A high oocyte yield for intracytoplasmic sperm injection treatment is associated with an increased chromosome error rate.

OBJECTIVE

To compare the chromosome error rate among oocytes from stimulated ovaries after retrieval of 1-5 oocytes, 6-10 oocytes, and >10 oocytes.

DESIGN

Retrospective cohort study.

SETTING

A university-based human genetic institute in collaboration with a private fertility center.

PATIENT(S): Nine hundred thirty-three women undergoing intracytoplasmic sperm injection (ICSI) with a poor prognosis.

INTERVENTION(S): Oocyte collection with ovarian stimulation. Polar body testing of ICSI oocytes for common chromosome errors.

MAIN OUTCOME MEASURE(S): Chromosome error rate in oocytes, as determined by five-color fluorescence in situ hybridization.

RESULT(S): In women less than 35 years and women between 35 and 40 years undergoing the first ICSI cycle, oocytes from the high-yield group had an increased likelihood for detectable chromosome errors (50.9% and 54.6%, respectively), compared to the intermediate-yield group (34.9% and 43.8%) and the low-yield group (23.3% and 41.2%). The overall high rate (>or=50%) of chromosomally abnormal oocytes in women more than 40 years appeared to be mainly due to the maternal age effect and increased only slightly with oocyte yield.

CONCLUSION(S): Oocyte yield may be considered as an indicator of ovarian response to hormone stimulation. In women up to 40 years a high yield of oocytes after superovulation is associated with an increased chromosome error rate.