O-066 CSCM-NXC media containing a low lactate concentration seems to benefit expansion grade compared to traditional continuous media

Study question

Does lactate presence in the culture medium have an effect on embryo development, specifically during blastocyst formation? Is it an age related effect?

Summary answer

There is a statistical significative reduction of early blastocyst formation and a trend towards higher proportion of expanded and hatching blastocysts in lower lactate concentration.

What is known already

Embryos after embryonic genome activation start an active consumption of glucose to convert it into pyruvate and lactate for ATP production through the TCA cycle. Conversion from pyruvate to lactate to produce NADH through LDH (lactate dehydrogenase) can be counterbalanced by increased amounts of lactate, which then can alter the NAD+/NADH ratio resulting in a higher oxidative stress and reduced metabolic activity. Recently, a new commercial media formulation with a substantial reduction of lactate has come in to the market reporting increased efficiency of blastocyst formation and amount of euploid embryos compare to its version with a traditional lactate concentration.

Study design, size, duration

From September to November 2021 embryos were cultured in two different continuous media (SAGE 1-STEP and FUJIFILM IRVINE SCIENTIFIC CSCM-NXC). A total of 260 correctly fertilized embryos were allocated in both types of media (119 in 1-STEP and 141 in CSCM-NXC). Patients containing more than one zygote had their embryos allocated as equally as possible in both types of media.

Participants/materials, setting, methods

Age of participants ranged from 24-45 years. The embryos were cultured in embryoscope+ and their destination was assigned as Transfer, Vitrification or Discard (if by day 6 they did not reach a good quality blastocyst). Morphokinetic parameters were measured and Gardner's grading system for blastocyst quality annotated. For blastocyst quality comparison, only day 5 was considered. Variables studied were utilisation and blastocyst formation rates, expansion grade, ICM and TE quality, patient age, and pregnancy rates.

Main results and the role of chance

Incubation of embryos in reduced lactate concentration reduced significantly (p-value=0.013) the proportion of embryos with expansion grade 1 (14.3% 1STEP vs 3.4% CSCM-NXC), in contrast, a trend towards higher expansion grades, more importantly grade 5 (7.8% 1STEP vs 14.9% CSCM-NXC) was observed. A slight reduction in proportion of discarded embryos (47.52% CSCM-NXC vs 54.62% 1STEP) and increased proportion of vitrified embryos (34.75% CSCM-NXC vs 27.73% 1STEP) was also observed. Regarding ICM and TE qualities, in general there was also a trend in benefit of use of CSCM-NXC medium (55.3% CSCM-NXC vs 50.7% 1STEP for grade A in ICM; 36.8% CSCM-NXC vs 30.1% 1STEP for grade A in TE). Morphokinetic parameters were not different between groups, except T3 which showed to be significative (p-value=0.026) earlier in 1STEP than CSCM-NXC (37.13 h vs 38.71 h respectively). Age subgroups of patient showed no difference in utilisation rates for ages < 37 years old, however, for ages ≥37 there was a higher proportion of utilised embryos (56.3 CSCM-NXC vs 41.9% 1STEP for 37-40 years old; 60% CSCM-NXC vs 42.3% 1STEP for >40 years old). Finally, pregnancy rates were equal for those fresh transfers between both groups.

Limitations, reasons for caution

The study has a reduced sample size, so statistical power is reduced. Furthermore, it cannot be discarded that the effect is not a contribution to other differences in formulation of both media. Time to birth or cumulated pregnancy parameter would be more indicative of benefits.

Wider implications of the findings

Two main hypotheses that require further validation: First, excess of certain metabolites in culture can impair development of preimplantation embryos. Second, embryos may be more sensitive to certain medium composition depending on age, so medium designed according to this may be a near future direction to improve IVF outcomes.

Trial registration number

NA

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

What information patients require on graduated compression stockings

Graduated compression stockings are used prophylactically on a variety of patients within acute hospitals. Anecdotal evidence suggests patients have a limited understanding of this treatment. The aim of this qualitative study was to explore patients' experiences of compression stockings and to ascertain perceptions of their use. Information was gathered using telephone interviews from a sample of 12 adults who had been patients within the past 2 months, and who had worn compression stockings for more than 48 hours. The results showed that patients received little or no information from healthcare staff regarding compression stockings, but that they did have knowledge from other sources, such as long-haul flight advice. This raises issues of informed consent and patient empowerment and highlights the need for both verbal and written information. The information gained informed a patient information leaflet, which was developed in partnership with a patient focus group.

Clinical findings among sexually abused children with and without developmental disabilities

Although children with developmental disabilities have a heightened risk for sexual abuse compared to those without disabilities, little is known about effects of sexual abuse on this population. Some researchers suggest that the effects are similar, and victims appear to share the same range of variability as people without disabilities. Others suggest that the effects may be complicated by limited coping resources and disability-related issues. Documented effects of sexual abuse on individuals with developmental disabilities was discussed. Clinical findings among a group of 43 children with and 43 children without developmental disabilities referred for treatment of child sexual abuse were also presented.