Does culture medium influence offspring birth weight?

Objective: To determine whether the type of medium used to culture human embryos in vitro influences neonatal birth weight after IVF/intracytoplasmic sperm injection (ICSI). Design: A prospective study and a retrospective study. Setting: Private assisted reproduction center. Patient(s): The prospective study included 449 IVF/ICSI cycles from August to December 2008. The retrospective analysis was performed for 2,518 IVF/ICSI cycles from October 2006 to December 2010. Intervention(s): In the prospective study, patients were randomized for embryo culture in Cook or Vitrolife medium. The retrospective study was performed with three different culture media (MediCult, Cook, and Vitrolife). Main Outcome Measure(s): Mean birth weight, adjusted for gestational age and gender (z score) of newborns. Result(s): In the prospective study, the average z score was -0.19 +/- 0.85 in Cook and 0.08 +/- 1.40 in Vitrolife. In the retrospective study, the z scores obtained in each group were as follows: Cook, -0.14 +/- 0.96; MediCult, 0.06 +/- 1.13; and Vitrolife, 0.03 +/- 1.05. No significant differences were observed regarding the birth weight of children born in the different groups in both studies. Conclusion(s): The results do not show any relationship between the medium used for in vitro culture and mean birth weight adjusted for gestational age and gender of singletons born after IVF/ICSI. (C)2013 by American Society for Reproductive Medicine.