01/ How many embryos are needed for a sucessfull cryopreservation?

The viability of cryopreserved embryos is determined by a combination of biological and technical factors. Regardless of the technicians’ experience level and technical skill, some attrition in the recovery of viable embryos at thaw and the number of embryos that will result in live-born offspring upon transfer should be expected.

One should estimate that 20-25% of frozen-thawed embryos will produce live offspring; therefore, we recommend preserving sufficient embryos to re-establish a given line a few times before an additional cohort of embryos would need to be cryopreserved. In general, this is between 100-300 embryos per rodent model. Zeeva has preserved 250-300 embryos per rodent model.

02/ What are the risks of this embryo Cryopreservation procedure?

Embryo freezing poses no risk to resulting pregnancies. Researchers have shown that fewer frozen-thawed embryos are associated with lower preterm birth rates, low birth weight, growth restriction, and perinatal mortality. The main risks associated with embryo cryopreservation are Damage to embryos during the freezing process. Embryos that are not viable for freezing. Failure to get pregnant after embryos are thawed and implanted. Increased rates of medical issues in pregnancy like preeclampsia and placenta accrete spectrum. Multiple births if more than one embryo is implanted

03/ What if one of us changes our mind about using or donating embryos?

Before using an embryo in treatment or research, you, your partner, or the donor(s) (if applicable) can withdraw consent at any time before the embryos are used. If consent is withdrawn before one year of storage, stored embryos will be removed from storage and allowed to perish. If consent is withdrawn after one year, embryos that were intended for use in treatment cannot be used.

04/ What is the success rate of a good embryo transfer?

The embryo can be transferred at day 3 or blastocyst stages (Day 5 or Day 6). According to the age and quality of the embryos, the success rate ranges from 80% to 30%.

05/ Is it safe to use frozen embryos in treatment?

A major risk is having multiple children (twins or triplets), which pose serious health risks to both mother and child. When you transfer only one embryo to the womb, this process is known as elective single embryo transfer, which reduces the likelihood of having multiple births. Treatment with frozen embryos is just as safe as using fresh embryos.