Normal and abnormal development of the fetal anterior fontanelle: a three-dimensional ultrasound study.

OBJECTIVES: To describe the methodology for correct visualization of the anterior fontanelle using three-dimensional ultrasound, to report its normal development during gestation, and to compare this with abnormal development. METHODS: This was a cross-sectional prospective evaluation of development of the anterior fontanelle in a series of 78 normal fetuses and 47 fetuses with congenital anomalies between 12 and 38 weeks of gestation. The anterior fontanelle was visualized in a mid-sagittal view of the fetal head, preferably with a pocket of fluid between the fetal head and the uterine wall, to ensure an optimal acoustic window. Visualization using volume contrast imaging mode in the coronal plane (VCI-C) was preferred to static acquisition of three-dimensional (3D) volumes, as the former allows real-time evaluation of the 3D image. Anteroposterior and laterolateral diameters, perimeter and area of the fontanelle were measured offline, with the diameters normalized for biparietal diameter and the perimeter and area normalized for head circumference. The variables were then regressed against gestational age. RESULTS: The best fitting regression model to describe the relationships between the fontanelle anteroposterior diameter and area and gestational age was a quadratic one, whereas a simple linear model fitted all remaining variables. All variables showed a positive or biphasic correlation with advancing gestational age, but a negative one after normalization for biparietal diameter or head circumference. Twenty of the 47 fetuses with abnormalities had abnormal (18 enlarged and two reduced) fontanelle dimensions, particularly those with chromosomal or non-chromosomal syndromes, primary or secondary cardiac overload, primary skeletal dysplasias or central nervous system malformations. Hydrops was not associated with abnormal fontanelle dimensions. CONCLUSIONS: We have described the methodology to obtain correct visualization of the fetal anterior fontanelle. The actual size of the fontanelle increases during gestation, while its size in relation to the volume of the fetal head diminishes, possibly due to the rapid development of the brain hemispheres and the consequent outward growth of the calvarial bones. The fact that enlarged fontanelle dimensions may be associated with certain fetal abnormalities may be employed advantageously in the differential diagnosis of some syndromic conditions in utero.

The role of spatio-temporal image correlation (STIC) with tomographic ultrasound imaging (TUI) in the sequential analysis of fetal congenital heart disease.

OBJECTIVE: Spatio-temporal image correlation associated with the tomographic ultrasound imaging mode (TUI-STIC) is a new modality that allows a complete sequential analysis of cardiac structures to be displayed on a single panel by showing all echocardiographic transverse views at the same time. The aims of this study were to identify the best settings for displaying the classic echocardiographic views at different gestational ages and to investigate the role of TUI-STIC in the sequential segmental analysis of complex congenital heart disease (CHD). METHODS: Four-dimensional volumes from 103 cases of confirmed fetal CHD diagnosed and managed at our referral center were evaluated using TUI-STIC. To select the best interslice distance for adequate display of the central cardiovascular connections, each volume was opened and the TUI mode activated, having as a reference the apical four-chamber view. The number of slices was set at nine. The volume was then scrolled until the most significant echocardiographic views were displayed on the screen windows. Then, if too many windows showed intermediate non-diagnostic views, the slice distance was adjusted finely until all key echocardiographic views showed up in the various windows. The interslice distance was regressed against gestational age and the best-fitting curve was identified. RESULTS: A sequential segmental analysis could be shown with TUI-STIC in all cases. A linear regression equation best fitted the correlation between interslice distance and advancing gestational age (r(2) = 0.9042), with the mean interslice distance being 2.7 (SD, 0.3) mm at 19-23 gestational weeks, and 4.0 (SD, 0.4) mm at 30-33 weeks. These settings allowed a complete sequential analysis in all cases. CONCLUSIONS: TUI-STIC allows a complete sequential analysis of CHD in the fetus. The most suitable interslice distances for all gestational ages could be identified. These data may be used while adopting this imaging modality in the four-dimensional evaluation of fetal CHD.

Cavernous lymphangioma of the face and neck: prenatal diagnosis by three-dimensional ultrasound.

