Is fine morphology of the human sperm nuclei affected by in vitro incubation at 37 degrees C?

Objective: Incubation of ejaculated spermatozoa at 37 degrees C is recommended for IVF-intracytoplasmic sperm injection. Preselection of sperm cells with morphologically normal nuclei before microinjection, adapted in our laboratory, is usually a time-consuming procedure. Therefore, we aimed to verify whether incubation at 37 degrees C could affect the morphologic integrity of sperm nuclei.

Does the presence of nuclear vacuoles in human sperm selected for ICSI affect pregnancy outcome?

Background: To verify whether or not microinjection of sperm with a normal nuclear shape but large vacuoles affects IVF-ICSI pregnancy outcome.

Methods: A comparative study testing IVF outcome parameters of IVF-ICSI, based on morphological selection of spermatozoa with normal nuclei against those based on microinjection of sperm with a normal nuclear shape but large vacuoles. An experimental group, including 28 IVF-ICSI cycles, where only embryos obtained from microinjection of spermatozoa with a normal nuclear shape but large vacuoles were transferred, was matched with a control group, including 28 IVF-ICSI cycles, where only embryos obtained from microinjection of spermatozoa with a strictly defined morphologically normal nuclear shape and content were transferred.