IVF success rates: factors that influence the outcome

IVF success depends on many factors, including egg quality, sperm quality and genetic characteristics, the number of eggs retrieved, embryo development, the condition of the uterus, the genetics of both partners and the laboratory methods used. For some indications, the selected laboratory methods can also significantly increase the chance of a successful pregnancy. IVF success is therefore individual.

The woman’s age and egg quality

The woman’s age is one of the strongest factors. With age, not only the number of eggs decreases, but especially their chromosomal (genetic) quality. This affects fertilisation, embryo development, implantation and the risk of miscarriage. AMH and the number of follicles help estimate the response to stimulation, but they do not provide complete information about egg quality.

In women of higher reproductive age, it is therefore important not to wait too long, to consider an effective stimulation protocol and to work realistically with the number of cycles and options such as PGT or donor eggs.

Sperm quality and laboratory methods

The semen analysis influences which fertilisation method the embryologist recommends. If sperm count, motility or morphology are impaired, ICSI may be appropriate. In some cases, sperm-selection methods, DNA-fragmentation testing or andrological care are added.

The laboratory phase is crucial in IVF. The experience of the embryologists, culture conditions, timing and correct selection of methods are important. However, additional methods should be indicated where appropriate, rather than automatically offered to everyone.

The embryo and uterine lining

Even a good-quality embryo needs a properly prepared uterine lining. The doctor monitors its thickness, structure and hormonal timing. If the lining is not ready, it may be appropriate to postpone the transfer and freeze the embryo.

Implantation is a biologically complex process. It is influenced by the genetic quality of the embryo, endometrial receptivity, immunological and anatomical factors, lifestyle and overall health.

What the patient can influence

The patient cannot change age or the genetic characteristics of the eggs, but can influence the timing of examinations, adherence to treatment, smoking, alcohol, body weight, sleep, treatment of thyroid disease, diabetes or inflammation, use of recommended medication and, of course, attending the clinic. It is also important to seek care in time.

FAQ

What is the success rate of IVF?

It varies according to age, diagnosis, type of treatment, embryo quality and other factors. An individual prognosis should always be established.

How can the chance of IVF success be increased?

Through timely diagnostics, an appropriate protocol, management of male-factor infertility, correct timing of transfer and a healthy lifestyle.

Is the number of eggs the most important factor?

The number is important, but the quality of the eggs and embryos also matters.

Can genetic testing of embryos help?

For selected couples, it may help when deciding which embryo to transfer, but it is not automatically suitable for everyone.

What if the first IVF cycle fails?

The doctor should evaluate the response to stimulation, embryo quality, the uterine lining and sperm, and propose appropriate next steps, for example additional examinations, modification of the next stimulation or laboratory procedures.