Comparison of embryo morphokinetics after in vitro fertilization-intracytoplasmic sperm injection in smoking and nonsmoking women

Objective To evaluate the impact of female smoking on early embryo development in vitro using a time-lapse system. Design Retrospective analysis of prospectively collected database. Setting Assisted reproductive technology (ART) program. Patient(s) A total of 135 infertile couples undergoing IVF-intracytoplasmic sperm injection (ICSI) cycle. Intervention(s) Embryo culture in a time-lapse incubator (Embryoscope, Unisense Fertilitech). Main Outcome Measure(s) Embryo morphokinetic parameters. Result(s) Of 135 women, 139 and 729 oocytes were cultured in 23 smokers and 112 nonsmokers, respectively. Basal characteristics and ovarian stimulation parameters were comparable in both groups. Serum antimüllerian hormone level and antral follicle count were significantly lower in smokers than in nonsmokers. Conventional embryologic parameters were comparable in both groups, but time-lapse analysis showed that most cleavage events occurred significantly later in smokers than in nonsmokers, leading to poor cycle outcome in smokers. Conclusion(s) Female smoking impairs early embryo development, as reflected by time-lapse analysis. This might contribute to the dramatic decrease in pregnancy rates (PRs) in smokers undergoing IVF. Time lapse is a useful tool for the identification of deleterious components impairing early embryo development.