Integrating insulin into single-step culture medium regulates human embryo development in vitro.

OBJECTIVE: To evaluate the effect of supplementing single-step embryo culture medium with insulin on human embryo development.

DESIGN: Comparative study.

SETTING: Two private centers.

PATIENT(S): The study involved a sibling oocyte split of 5,142 retrieved oocytes from 360 patients.

INTERVENTION(S): Sibling oocytes split after intracytoplasmic sperm injection for culture from day 0 through day 5 or 6 in insulin-supplemented or control medium. Women were split to receive their embryos from insulin-supplemented or control medium.

MAIN OUTCOME MEASURE(S): Clinical pregnancy rate.

RESULT(S): There were significantly higher rates of clinical, ongoing, and twin pregnancies in the insulin-supplemented arm than in the control arm. On day 3, embryo quality and compaction were higher in insulin-supplemented medium. On day 5, insulin supplementation showed higher rates of blastocyst formation, quality, and cryopreservation.

CONCLUSION(S): Insulin supplementation of single-step embryo culture medium from day 0 through day 5 or 6 improved clinical pregnancy rate and human embryo development. However, these findings need further confirmation through a multicenter randomized controlled trial that may include other patient populations and different culture media.