P-539 Effects of gender of chromosomal translocation's carrier on pre-implantation genetic testing for structural rearrangement (PGT-SR) outcomes

Study question

Do the outcomes of PGT-SR cycles vary according to the gender of chromosomal translocation’s carrier?

Summary answer

The rate of balanced embryos was significantly higher when translocation carrier was a male as compared to female, but clinical outcomes were not significantly different.

What is known already

It has been well described that chromosomal translocations lead to very high rate of unbalanced embryos, and have a subsequent negative impact on blastulation, implantation, miscarriage and live birth rates.PGT-SR allows selecting balanced embryos and increases the chances of pregnancy, while decreasing the risk of micarriage in couples with chromosomal translocations. However, whether the gender of translocation carrier is associated with significantly different impact on PGT-SR outcomes is not known.

Study design, size, duration

This is a monocentric retrospective cross-sectional study conducted in all PGT-SR cycles performed between 2015 and 2020.

A total of 603 cycles, carried out in 283 couples, were included in the analysis.

Participants/materials, setting, methods

Two groups have been formed according to the gender of translocation carrier, Group 1 for female carriers (107 couples, 229 cycles), and group 2 for male (175 couples, 373 cycles).

The rate of balanced embryos, ovarian stimulation parameters, number of oocytes, biopsy rate, clinical pregnancy rate and live birth rate were compared between both groups.

Main results and the role of chance

Female age and infertility etiologies were comparable between both groups.

Mean total dose of gonadotrophin and peak E2 levels were not significantly different in both groups (2422± 895 units vs 2290 ± 858 respectively, p > 0.05) (2460± 1346 pg/ml vs 2497 ± 1397, p > 0.05). There was no significant difference in the number of oocytes and biopsied embryos rate between Group 1 and Group 2.

The rate of balanced embryo after PGT-SR was significantly lower in group 1 (female carriers) than in group 2 (21.1% vs 24.8% respectively, p = 0.036). Finally, biochemical pregnancy rate and live birth rate per transfer were not statistically different between both groups (46.2% vs 43.2% and 20.3% vs 18.5% respectively, p > 0.05).

Limitations, reasons for caution

The retrospective nature of the study was its main limitation. PGT-A was not used, preventing from concluding on embryo euploidy rate.

Wider implications of the findings

Further fundamental studies should be performed to explore the respective mechanisms involved in chromosomal rearrangements according to gender. Our study suggests that a higher number of oocytes could be targeted in female translocation carriers in order to increase the probability of obtaining at least one balanced embryo.

Trial registration number

2

P–665 Influence of premature progesterone elevation on embryo development

Study question

Does a serum progesterone level higher than 1.3 ng/mL on the day of ovulation trigger have an impact on blastocyst development?

Summary answer

Elevated progesterone level has no significant impact on top blastocyst rate, usable blastocyst rate and on morphokinetics.

What is known already

Premature elevation of progesterone level on the day of ovulation trigger prior to IVF is common and causes a decrease in endometrial receptivity. A freeze all strategy is then recommended. However, cumulative live birth rates have also been described as lower in cases of high progesterone levels.

Study design, size, duration

This was a retrospective bicentric cohort follow-up study, including 1150 IVF/ICSI cycles performed between 2016 and 2018 with at least 1 day–5 blastocyst available for transfer or freezing. Among these cycles, 524 were performed with use of a time-lapse system (Embryoscope). Serum Progesterone level was measured on the day of ovulation trigger, and a value >1.3 ng/ml was used to identify premature progesterone elevation.

Participants/materials, setting, methods

The cycles were divided into 2 groups according to serum progesterone level: 1335 cycles were allocated in the normal progesterone group (P < 1,3) and 215 in the progesterone premature elevation group (P > 1.3). Patient’s characteristics, ovarian stimulation characteristics, IVF cycles characteristics and embryology parameters were anonymously recorded and compared between the 2 groups.

Main results and the role of chance

Female age, smoking status, AFC and AMH levels were comparable between the 2 groups. Female BMI was significantly higher in the P < 1,3 than in the P > 1.3 group (26.1 versus 24.7 kg/m² respectively). Total FSH dose, estradiol level, number of follicles >11mm and number of retrieved oocytes were significantly higher in the P > 1.3 group than in P < 1.3 group No difference was observed between the 2 groups in terms of top blastocyst rate per mature oocyte and usable blastocyst rate per mature oocyte. When morphokinetic analysis was available, time to blastulation was the only significantly different parameter between the 2 groups (110.4 hours in P < 1.3 versus 107.9 hours in P > 1.3, p = 0.04). Cumulative live birth rate per cycle was not statistically different between the two groups (23.1% for P < 1.3 versus 28.7% for P > 1.3) (p > 0.05).

Limitations, reasons for caution

The retrospective design of the study should lead to careful analysis of the results. The progesterone threshold refers to a specific assay, and should not be generalized to other assays.

Wider implications of the findings: Premature elevation of serum progesterone level on the day of ovulation trigger does not seem to affect embryo developmental competence. This further supports the relevance of freeze all strategy in this situation.

