or IMSI, represents a more refined version of the ICSI technology. This method is used to increase the chances of a successful pregnancy in patients who have undergone unsuccessful ICSI attempts.
Both methods involve the selection of sperm prior to fertilisation. However, while in standard ICSI the selection is performed at a magnification of x200, in IMSI it is performed at a magnification of x6500; greater magnification renders certain features more easily visible. Approximately 600 children have so far been born as a result of IMSI treatment.
With immediate effect, we now offer this technology to all our patients. Over the past few months, we have performed a large number of IMSI treatments in our laboratory.
Shortly before the fusion of the maternal and paternal chromosomes (pronucleus stadium/PN) the distribution pattern of the nucleoli (precursor bodies) can be determined through a digitalised, image-generating method. The nucleoli are concentrations of the genetic material in the pronucleus stage. The distribution pattern of these nucleoli allows inferences on the future embryo’s development potential. By selecting the fertilised eggs with optimum distribution pattern, it is possible to choose the cells with the best prognosis.