Shortened exposure of oocytes to spermatozoa improves in-vitro fertilization outcome: a prospective, randomized, controlled study

Abstract

A prospective, randomized study of 158 patients undergoing in-vitro fertilization (IVF) and embryo transfer was conducted to evaluate whether a shortened exposure of oocytes to spermatozoa enhances oocyte development, and subsequently influences the IVF outcome. A comparison was made between conventional treatment time and shorter exposure of retrieved oocytes to spermatozoa. Fertilization and cleavage rates, embryo quality, implantation and pregnancy rates in the study group (short exposure) versus controls (standard IVF procedure) were evaluated. Fertilization (56 versus 61%) and cleavage rates (96 versus 92%) were similar in the two groups respectively. However, embryo quality was significantly higher in the study group (P < 0.05). Moreover, the pregnancy and implantation rates were significantly increased (42.4 versus 26% per embryo transfer, and 16 versus 10% respectively; P < 0.05). Our results demonstrated that shorter exposure of oocytes to spermatozoa is superior to the standard time in IVF and may have a favourable effect on implantation rates by improving embryo quality.

A Randomized Study Comparing the Effect of Standard Versus Short Incubation of Sperm and Oocyte on Subsequent Pregnancy and Implantation Rates Following in Vitro Fertilization Embryo Transfer

“…The data do not seem to corroborate the conclusions of Dirnfeld et al and Gianaroli et al that short incubation improves the implantation rate [4,5]. However, differences in experimental design could account for the different conclusions.…”

“…We used communal growth dishes instead of microdroplets, because Almagor et al reported higher PRs after communal growth [1]. Also, our incubation time 2 h versus 1 h for Gianaroli et al [5] and 3 h for Dirnfeld et al [4].…”

“…Dirnfeld et al found that decreasing the incubation period from 16 to 3 h significantly improved implantation rates [4]. They speculated that shorter exposure of the oocyte to sperm prevented zona hardening.…”

The value of second polar body detection 4 hours after insemination and early rescue ICSI in preventing complete fertilisation failure in patients with borderline semen

“…Shortened exposure of oocytes to spermatozoa has been implemented in IVF practice for different purposes. It was reported that shortened exposure of oocytes to spermatozoa improved embryo quality by preventing the negative effects of oxygen free radicals produced by the spermatozoa during the insemination process (Dirnfeld et al 1999;Kattera and Chen 2003). Our previous observations demonstrated that the duration of spermatozoon-oocyte co-incubation did not affect fertilisation, embryo quality, clinical pregnancy or implantation rates (Dai et al 2012).…”

Analyzing Factors Affecting the Success Rate of Frozen–Thawed Embryos

“…In vitro fertilization technique was applied as previously described (7). ICSI procedure was carried out according to Van Steirteghem et al (8) on the Nikon microscope by using Nomarski modulation optics with two three-dimensional manipulators (Narishige, Tokyo, Japan) with modifications as previously described (9).…”