Pre-decondensed sperm head injections into female pronuclei result in chromosomal mingling, zygotic cleavage, and adequate embryonic and fetal development up to delivery of healthy offspring: a novel method of assisted syngamy

Investigation of the developmental potential post‐injection of a pre‐decondensed or non‐pre‐decondensed sperm head into the female pronucleus of a pre‐activated oocyte. Rat pre‐activated oocytes were treated with intrapronuclear pre‐decondensed sperm head injections (IPSHI) (n = 133) or intrapronuclear non‐pre‐decondensed sperm head injections (INPSHI) (n = 138). All injected oocytes were transferred to pseudopregnant female recipients. Rat IPSHI techniques resulted in the delivery of five healthy offspring. Rat INPSHI techniques did not result in any pregnancies. Rat IPSHI techniques can result in delivery of healthy offspring. Successful performance of human IPSHI techniques might serve as a novel method to manage cases of intracytoplasmic sperm injection failure due to lack of development of male pronucleus or due to failure in pronuclei fusion.