Strengths and limitations
Strengths of our study include, first, longitudinal cardiovascular assessment in pregnancies affected only by GDM without the confounding effect of pregestational diabetes, which could potentially affect early embryonic development and alter cardiac morphogenesis and placental development. Second, by performing detailed cardiac functional evaluation from fetal to postnatal life, we were able to detect subtle fetal cardiac functional changes and track these through the first year of life. Cardiac measurements were performed using advanced echocardiographic modalities and following strict imaging protocols. Third, trained fellows blinded to maternal characteristics performed analysis to avoid any bias in the results. The main limitation of the study is that fetal speckle tracking analysis was performed using one analysis platform and as such the measurements may not be generalizable to those generated by other software(15). Another limitation was that although we aimed to have the same interval after delivery for postnatal cardiac assessment for the GDM and controls, this was not achieved and there was a mean difference of 4 months between the groups; however, we accounted for this discrepancy in the multivariable analysis.