DOES ASSISTED HATCHING IMPROVE IMPLANTATION RATES AFTER IN-VITRO FERTILIZATION OR INTRACYTOPLASMIC SPERM INJECTION IN ALL PATIENTS - A PROSPECTIVE RANDOMIZED STUDY

Purpose: Preliminary data from some research centers indicate that ass isted hatching might be of value to increase embryo implantation rate in the human, at least in selected cases. It is not clear, however, wh ether this technique would be of benefit for all patients undergoing a n embryo transfer. We therefore performed a prospective randomized stu dy to evaluate the effect of assisted hatching on the implantation rat e in our in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) program. Methods: In total, 120 couples undergoing an embryo t ransfer were randomized between two groups: in one group no assisted h atching was performed (AH-), whereas in the other group the embryos se lected for transfer. were subjected to partial zona dissection (PZD) i mmediately prior to the transfer (AH+). Using a computer-generated min imization procedure, patients were allocated to one of the two groups according to four preselected criteria: the number of embryos transfer red, the cumulative score of transferred embryos, the age of the patie nt, and the use of ICSI. Results: Pregnancy and implantation rates in the AH+ and AH- groups were, respectively, 42.1 versus 38.1% and 17.9 versus 17.1%. Conclusions: From our data we conclude that assisted hat ching through partial zona dissection prior to embryo transfer does no t improve pregnancy and embryo implantation rates in unselected patien ts undergoing IVF or ICSI.