Cavernous lymphangiomas are characterized by penetration through the subcutaneous areas between the muscular septa and represent rare variants of the more common superficial lymphangioma. Although frequently described in the fetus when involving the posterior aspect of the neck (i.e. cystic hygroma), involvement of the craniofacial region is rare. We describe the prenatal findings in a case of cavernous lymphangioma of the fetal face and neck, which extended caudally to envelop the larynx and the trachea. The anomaly was assessed by two- and three-dimensional (3D) ultrasound. The latter approach was used thoroughly both during counseling with the couple and during consultation with the pediatric surgeon. This case report confirms the usefulness of the 3D approach in the management of rare fetal anomalies. In particular, the possibility of navigating the volume facilitated consultation with the pediatric surgeon and counseling of the parents.

Hypoplastic left heart syndrome associated with left ventricle-coronary artery-pulmonary artery fistula: prenatal diagnosis and histological correlation.

We describe an unusual case of left ventricle-left coronary artery-pulmonary artery fistula associated with hypoplastic left heart syndrome (HLHS) and a ventricular septal defect, in which findings on echocardiography and histological analysis were correlated. The diagnosis was made at 22 weeks of gestation. We speculated that the presence of the fistula was the primary cause of the HLHS due to the existence of the ventricular septal defect that nullified the intraventricular pressure gradient, which is typical of hypoplastic ventricles and thought to be responsible for the secondary development of fistulas in other cases.

The role of tissue harmonic imaging in fetal echocardiography.

OBJECTIVE: To define the role of tissue harmonic imaging (THI) in fetal echocardiography. METHOD: Three trials were conducted in a tertiary referral center: Study A was a prospective randomized trial including 50 women referred for fetal echocardiography. Those allocated to Arm 1 underwent conventional fundamental frequency ultrasound (FFU) and those allocated to Arm 2 underwent THI. Study B was conducted in 21 patients who were obese or overweight with significant weight gain in pregnancy. In these patients, both THI and FFU echocardiography were performed and compared. In Study C, THI was employed as a second-line rescue technique in cases of inadequate or incomplete examination by FFU. A subjective scoring system was used by a reviewer who had not performed the examinations to assess the comprehensiveness of the examination and the image resolution. The reviewer was blinded to the image modality. RESULTS: In Study A, no difference was found in the diagnostic accuracy between THI and FFU echocardiography but the resolution was significantly poorer in the THI arm. In studies B and C, THI performed significantly better than FFU (P < 0.001). CONCLUSIONS: THI echocardiography seems to be the best technique to employ in obese women and in those in whom FFU fails to provide diagnostic information. However, due its poorer resolution in women of average weight, FFU echocardiography should remain the technique of choice.

Prenatal ultrasound diagnosis of Nager syndrome.

Nager syndrome, or acrofacial dysostosis, is a rare malformation complex characterized by facial anomalies (external ear abnormalities and micrognathia) and limb defects (radial hypoplasia and absence of the thumb and/or other digits). Since its first description in 1948, more than 80 cases have been reported in the pediatric literature. However, there is only one previous report on the prenatal recognition of the syndrome, which was at 30 weeks of gestation. We report here a further case of Nager syndrome, prospectively diagnosed at 23 weeks of gestation.

[Hormone therapies in pregnancy]. / Terapie ormonali in gravidanza.

Maternal endocrine disorders can have detrimental effects on the fetus and the pregnancy can affect the course of a pre-exisiting endocrinopathy or induce the onset of one of these disorders. Therapies for endocrine disorders are not always safe to administer during pregnancy. Before administering any therapy to the mother, the effects on the fetus, the degree of placental trespassing as well as the potential damaging effects must be assessed. An accurate evaluation of the risks/benefits of any drug to be used on the mother is needed, assessing above all a potential theratogenic effect. In this review, the incidence of the main endocrine disorders, their evolution during pregnancy, their effects on mothers and fetuses and new acquisition on the treatment during pregnancy are discussed.