Evaluation of most part of the fetal anatomical structures is feasible with high accuracy in the first trimester. Visualization of the majority of the targeted fetal organs improves from 11 to 13 weeks.

NT thickness does not show a significative increase in those women who subsequently develop GDM. Therefore, NT assessment does not prove to be an useful ultrasound parameter for predicting GDM onset during pregnancy.

Recent reports suggest that maternal serum levels of pregnancy-associated plasma protein A (PAPP-A) may predict perinatal outcome. PAPP-A is a syncytiotrophoblast derived protease for insulin-like growth factor binding protein (IGFBP4); its protease activity cleaves complexed growth factor binding protein increasing insulin-like growth factor I (IGF-I) bioavailability. The aim of our study was to evaluate the correlation between maternal PAPP-A serum levels and neonatal growth. We analysed 100 full term and preterm (30-36 weeks) small for gestational age (SGA) and adequate for gestational age (AGA) babies whose mothers had been tested for serum PAPP-A at 11-13 weeks of gestation. We found a significant positive correlation between maternal PAPP-A and neonatal weight, length, and head circumference at birth in both term and preterm infants. Low maternal PAPP-A serum levels (maternal PAPP-A < 0.5) were associated with small for gestational age neonates. A significant positive correlation was also evident between maternal PAPP-A and babies' growth parameters at 6 months of age. Our results suggest that maternal levels of PAPP-A in early pregnancy affect growth during both foetal and early postnatal life.

What's already know about this topic? Abnormalities of the choroid plexus have only been reported in association to holoprosencephaly, so the description of the ‘bat sign’ in the first trimester is novel and could be important as a marker of some rare chromosomal abnormalities, in this case trisomy 22. What does this study add? Our data is another remarkable proof of the importance of a morphological investigation of the fetus in the first trimester.

A combined screening for Down syndrome and other aneuploidies can be offered to pregnant women between 11 +0 and 13 +6 weeks of gestation. It includes ultrasound evaluation of nuchal translucency (NT) and maternal plasma assay of f-βhCG and PAPP-A (Bindra et al., 2002;Nicolaides 2003Nicolaides , 2005. The technique of NT measurement should follow exact criteria: the sonographer should obtain an image of the fetal head, neck and upper part of the thorax and should enlarge it as much as 3/4 of the screen. To avoid over-or underestimating NT thickness, the fetus should be in a neutral position, neither too extended nor flexed. It is very important to distinguish fetal skin from the amniotic membrane and this can be obtained by waiting for the fetus to move spontaneously or by gently pressing on maternal abdomen (Pandya et al., 1995;Nicolaides et al., 1998;Evans et al., 2007).Active fetal movements are one of the factors that can help the operator to acquire rapidly the best view for NT assessment. We hypothesize that fetal movement may be related to the fetal metabolic status.Glucose, which passes from the maternal compartment through the placenta by direct diffusion, represents the most important metabolic substrate for the fetus, and it is totally dependent on maternal glycemia (Weissgerber and Wolte, 2006). The circadian glycemic profile in normal pregnant women is characterized by postprandial prolonged hyperglycemia (facilitated anabolism) that permits transfer of glucose to the fetus despite the mother's intermitting feeding (Herrera, 2002). Glycemic mean levels during the day are similar to nonpregnant condition as hyperglycemic postprandial periods are counterbalanced by hypoglycemic ones far away from the meals (Yogeu et al., 2004).Because we had the impression that NT thickness assessment was faster when done early in the morning than later, we hypothesized that maternal glucose intake may affect time for NT measurement.We enrolled a total of 220 women with singleton pregnancy booked for first trimester screening for Down syndrome and other aneuploidies from