Comparing the neonatal outcomes of babies conceived from frozen-thawed and fresh embryo transfers. 
The outcomes of IVF pregnancies conceived from frozen-thawed embryos appear to be healthier, with fewer multiple pregnancies and low-birthweight babies, compared with fresh transfers, study findings suggest.

Presenting author Dr. Anja Pinborg (Copenhagen University Hospital Rigshospitalet, Denmark) told delegates at the 24th annual conference of the European Society of Human Reproduction and Embryology that their findings lay to rest concerns about the effects of freezing and thawing embryos.

The team compared the outcomes of 1,267 children born in Denmark as a result of frozen embryo transfer between 1995 and 2006 with those of 17,857 children conceived from fresh embryos, who served as controls.

Rates of multiple pregnancy were considerably lower among women who underwent IVF or ICSI with cryo-preserved embryos (14.2 and 11.7 percent, respectively) than those who underwent fresh embryo transfer (27.3 and 24.8 percent, respectively), Pinborg et al reveal.

Accordingly, pregnancy duration was significantly longer with frozen-thawed embryos than fresh embryos, birthweight was about 200g higher, and there was no increased risk for congenital malformations.

Fewer children conceived from frozen-thawed embryos were admitted to neonatal intensive care, overall, although this difference disappeared when multiple births were excluded from the analysis, the investigators report. 

“The findings are reassuring, although we still lack sub-analyses regarding malformations and neurological sequelae of the frozen embryo replacement,” Pinborg said.

“If our results continue to be positive, frozen embryo replacement can be accepted as a completely safe procedure, which can be used even more frequently than it is currently.”

ORGYN.com