Strengths and Limitations
Strength of our study is the inclusion of a low risk population; this
could have reduced population selection bias. Even though the study
involved more than one Centre, a single protocol was shared and the
management of all the patients was homogeneous. In addition, the long
term follow-up of children was crucial because several postnatal
diagnosis were made after 6 months of age.
A possible limitation of the study is that not all patients underwent
fetal karyotyping and CGH-array. In particular, postnatal genetic
examination of liveborns who showed normal long term follow up was not
performed and this could lead to the underestimation of genetic
disorders.