A study regarding birth weight of children born after embryo culture in Vitrolife G-media and in Cook’s sequential culture media was published in 2010 by Dumoulin et al.

Culture media have effect on birth weight
The study showed that medium used for culturing embryos during the first few days after fertilisation significantly affects the birth weight of resulting singletons. Children born after culture in Vitrolife media were closer to normal birth weight compared to the children conceived after embryo culture in Cook media. Time of onset of this growth difference however was still unknown. Therefore, Dumoulin et al. conducted a follow up study to investigate the fetal growth of the singletons.

Summary of follow-up study presented at ESHRE 2011
Fetal crown rump length (CRL) and fetal β-hCG were measured between 8 weeks and 20 week of gestation of all singleton pregnancies during the study period, 2003-2006.

In the investigated series of singletons, fetal β-hCG measured at 12 weeks of pregnancy was found to be significantly higher in the Vitrolife group. hCG is known to play a major role in early human development, especially in the first trimester, but also during the remainder of pregnancy according to growing experimental evidence. At 20 weeks of gestation, a significantly larger than expected fetus was seen in the Vitrolife group when compared to the Cook group. This corresponds to the significantly higher birthweight in the Vitrolife group discovered in our previous study. The data of this study show that differences in fetal development after culture of embryos in different IVF media are apparent already during the second trimester of pregnancy.

Read full abstract here.