Reading the observational documentation of multiple parameters of cardiovascular function in twin pregnancies by Ghi et al we would like to raise a serious concern. They observed deterioration during pregnancy in several parameters of maternal cardiac systolic function that remained deteriorated at 6 months postpartum. If this will indeed be supported by other studies, it would have immense repercussions, almost as far as justifying early reduction of 1 embryo in twin pregnancies to save mothers’ health.

Twin pregnancy has been acknowledged by the American Society for Reproductive Medicine as carrying high risk, in conjunction with its increased rate in pregnancies using assisted reproduction technology (ART). The reported worldwide rates of twin gestations following ART was up to 22% in 2006, which has led to revised policy of transferring only 1 embryo under most ordinary circumstances. Nevertheless, it appears that clinicians are reluctant to revise their policy, as among 134,381 ART transfer cycles performed in 2012 in the United States, 51,262 resulted in live births, of which 13,123 (25.6%) were twins.

Up until the current study by Ghi et al, most elements of high risk in twin gestations regarded the neonates primarily due to prematurity. Increased maternal complications such as preeclampsia and gestational diabetes mellitus were limited to the gestational or the postpartum period. With this new contribution the balance shifts somewhat toward long-term maternal risks. Hence we would like to suggest the following 2 indispensable steps. First, Ghi et al should follow their own suggestion to capture the women prior to pregnancy (a good starting group would be ART candidates, of whom a significant proportion would later carry twins). This may indeed prove the parameters of the first trimester as better than prepregnancy, with the postpartum findings being a mere return to baseline. Second, they should examine to the same depth of analysis a cohort of singleton pregnancies. If singleton pregnancies also share this character of deterioration, then the whole issue may represent either an artifact of measurements or a true tendency, regardless of the number of fetuses, but would not carry any practical conclusions.

All told, after raising this red flag of possible warning, the issue should be addressed promptly.