Fertilization and early embryology: Improved cleavage rate of human embryos cultured in antibiotic-free medium

Abstract

Retarded development and blastomere fragmentation of human preimplantation embryos represent a common phenomenon in in-vitro culture systems. Even though media composition is generally formulated to meet embryo nutritional requirements, the influence of antibiotic supplementation has not been investigated thoroughly. The present study was performed to evaluate the effects of antibiotics on embryo morphology and growth in modified culture media. A total of 196 zygotes from 18 couples was cultured in three different media: (i) conventional medium (n = 99, control group); (ii) medium modified with half the standard antibiotic concentration (n = 54; and (iii) antibiotic-free medium (n = 43); 49 embryos from the control group were selected at the zygote stage and transferred to the patients on day 2. The remaining 147 zygotes were cultured to the blastocyst stage for cryopreservation; their morphology and cell number were assessed daily at 40, 64, 88 and 112 h post-insemination. Overall cleavage rate was 95% and embryo scoring revealed 91% grade 1 embryos throughout the culture period in the three media. Significantly higher cleavage rates were obtained in the antibiotic-free medium at each observation, including the blastocyst stage, when compared to the other two groups. In addition, no notable improvement was observed in the embryos cultured in a reduced concentration of antibiotics. In conclusion, antibiotic supplementation of media has an adverse effect on the growth rate of preimplantation embryos, even in reduced concentrations, suggesting that antimicrobial drugs may interfere with the timing of cleavage events either by delaying or blocking embryo development.

Quantitative and qualitative analysis of microorganisms in an assisted reproductive technology facility

“…Multiple studies have documented the potential cytotoxic affects of aminoglycoside and b-lactam antibiotics (8)(9)(10)(11). Furthermore, the development of resistant strains and antibiotic-induced release of endotoxin are points of concerns associated with antibiotic usage.…”

Antibiotics supplemented culture media can eliminate non-specific bacteria from human semen during sperm preparation for intra uterine insemination

“…According to some authors the recommended dose for human semen is 100 IU penicillin and 50 mcg streptomycin. [7] The long term use of the same antibiotic may lead to emergence antibiotic resistant varieties. The resistance of E. coli to both penicillin and streptomycin used in culture media has been reported.…”

“…It has been reported that antibiotic supplementation of culture media has an adverse effect on the growth rate of pre-implantation embryos. [7] Hence, ready to use culture media are available with antibiotics or without antibiotics.…”

Efficacy of two sperm preparation techniques in reducing non-specific bacterial species from human semen

“…Indeed, the elimination of penicillin and streptomycin from the media resulted in an improved cleavage rate. [37] Faster cleaving embryos have been clearly demonstrated to be more capable of implantation in animal species. [3839] A strong positive correlation was found between cleavage delay and chromosomal abnormalities.…”