Trial registration number

Not applicable

Evolution of serum Anti-Müllerian Hormone (AMH) level in young women treated with chemotherapy for breast cancer according to basal AMH level

OBJECTIVE

Serum AMH level has been shown to decrease in women treated for breast cancer in several studies. However, whether basal AMH status affects AMH dynamics during chemotherapy remains to be clarified. The objective of this study was to compare serum AMH dynamics in young women with either low, normal or high basal serum AMH level at diagnosis, during and after treatment with chemotherapy for breast cancer.

STUDY DESIGN

In this secondary analysis of a prospective cohort study, serum AMH was measured during and after chemotherapy in 239 women of reproductive age diagnosed with breast cancer and treated with chemotherapy. The association between AMH dynamics throughout chemotherapy and during follow-up and basal AMH status, i.e. low AMH (<1 μg/l, <7 pmol/l), normal AMH (1-4.9 μg/l, 7-36 pmol/l) and high AMH (≥5 μg/l, >36 pmol/l), was evaluated. Menses occurrence was also recorded.

RESULTS

A total of 21 women had low, 154 had normal and 64 had high basal AMH level. Serum AMH rapidly decreased during chemotherapy in all groups, and its variation during chemotherapy and follow-up was not significantly different between the 3 groups.

CONCLUSION

No association was found between AMH variation during chemotherapy and follow-up, and basal AMH level at diagnosis. However, women with high basal AMH levels have significantly higher AMH levels throughout chemotherapy and follow-up than women with normal or low basal AMH levels at diagnosis.

Decrease of blood anti-α1,3 Galactose Abs levels in multiple sclerosis (MS) and clinically isolated syndrome (CIS) patients

The etiology of multiple sclerosis (MS) remains elusive. Among the possible causes, the increase of anti-Neu5Gc antibodies during EBV primo-infection of Infectious mononucleosis (IMN) may damage the integrity of the blood-brain barrier facilitating the transfer of EBV-infected B cells and anti-EBV T cell clones in the brain. We investigated the change in titers of anti-Neu5Gc and anti-α1,3 Galactose antibodies in 49 IMN, in 76 MS, and 73 clinically isolated syndrome (CIS) patients, as well as age/gender-matched healthy individuals. Anti-Gal and anti-Neu5Gc are significantly increased during IMN (p=0.02 and p<1.10^-4 respectively), but not in acute CMV primo-infection. We show that, whereas there was no change in anti-Neu5Gc in MS/CIS, the two populations exhibit a significant decrease in anti-Gal (combined p=2.7.10^-3), in contrast with patients with non-MS/CIS central nervous system pathologies. Since anti-Gal result from an immunization against α1,3 Gal, lacking in humans but produced in the gut, our data suggest that CIS and MS patients have an altered microbiota or an altered response to this microbiotic epitope.

WBP2NL/PAWP mRNA and protein expression in sperm cells are not related to semen parameters, fertilization rate, or reproductive outcome

PURPOSE

WBP2NL/PAWP, a protein found in the post-acrosomal region of mammalian spermatozoa, has been proposed as a sperm-borne oocyte-activating factor (SOAF) contributing to Ca²⁺ release within the oocyte and subsequent fertilization and embryo development. However, its relevance as either a diagnostic or a prognostic marker of fertilization failure has been questioned in the recent literature. We analyzed WBP2NL/PAWP gene and protein expression level and localization in patients without previous intracytoplasmic sperm injection (ICSI) cycles in order to assess its association with both sperm characteristics and ability to fertilize.

METHODS

Raw frozen-thawed semen samples from 33 couples referred for oocyte donation were included in the study during 2015. Relative protein expression versus α-tubulin (western blot, WB), proportion of post-acrosomal WBP2NL/PAWP-positive spermatozoa over the total number of sperm cells (immunofluorescence), and WBP2NL/PAWP gene expression (RT-qPCR) were analyzed and correlated with semen analysis parameters (number, motility, and morphology) and with reproductive outcomes.

RESULTS

WBP2NL/PAWP protein was expressed in all samples with high variability: relative protein expression (1.77 ± 0.8, range [0.4-3.7]), proportion of positive cells (49.6% ± 16.1, range [22-89]), and relative gene expression (7.3 ± 8.2). No significant correlation (R ² < 0.1) was found between gene and protein expression, neither between WBP2NL/PAWP gene or protein expression, and fertilization rate or other reproductive outcomes (i.e., pregnancy). In contrast, we found significant correlation between sperm morphology and WBP2NL/PAWP semiquantitative analysis in WB (r = -0.42, p < 0.05) and for sperm motility and WBP2NL/PAWP expression in IF (r = 0.52, p < 0.05).

CONCLUSION

Taken into account that WBP2NL/PAWP gene and protein levels and distribution did not correlate with fertilization rates, this study questions the interest of WBP2NL/PAWP protein and gene expression analysis in sperm cells as a prognostic factor for the outcome of ICSI cycles. Larger studies focusing on WBP2NL/PAWP protein and gene expression are needed in order to evaluate the role of WBP2NL/PAWP as a prognostic factor for ART.