G. Rembouskos

Likelihood ratio for trisomy 21 in fetuses with absent nasal bone at the 11-14-week scan

To update the likelihood ratio for trisomy 21 in fetuses with absent nasal bone at the 11–14‐week scan.

Absent nasal bone at 11–14 weeks of gestation and chromosomal defects

To examine the association between absence of the nasal bone at the 11–14‐week ultrasound scan and chromosomal defects.

Fetal nasal bone length in chromosomally normal and abnormal fetuses at 11- 14 weeks of gestation

Objective: To determine the value of measuring fetal nasal bone length at 11-14 weeks of gestation in screening for chromosomal defects. Methods: The fetal profile was examined and the nasal bone length was measured in 1092 fetuses immediately before chorionic villous sampling for karyotyping at 11-14 weeks of gestation. Results: The median gestation was 12 (11-14) weeks. The fetal profile was successfully examined in all cases. The fetal karyotype was normal in 955 pregnancies and abnormal in 137, including 79 cases of trisomy 21. In the chromosomally normal group, the fetal nasal bone length increased significantly with crown-rump length (CRL) from a mean of 1.3 mm at a CRL of 45 mm to 2.1 mm at a CRL of 84 mm. In 54 of the 79 (68.4%) cases of trisomy 21, the nasal bone was absent. In the 25 cases with present nasal bone, the nasal bone length for the CRL was not significantly different from normal. Similarly, there were no significant differences from normal in the nasal bone length of fetuses with other chromosomal defects. Conclusions: At 11-14 weeks of gestation, the nasal bone length of chromosomally abnormal fetuses is not significantly different from normal.

Disorders of prosencephalic development

Abnormal ventral induction may result in disorders of formation, cleavage, and midline development of prosencephalic structures. Holoprosencephaly is a developmental field defect of impaired cleavage of prosencephalon. The most widely accepted classification of holoprosencephaly recognizes three major varieties: the alobar, semilobar and lobar types, according to the severity of the malformation. The brain malformations, characterized by the fusion of the cerebral hemisphere along the midline are commonly associated with facial anomalies.

Single umbilical artery at 11–14 weeks' gestation: relation to chromosomal defects

To determine the possible association between single umbilical artery (SUA) at 11–14 weeks of gestation and the incidence of chromosomal abnormalities.

Maxillary length at 11-14 weeks of gestation in fetuses with trisomy 21

To determine the value of measuring maxillary length at 11–14 weeks of gestation in screening for trisomy 21.

Assessment of the fetal nasal bone at 11–14 weeks of gestation by three-dimensional ultrasound

To evaluate the benefit of three‐dimensional (3D) ultrasound in the examination of the fetal nasal bone at 11–14 weeks of gestation.

Fetal cardiac evaluation at 11–14 weeks by experienced obstetricians in a low‐risk population

The aim of this study was to evaluate the detection rate of congenital heart diseases (CHD) in a low‐risk population by performing cardiac evaluation during the first‐trimester screening for chromosomal abnormalities. In this context, the role of four‐chamber view, tricuspid regurgitation and abnormal ductus venosus flow in the screening for cardiac anomalies in a low‐risk population was also investigated.

Fetal interrupted aortic arch: 2D-4D echocardiography, associations and outcome

To analyze fetal two‐dimensional (2D) echocardiographic characteristics of interrupted aortic arch (IAA) and its different types, to explore whether the use of 4D ultrasound with B‐flow imaging and spatiotemporal image correlation (STIC) can improve prenatal diagnostic accuracy, and to describe associations and outcome.

Ear length in trisomy 21 fetuses at 11-14 weeks of gestation.

To determine the value of measuring fetal ear length at 11–14 weeks of gestation in screening for chromosomal defects.