Litzky JF, et al. - Given the increasing usage of blastocyst transfer (BT), at day 5–6 post-fertilization, partially due to improved pregnancy outcomes over cleavage-stage transfer (CT, day 2–3), researchers investigated BT’s effects on birthweight. They identified an increase in birthweights following BT, however, the increase was not seemed to be clinically relevant, as there were no differences in rates of macrosomia or low birthweight (LBW). The findings are thereby clinically reassuring and show that the increasing use of BT may not further reduce the on average lower birthweights seen in IVF infants compared to their naturally conceived peers.