PREGNANCY OUTCOME AFTER REPLACEMENT OF FR OZEN-THAWED EMBRYOS AND AFTER TRANSFER OF FRESH EMBRYOS IN FRENCH IVF REGISTRY

The french in vitro fertilization registry FIVNAT allowed us to descri be the most important cohort of pregnancies resulting from the replace ment of frozen-thawed embryos, and to compare them with pregnancies is sued from fresh embryos transfers. From 1987 to 1992, 465 and 8 757 cl inical pregnancies were respectively collected, and resulted in the bi rth of 386 et 8729 babies. Whereas the miscarriage rate was higher, pr egnancy evolution was more normal after transfer of frozen-thawed embr yos. Multiple pregnancies were less frequent , preterm birth rates and low birth rate were also significantly lower Nevertheless, after cryo preservation of embryos, more complications were noted. However, furth er analysis involving more pregnancies after transfer of frozen-thawed embryos is necessary before reaching conclusion. Finally, congenital malformation rate was not different between the two groups.