During the last decade, improvement of cryopreservation of unfertilized egg cells has been achieved. This has largely been based upon results from several catholic countries where cryopreservation of fertilized eggs is forbidden. The results of these procedures in young women are now comparable to the results from using fresh eggs cells, why we now also offer this treatment.
The egg cells are frozen with the same procedure we use to freeze blastocysts – vitrification - and is kept frozen at - 196°C. The patients that we primarily think will go for cryopreservation of egg cells are:
Cryo – thaw cycle:
If regular menstrual cycle is present we normally choose to transfer thawed embryos in natural cycle. To coordinate the timing of the lining of the womb, we stimulate the ovulation when the follicle is large enough and when the endometrium possesses adequate cycle quality.
The thawed oocytes is coordinated with the endometrium in relation to ovulation induction injection of hCG. After thawing the oocyte – ICSI is done a couple of hours later. The developing embryos are transferred at day 2, 3 or at blastocyst stage day 5 or 6. .
Improved results:
| Cryo/thaw 2006-2008 | ||
|---|---|---|
| EMBRYOS | ||
| No. thawed | 2633 | |
| No. survived | 1992 | 76% |
| No. transfers | 1431 | 54% |
| No. of growing embryos | 1442 | 55% |
Pos test is judged from serum analysis. Clinical pregnancy rate represent patients with proven fetal heart rate by ultrasonography.
| Cryo/thaw result related to transfers 2006-2008 | |||
|---|---|---|---|
| Embryos transferered | No. | pos. hCG | %pos. hCG |
1 embryo transfered |
264 | 43 | 23,4 |
| 2 embryos transferered | 808 | 202 | 35,1 |
| 3 embryos transferered | 207 | 53 | 37,7 |
| Related to age (years) | |||
| <30 ( 2006+2007) | 54 | 24 | 44,4 |
| 30-35 | 142 | 56 | 39,4 |
| 35-40 | 177 | 55 | 31,1 |
| >40 | 151 | 39 | 25,8 |
| Total transferred/pregnant | 905 | 275 | 30% pregnant |
474 have delivered after cryo/thaw treatment during 1993-2008, of those 250 from 2006 to 2008.