We hear more and more about so-called add-ons: additional tests, techniques or treatments that can be added onto an IVF, egg donation, embryo transfer treatment or fertility assessments.
The term has become increasingly popular in recent years because many patients come to their appointments after reading about techniques that claim to improve implantation, better select embryos or increase the chances of pregnancy.
And it's understandable: when pregnancy doesn't happen a expected, any option that might help naturally inspires hope. However, in assisted reproduction, it''s important to keep one key idea in mind: more tests or more interventions does not necessarily mean a higher chance of pregnancy.
The key is understanding what each individual case actually requires, when an additional technique may provide real value, and when there is no clear medical indication for using it.
What are the add-ons in assisted reproduction?
Add-ons are additional interventions incorporated into a fertility treatment with the aim of improving a specific aspect of the reproductive process. They can be used at different stages of treatment:
- Before treatment, through additional diagnostic tests.
- During ovarian stimulation or endometrial preparation.
- In the laboratory, during fertilization or embryo culture.
- At the time of the embryo transfer.
- After embryo transfer, as supportive treatment.
Some common examples include time-lapse embryo monitoring systems, advanced sperm selection techniques, specialized embryo transfer media, endometrial studies, immunological testing, thrombophilia screening, endometrial PRP, microbiome testing, PGD testing and assisted hatching.
Some of these techniques can be beneficial in carefully selected cases. The problem arises when they are presented as universal solutions or as essential steps for every patient, regardless of their individual circumstances.
Why do add-ons cause so much confusion?
Reproductive medicine is advancing rapidly. Every year, new technologies, new studies and new ways of assessing eggs, sperm, embryos and the endometrium emerge. This is a positive development because it allows treatments to be tailored more precisely to each patient. However, it can also create confusion. A technique may appear promising in early studies yet still lack clear evidence that it improves ongoing pregnancy or live birth rates across the broader patient population.
It is also possible for a test or procedure to be beneficial for a specific group of patients while offering little or no advantage when used routinely for everyone.
For this reason, before incorporating any additional technique into a treatment plan, it is important to consider three key questions:
- What problem is it intended to solve?
- What evidence supports its use for this particular patient profile?
- Will the results meaningfully influence the treatment strategy?
Add-ons are not a guarantee
One of the most common misconceptions is that an add-on will automatically increase the chances of pregnancy. This is not necessarily the case.
Assisted reproduction is influenced by many different factors, including the patient's age, ovarian reserve, egg quality, male factor infertility, embryo quality, endometrial health, reproductive history, genetics and response to previous treatments.
An add-on may help by providing additional information, optimizing a specific part of the process, or allowing the treatment strategy to be tailored more precisely. However, it is rarely capable of changing the overall reproductive prognosis on its own.
For this reason, it is important to be cautious of any claims that promise guaranteed results. Advanced reproductive medicine is not about using every available technique but about carefully selecting the interventions that are most likely to provide meaningful benefit for each individual patient.
When does an add-on make sense?
An add-on may be justified when it addresses a specific clinical question. For example:
- Is there a history of recurrent pregnancy loss?
- Have there been previous implantation failures?
- Is there suspicion of an underlying endometrial abnormality?
- Does the semen analysis show significant abnormalities?
- Have embryos shown poor development in previous treatment cycles?
- Should the embryos be genetically tested because of maternal age or a known genetic risk?
- Is the endometrium failing to reach optimal conditions before embryo transfer?
- Could an additional test meaningfully change the treatment plan?
When there is a clear medical indication, these techniques can be a valuable part of a well-reasoned medical strategy. When they are used "just in case", however, their potential benefit is often far less certain.
Examples of add-on techniques in assisted reproduction
Time-lapse systems for embryo culture
Time-lapse incubators allow embryos to be monitored throughout their development without removing them from their controlled culture environment. This reduces unnecessary handling and provides the embryology team with continuous information about their progression.
This technology can help with a more detailed assessment of embryo development and support the selection of embryos with greater potential. However, it should always be understood as a supportive too within the broader work of the embryology laboratory.
Advanced sperm selection
In some treatments, particularly when a male factor is involved, it may be useful to employ more specific sperm selection techniques.
Their aim is to select sperm with more favorable characteristics for fertilization. The decision to use these techniques depends on factors such as semen analysis results, total motile sperm count (REM), sperm DNA fragmentation, previous treatment outcomes or embryo development observed in the laboratory.
Not all patients require the same sperm selection techniques. This is why an individualized approach is essential.
Embryo transfer media
Specific culture media have been developed to support the interaction between the embryo and the endometrium during embryo transfer. They may be of interest in certain cases, particularly when the medical team believes they could provide value at that specific stage of treatment.
However, they do not replace good embryo quality, proper endometrial preparation, or a well-performed embryo transfer procedure.
Endometrial microbiome testing
The endometrium has its own microbiological environment. Endometrial microbiome testing analyzes the composition of microorganisms present in the endometrium and can help determine whether there is an imbalance that may affect the environment in which embryo implantation takes place.
It may be useful when there is clinical suspicion, previous treatment failures, or relevant medical history. However, it does not necessarily need to be a routine test for all patients before embryo transfer.
Endometrial PRP
PRP, or platelet-rich plasma, is obtained from a sample of the patient's own blood. In assisted reproduction, its use has been studied in cases of thin endometrium, difficulty achieving an adequate endometrial thickness or previous implantation failures.
It may be an option for certain patient profiles, but it should be recommended after considering the complete clinical history. It is more appropriate when there is a specific endometrial issue to address rather than being used as a general "boost" for every embryo transfer.
Immunological studies, KIR/HLA-C testing and thrombophilia screening
In some cases, particularly in situations involving recurrent pregnancy loss, implantation failures or specific medical history, it may be appropriate to expand the evaluation with immunological tests, KIR/HLA-C testing or thrombophilia screening.
The key is to avoid turning these tests into indiscriminate screening procedures. They should be requested when the clinical history supports their use and when the results have the potential to meaningfully change the treatment strategy.
The key question: "What does my case need?"
When a patient is undergoing assisted reproduction treatment, it is completely natural to want to do everything possible. However, doing everything is not always the most effective approach.
Sometimes, adding tests or techniques without a clear indication can lead to additional costs, more uncertainty, longer waiting periods or increased anxiety without providing a proven benefit for that specific case.
An add-on is appropriately considered when it has a clearly defined purpose and forms part of a broader treatment strategy. It should not be presented as a standalone promise or as a guarantee of pregnancy.