Embryo fragmentation in vitro and its impact on treatment and pregnancy outcome

Objective: To determine the impact of embryo fragmentation on pregnancy, obstetric, and perinatal outcome. Design: Retrospective analysis of embryo transfers that were homogeneous in regard to the degree of fragmentation. Setting: Fertility center. Patient(s): A cohort of 460 fresh embryo transfers. Intervention(s): A total of 164 pregnancies were analyzed for the incidence of antepartum complications during gestation, obstetric (multiple pregnancy, preterm delivery, cesarean section), and perinatal outcome (sex, birth weight, admission to neonatal intensive care unit, malformations). Main Outcome Measure(s): Implantation and clinical pregnancy rate, obstetric and perinatal outcome. Result(s): Embryo fragmentation and number of embryos per transfer showed a significant influence on clinical pregnancy and implantation rate. No such relation was found concerning complications, multiple pregnancy rate, incidence of cesarean section, gestation week, birth weight, and average time at the neonatology. On the other hand, pregnancies derived from bad-quality embryos had a significantly higher rate of malformations. Conclusion(s): The higher percentage of malformations found in bad-quality embryos may be due to a higher percentage of apoptotic features and chromosomal disorders. For ethical reasons, the transfer of embryos with > 50% fragmentation should be considered only after consultation with the patient. (C) 2001 by American Society for Reproductive Medicine.