O-261 In-vitro supplementation of vitamin B12 to improve post-thaw viability and DNA integrity

Study question

Does the supplementation of vitamin B12 protect the spermatozoa against damage caused by the freeze-thaw process further improving the overall post-thaw survival and DNA integrity?

Summary answer

The antioxidant property of vitamin B12 protects the spermatozoa and improves the post thaw motility, vitality, and reduces DNA damage caused by freeze-thaw process.

What is known already

Cryopreservation of spermatozoa is an effective way of fertility preservation in humans, often used in Assisted Reproductive Technology(ART). Despite the refinement in cryopreservation, the salvage of post-thaw sperms remains poor. The reactive oxygen species(ROS), that is formed as a result of freeze-thaw process is known to decrease the motility, plasma membrane integrity and increase the DNA fragmentation. Most vitamins have antioxidant properties, that protect the mammalian cells from oxidative stress one such vitamin is cyanocobalamin(vitamin B12). Vitamin B12 modulates oxidative stress through methionine synthase activity and also acts as a scavenger of ROS. Thus protecting the DNA against free radicals.

Study design, size, duration

This prospective observational study was performed for a period of 6 months in 111 men, who attended the fertility clinic. The study population included all semen samples except men with azoospermia, surgically retrieved samples and men on vitamin supplements. The study population contained men ageing between 21-40 years.

Participants/materials, setting, methods

Semen samples were analysed according to WHO 5th edition and were assessed for DNA fragmentation index (DFI) using sperm chromatin dispersion assay (SCD). The ejaculates were split into two as group A: semen samples with equal amount of cryoprotectant and group B: semen samples with equal amount of cryoprotectant supplemented with Vitamin B12 (2mg/ml). They were frozen for a minimum of 24 hrs. Post-thaw motility, vitality and DFI were assessed and compared.

Main results and the role of chance

The mean age of patients in our study was 34.26±4.7yrs. 58.5% of the study population had primary infertility. 37.8% of the study population had male factor infertility, 32.4% had oligoasthenoteratozoospermia(OAT), 31.1% had normozoospermia 16.2% had asthenoteratozoospermia, 13.5% had teratozoospermia, 3.6% had oligozoospermia and rest 2.7% had asthenozoospermia.

There was an overall increase in post thaw motility (41.59±18.09 vs 32.3±18.8,p=0.0005), progressive motility (21.54±13.02 vs 15.91±11.80,p=0.0005), vitality (57.14±15.09 vs 46.76±16.45,p=0.0005) and a significant decrease in DFI (26.69±10.03 vs 32.09±10.00,p=0.0005) in group B compared to group A.

Our study also demonstrated that, Normozoospermia patients had a significant increase in vitality (67.17±13.8 vs 58.51±12.0, p = 0.007) and lower DFI (22.68±9.3 vs 27.6±8.9, p = 0.02) in group B than in group A.

OAT patients had a significant increase in total motility (26.25±12.15 vs 15.7±11.4,p=0.0003), progressive motility (11.69±8.8 vs 6.14±5.8,p=0.0028), vitality (46.06±11.34 vs 34.31±12.99,p=0.0001) and significantly lower DFI (30.22±9.87 vs 36.08±9.7,p=0.012) in group B.

Teratozoospermia patients showed significant increase in progressive motility in group B (27.87±8.81 vs 19.33±10.69,p=0.02) and

Asthenoteratozoospermia patients showed significant increase in total motility (40.72± 13.14 vs 30.89±13.06,p=0.02) and vitality (54.39±12.28 vs 43.78±14.14,p=0.02) in group B.

However, in asthenozoospermic patients the parameters were comparable in both the groups.

Limitations, reasons for caution

Due to ethical reasons the samples were not used for in vitro procedures such as intrauterine insemination(IUI), in vitro fertilization (IVF) and intracytoplasmic sperm injection(ICSI). Hence, no inference was obtained regarding the fertilization rates/ pregnancy rates.

Wider implications of the findings

Our study demonstrated that with supplementation of vitamin B12 the recovery rate significantly increased and also preserved the DNA content. Among the various categories, supplementation of vitamin B12 to OAT samples was more beneficial as it improved the overall viability of the sperms.

Trial registration number

CSP/21/JUL/96/389

P–301 Intrauterine instillation of autologous platelet rich plasma for thin endometrium improves the outcome of frozen embryo transfer cycles

Study question

How does the intrauterine instillation of autologous platelet rich plasma (PRP) affect the endometrial thickness and live birth rate in frozen embryo transfer cycles?

Summary answer

Intrauterine instillation of autologous PRP resulted in significant improvement in endometrial thickness. The live birth rates were satisfactory post-PRP instillation.

What is known already

Autologous Platelet rich plasma (PRP) had resulted in significant improvement in endometrial thickness, when instilled intrauterine in women with thin endometrium in FET cycles.

Study design, size, duration

A retrospective observational study was performed at a tertiary care university teaching hospital in South India. 35 women who received intrauterine autologous PRP during endometrial preparation for frozen embryo transfer from June 2017 to December 2020, were included. Patients who underwent donor oocyte recipent cycles, those with a history of tubercular endometritis, Asherman syndrome, previous intrauterine manipulations such as manual removal of placenta, and uterine anomalies were excluded.

Participants/materials, setting, methods

All the women underwent endometrial preparation in artificial cycles by depot GnRH agonist suppression and HRT (Hormone replacement therapy) was initiated by 4–6 mg of estradiol valerate and stepped up as required. Autologous PRP was offered to all women who had endometrial thickness < 7 mm on day 16 of HRT. PRP was prepared by the two-step centrifugation method and administered intrauterine by IUI catheter. The patients underwent repeat evaluation after 5 days post-PRP instillation.

Main results and the role of chance

Optimal response to PRP was considered as the attainment of an endometrial thickness (ET) ≥ 7mm after 5 days of post-PRP. 25 (71.4%) had an optimal response to PRP. There was a significant improvement in the endometrial thickness(mm) in the study participants following PRP instillation: 6.3 ± 0.6 vs. 7.1 ± 1.2; P = 0.0001.The study participants were divided into two groups based on their response to intrauterine PRP instillation. Those who optimally responded to PRP were categorized as Group A and those who didn’t were categorized as Group B. The study participants of both the groups were comparable by their demographic characteristics such as age, cause of infertility, indications for ART, and the dose of estradiol valerate before PRP. The dose of estradiol valerate (mg) after PRP was significantly higher in Group B compared to Group A: 19.9 ± 4.9 vs. 15.6 ± 3.9; P = 0.014. A total of 26 women underwent embryo transfer and 9 (25.7%) women had cycle cancellation. Of these 22 were from Group A and 4 from Group B. The pregnancy, clinical pregnancy, miscarriage and live birth rates were 36.3%(8/22) and 25% (1/4); 31.8% (7/22) and 25% (1/4); and 31.8% (7/22) and 25% (1/4), respectively.

Limitations, reasons for caution

As the study was retrospective in nature and the PRP was offered only in patients who had consented, there was a significant bias. Hence the results of the study should be interpreted with caution. Further large prospective RCTs (Randomised controlled trials) are required to confirm our findings.

Wider implications of the findings: Autologous PRP may enhance the response to the estrogen preparations. It may produce satisfactory live birth rates and reduce cycle cancellations in a reasonable proportion of patients with thin endometrium in FET cycles. However, these findings should be confirmed by dose finding clinical trials, and studies involving a comparison group.

Trial registration number

Not applicable