Single embryo transfer & advanced maternal age: how to succeed?

During this live session, Dr Esther Marbán, Gynaecologist & Fertility Specialist at Clinica Tambre, Madrid, Spain talked about advanced maternal age and explained why single embryo transfer is recommended. Dr Marbán walked through her past patient’s success story from the diagnosis to the pregnancy.

Dr Marban started by defining advanced maternal age, which is considered getting pregnant at 35 years old or older. We know that the egg quality and also the ovarian reserve decrease as age increases, and the chances of carrying a baby with chromosomal disorders such as Down syndrome also increase. When we talk about advanced maternal age, it’s essential to consider the fetal and maternal risks. A higher risk of miscarriage, stillbirth and abnormal growth is related to age, and the maternal risks include high blood pressure, diabetes and premature birth. That’s the reason it’s recommended, if possible, to have a single embryo transfer to avoid those risks that are even higher if we talk about twin pregnancies.

Advanced maternal age & single embryo transfer – real-life case

The case presented by Dr Marban was about a couple in their 40s, the female was 41 years old, she didn’t have any previous IVF attempts, no diseases or current medication at that moment, and her medical family history showed that the patient’s grandmother from her father’s side suffered from breast cancer. Her partner was 42 years old, had no diseases or current medication, and he didn’t have any family history, so we started the diagnosis.

• 41-year-old female with a male partner, low ovarian reserve, no previous IVF attempts, male factor

When we checked the partner’s semen, we found that he had oligozoospermia with a concentration of 8.1 million per millilitre and a total concentration of 28 million, the total motility was 62%, and the morphology was completely normal. He also performed a testicular ultrasound and a Doppler that came back normal, we also tested the karyotype, which was completely normal, with 46 chromosomes 1 X and one Y chromosome according to a normal karyotype in a male. We also did the infectious disease screening, and we also tested the DNA fragmentation, which also came back normal.

We did the DNA fragmentation test to check if there is any kind of DNA damage in the sperm. When we find a high rate of single-stranded DNA fragmentation, it could be related to a lower fertilization rate of the eggs that we will retrieve afterwards. Apart from that, when double-stranded DNA fragmentation is found, we may find a higher chromosomal alteration in the embryos, and it’s also possible to have a lower rate of developing embryos into blastocyst as a result. DNA fragmentation may be related to a lower implantation rate. What can we do in such a case? We always recommend stopping smoking and drinking alcohol, and we recommend reducing our tea, and coffee intake, it’s also recommended to take antioxidants and turmeric, which are quite powerful antioxidants and could help us in reducing DNA fragmentation. We also use a specific technique during fertilization called Chip Fertile, which reduces the chances of selecting a fragmented sperm to fertilize the eggs.

Regarding the female patient, we tested her ovarian reserve, and her AMH was 0.5 ng/ ml, we did a vaginal scan, and her AFC was 3 follicles in each ovary, we also tested the karyotype, which was also normal. Smear test results and the infectious diseases came back normal, as well as the blood cell count and the clotting. The TSH level was 2.3.

Protocols & procedures

The diagnosis in this specific clinical case was a male factor and a low ovarian reserve because of that, we decided and recommended our patients to undergo an IVF treatment with PGT-A, in case we had a good and euploid embryo to transfer just 1 embryo due to her age. We performed ICSI, which is a procedure where a single sperm cell is injected into the cytoplasm of the mature egg, we use a tiny needle called a micropipette, it was necessary to use a microinjector to do that procedure, and we also needed to prepare the eggs and sperm properly.

We retrieved 8 eggs, 5 of them fertilized properly, and we had 2 embryos developing into the blastocyst stage. We did the PGT-A testing, we do the embryo biopsy on day 5 or day 6 of the development of the embryo. The idea is to select chromosomally healthy embryos, and it’s known that it increases the chances of having a healthy baby because it reduces the risk of having a miscarriage, especially in patients older than 40 years old. In such patients, the risk of miscarriage is quite high, and it also increases the probability of pregnancy per transfer, so that’s another good reason to recommend a single embryo transfer in these patients. It also reduces the duration of the treatment on the number of cycles needed because, in the end, we are selecting a good quality embryo, and also a healthy embryo, so the chances of implantation of that embryo are higher. Both embryos were biopsied, 1 of them was a euploid embryo which was transferable and chromosomally healthy, and one was aneuploid.
The euploid embryo contains 23 pairs of chromosomes which is a completely normal embryo, while an aneuploid embryo could have gain or loss of genetic material, and that’s the reason those embryos are not recommended to be transferred. They could end in a miscarriage or in an affected fetus, which we always want to avoid.

Further tests

We also suggested doing EndomeTRIO test to maximize the implantation rate as there was just 1 transferable embryo. This test has to be performed in a mock cycle, we decided to do it with estradiol and subcutaneous progesterone, it could also be performed in a natural cycle, but the mock cycle should be the same as the one that we are using for a real embryo transfer.

We did an endometrial biopsy to check the window of implantation, which is called the ERA test, we also did EMMA test to check the microbiome, and we checked the pathogenic bacteria causing chronic endometriosis, which is called the ALICE test. Both results of EMMA and ALICE were completely normal, so there was no chronic infection in the uterus, but we found that she had a pre-receptive endometrium which means that the window of implantation, which is the moment when the endometrium is more receptive for eventual embryo transfer was not in the normal and correct place in this patient. The test showed that she needed some more hours of progesterone and at least 1 more day of progesterone. It was recommended to do the embryo transfer with 146 hours of progesterone, so with that test, we were able to personalize the embryo transfer, which is what we wanted.

The patient underwent the endometrial preparation for the frozen embryo that we had, she also used estradiol (6 mg every day for 12 days), and we tested endometrium that had a thickness of 8 millimetres, and no-dominant follicles in the ovaries were found. We did luteal phase support with subcutaneous progesterone of 25 milligrams, it was 1 vial every 12 hours for 6 days before the embryo transfer as the ERA test result revealed.

We did a B-hCG test 11 days later, which came out positive, and now the patient is currently 35 weeks pregnant. The non-invasive prenatal DNA test was also performed as a recommendation of our genetic laboratory, even though we knew that the embryo was chromosomally healthy. It’s recommended to do a non-invasive prenatal DNA test to be as sure as possible that the baby is doing fine because, in the end, we are not taking the cells from the embryo, we are just taking the cells from the external part of the embryo, and we know that the relationship between the external cells and the inner mass cells that could be the embryo in the future are quite accurate, but it’s also important to be as sure as possible that the baby is also okay. The test came back normal, and no fetal or maternal complications have been found so far.

Conclusions

• accurate diagnosis and specific tests are essential for a correct assessment and proper treatment
• an important examination of both male and female factors
• IVF and PGT-A help to increase the implantation rate reduces the miscarriage rate and shorten the time to get pregnant, selecting a chromosomally healthy embryo to transfer
• the endometrial assessment also plays a role in personalizing the embryo transfer in these patients
• in advanced maternal age patients, SET (single embryo transfer) is recommended to reduce risks during pregnancy, such as prematurity preeclampsia and diabetes