Failed IVF: What Could Be the Cause of an Unsuccessful Cycle?

Unfortunately, IVF treatment does not always end in success. In the case of young women, there is a higher probability of becoming pregnant through this method, with a pregnancy rate of 60% among those under the age of 35.

Causes of failure in IVF cycles

Repeated failures in IVF or in vitro fertilization cycles can be due to many reasons. Our fertility specialists explain the causes behind implantation failures.

1. Maternal age: Spain is the second country in the European Union with the highest percentage of first-time mothers aged 40 or older at the time of childbirth—7.4% of the total, only surpassed by Italy with 8%. This delay in motherhood is possibly the most frequent cause of failure in assisted reproduction treatments.
   
   Among women aged 40 or older undergoing IVF treatment, only 20–25% achieve success. Of those who do not succeed after three IVF attempts, 68% turn to egg donation.
    
2. Embryo quality: The success of an IVF treatment depends 70–80% on the quality of the embryo obtained after fertilizing the woman’s eggs with sperm from her partner or from a sperm bank in the case of women without a male partner.
   
   The remaining 20–30% of failure cases could be related to different factors such as thrombophilias, immunological disorders, intrauterine infections, or uterine pathologies like fibroids or polyps—in short, anything that may interfere with embryo implantation.
    
3. Ovarian reserve: From the age of 35, the ovarian reserve—which can be determined by counting antral follicles in a transvaginal ultrasound or by measuring Anti-Müllerian Hormone (AMH) levels in the blood—decreases, as does the quality of the eggs and, consequently, of the embryos derived from them.
   
   When embryos are taken to extended culture in the lab—until day 5 or 6, the stage known as blastocyst—we are trying to select the embryos with the best morphological characteristics and, in theory, the highest implantation potential. But in practice, we see that many of these embryos, if biopsied for preimplantation genetic testing, would be aneuploid, meaning chromosomally abnormal.

In the group of women aged 38–40, out of 10 blastocysts analyzed in the genetics lab, only about 3 would be euploid (normal), and in this same age group, to obtain one euploid blastocyst, around 14 mature oocytes would be needed.

In summary, the higher the age, the fewer oocytes and the worse the embryo quality. If the embryos are not tested, chromosomally abnormal embryos could be transferred to the uterus, potentially causing implantation failure, biochemical pregnancies, or early miscarriages.

What to do after a failed IVF cycle?

Receiving news of a negative IVF result is always a very painful and delicate situation for the patient and/or her partner. Emotionally, it may take more or less time to recover. In some cases, psychological support may be needed.

After a failed IVF cycle, it is recommended to carry out a personalized study to determine the cause of the failure and optimize the next cycle to achieve pregnancy.

After a negative IVF result, if the reproductive system has not yet recovered (generally the cause is ovarian or hormonal), the following can be done:

• Wait for the next cycle or period and evaluate.
• Begin a contraceptive treatment that helps “block” reproductive function. This treatment is usually prescribed for about two weeks, after which a control evaluation is performed. If the reproductive system has reached a resting state, the contraceptive is stopped to allow a new period and initiate treatment.

If the reproductive system has recovered, the next step in the treatment process can be taken. Depending on the individual, the following cases may occur:

Cases

• IVF where embryos were obtained but no embryo transfer was performed—for example, due to a risk of hyperstimulation, an elective decision to vitrify, or preimplantation genetic testing (PGT).
• IVF with a fresh embryo transfer, but there are still vitrified embryos available for further attempts.

Solution

In these two cases, the patient should begin ideal endometrial preparation for a new embryo transfer (in a natural or substituted cycle with estrogens and progesterone), which takes place approximately 15–20 days later.

Case

• IVF where no suitable embryos were obtained for transfer, either fresh or vitrified.

Solution

If no embryos were obtained, another ovarian stimulation cycle may be started to retrieve new oocytes, or egg donation may be considered, depending on the individual patient’s situation and the response in previous ovarian stimulation.

If several embryo transfers have been carried out without success—typically more than three, known as implantation failure—or if recurrent miscarriages have occurred (more than two), it is necessary to conduct additional tests such as hysteroscopy, hematological studies, or immunological tests, among others.

These studies aim to investigate in greater depth the causes preventing the achievement or development of a pregnancy.

Do you have any questions or need more information?

At Fertility Madrid, we specialise in treatments such as egg donation, in vitro fertilisation and artificial insemination, among others.

Please do not hesitate to contact our professionals at our fertility clinic and they will answer all your questions without obligation.