Elective single embryo transfer: the value of cryopreservation.
In-vitro fertilization is associated with a high rate of multiple pregnancies, a consequence of the number of embryos transferred. There is a challenge in avoiding even twin pregnancies in assisted reproduction, and this can be accomplished with elective single embryo transfer and a good cryopreservation programme. In our follow-up study, we analysed all our elective single embryo transfers during 1998-1999. In all these cycles at least one embryo was frozen. A total of 127 elective single embryo transfers were performed with a clinical pregnancy rate of 38.6%. The highest implantation rate was obtained with four-cell embryos with <10% fragmentation (39.8%). Thirty-four patients have delivered (26.8%), one of these being a monozygotic pregnancy. In total 129 frozen-thawed cycles have been achieved in 83 patients. One frozen-thawed embryo has been transferred in 46 cycles with a clinical pregnancy rate of 17.4%, and two embryos have been transferred in 83 cycles, with a clinical pregnancy rate of 37.3%. Up until now, 66 of 125 patients in our single embryo transfer programme have delivered or have on-going pregnancies, and 77 still have embryos frozen. The cumulative delivery rate per oocyte retrieval is 52.8% and the twin rate 7.6%. We conclude that elective single embryo transfer with a good cryopreservation programme results in very acceptable pregnancy rates with a low risk of twins. This is a cost-effective practice that substantially reduces all risks associated with multiple pregnancies and lowers the cost per delivery.
Tiitinen
A
A
Department of Obstetrics and Gynaecology, Helsinki University Central Hospital, PO Box 140, 00029 HUS, Finland. aila.tiitinen@hus.fi
Halttunen
M
M
Härkki
P
P
Vuoristo
P
P
Hyden-Granskog
C
C
D003362:Cost-Benefit Analysis; D015925:Cryopreservation; D010064:Embryo Implantation; D004624:Embryo Transfer / Q000191:economics / Q000379:methods*; D004622:Embryo, Mammalian / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D011247:Pregnancy; D011256:Pregnancy Outcome; D011272:Pregnancy, Multiple; D012307:Risk Factors; D020554:Sperm Injections, Intracytoplasmic