Transvaginal sonographic diagnosis of short-rib polydactyly dysplasia at 13 weeks' gestation

Additional first-trimester ultrasound markers

The first trimester (11-13 +6 weeks) ultrasound examination is useful for several reasons: determination of an accurate date of confinement, diagnostic purposes, and screening for fetal defects. Nuchal translucency measurement combined with maternal serum markers (free b-human chorionic gonadotropin and pregnancy-associated plasma protein A) is the mainstay of first-trimester screening for chromosomal defects. However, over the past decade additional ultrasound markers have been developed that improve the performance of this type of screening. The novel markers include evaluation of the nasal bone, fronto-maxillary angle measurement, and Doppler evaluations of the blood flow across the tricuspid valve and in the ductus venosus.

First Trimester Ultrasound Screening: An Update

For many years, the main use of ultrasound in the first trimester of pregnancy was to confirm viability and to establish gestational age. Indeed, the crown-rump length measurement in the first trimester remains the most accurate method to estimate the gestational age even today. However, improvements in ultrasound equipment and improvement in our understanding of normal and abnormal fetal development allows us now to perform a much more complete first trimester fetal evaluation. This pertains not only to the diagnosis of fetal anomalies but also to screening for fetal defects. The combination of the nuchal translucency measurement and maternal serum biochemistries (free β-hCG and PAPP-A) has been shown to be an extremely efficient way to screen for fetal aneuploidy. The addition of other first trimester markers such as the nasal bone evaluation, frontomaxillary facial angle measurement, and Doppler evaluation of blood flow across the tricuspid valve and through the ductus venosus improves the screening performance even further by increasing the detection rates and decreasing the false positive rates. Several of the first trimester markers also are useful in screening for cardiac defects. Furthermore, significant nuchal translucency thickening has been associated with a variety of genetic and nongenetic syndromes. A recently described first trimester marker called the intracerebral translucency appears to hold great promise in screening for open spine defects. Finally, it appears that a first trimester evaluation (uterine artery Doppler and the measurement of certain biochemical markers in the maternal serum) significantly improves the assessment of the risk of preeclampsia.

First-trimester ultrasound diagnosis of skeletal dysplasia associated with increased nuchal translucency thickness

A series of five cases of skeletal dysplasia is reported in which the diagnosis was reached at the 11-14-week routine ultrasound examination in our referral center. All five cases had increased nuchal translucency thickness (NT) associated with bone abnormalities. We review the current literature on skeletal dysplasia in the first trimester of pregnancy associated with increased NT.

First trimester ultrasonography in screening and detection of fetal anomalies

An obstetrical ultrasound examination provides invaluable information regarding the fetus. Until the mid-1980s, ultrasound in the first trimester was limited to localization of the pregnancy, establishing viability, and accurate dating. With the advent of high-resolution ultrasound and transvaginal scanning, a significant amount of information about the fetus can be gained and provided to the patient at a very early stage in gestation. This article provides an overview of the role of first trimester (11-13 + 6 weeks' gestation) ultrasound in screening and diagnosis of fetal anomalies. The first trimester is an ideal time for screening for aneuploidy, primarily due to the advantages that nuchal translucency (NT) measurement provides. NT measurement is also useful in establishing the risk of congenital cardiac disorders and a number of genetic and non-genetic syndromes. Significant NT thickening is associated with an increase in perinatal morbidity and mortality. Potential mechanisms resulting in increased NT are discussed. A number of new ultrasound markers for fetal aneuploidy have been investigated over the past several years, some of which appear to improve the screening efficacy of early ultrasonography. The role of these is reviewed. A number of fetal anomalies can now be consistently diagnosed in the first trimester. Their appearance at this early gestational age is discussed as well. It is clear that, data obtained by first trimester ultrasound are useful in counseling expectant parents and in planning the appropriate follow-up.

Short-Rib-Polydactyly Syndrome Presenting with Increased Nuchal Translucency in a High-Risk Family

Short-rib-polydactyly syndrome represents a group of rare, autosomal recessive, lethal skeletal dysplasias characterized by hypoplastic thorax, short ribs, short limbs, polydactyly, and visceral abnormalities. We describe an affected fetus from a high-risk family presenting with increased nuchal translucency at 13 weeks of pregnancy. The diagnosis was established in the 2nd trimester.

Increased first-trimester fetal nuchal translucency thickness in association with chondroectodermal dysplasia (Ellis-Van Creveld syndrome)

Increased nuchal translucency thickness (NT) is an established sonographic marker of fetal chromosomal abnormality. Several structural fetal defects and genetic syndromes including a range of skeletal dysplasias have been reported in association with increased NT. We report the first case of fetal Ellis-Van Creveld syndrome presenting as raised fetal NT at 13 weeks' gestation. Ultrasonography at 18 weeks' gestation demonstrated a narrow thorax, marked shortening of the long bones with bowed femora and hexadactyly of hands and feet. Pregnancy was terminated at 23 weeks' gestation. The postmortem radiological examination revealed short and bowed long bones with rounded metaphyses, postaxial polydactyly of hands and feet, short ribs and narrow thorax. The acetabular roofs were horizontal with medial and lateral spurs. This case adds a further type of severe skeletal dysplasia to the list of genetic syndromes which may present as increased fetal NT in the late first trimester.

Increased nuchal translucency with normal karyotype

Increased fetal nuchal translucency (NT) thickness between 11 and 14 weeks' gestation is a common phenotypic expression of chromosomal abnormalities, including trisomy 21. However, even in the absence of aneuploidy, nuchal thickening is clinically relevant because it is associated with an increase in adverse perinatal outcome caused by a variety of fetal malformations, dysplasias, deformations, dysruptions, and genetic syndromes. Once the presence of aneuploidy is ruled out, the risk of perinatal outcome dose not statistically increase until the nuchal translucency measurement reaches 3.5 mm or more (>99th percentile). This increase in risk occurs in an exponential fashion as the NT measurement increases. However, if the fetus survives until midgestation, and if a targeted ultrasound at 20 to 22 weeks fails to reveal any abnormalities, the risk of an adverse perinatal outcome and postnatal developmental delay is not statistically increased.

Fetal cardiac anomalies and genetic syndromes

Cardiac anomalies may occur in isolation or can be part of a genetic syndrome. In this article, we describe some of the genetic syndromes commonly associated with cardiac anomalies where there are other sonographic features that may aid accurate prenatal diagnosis.

A new report of mesomelic camptomelia, polydactyly and Dandy-Walker complex in siblings

Two male siblings with several malformations are reported. The anomalies detected in both fetuses were mesomelic camptomelia, postaxial hexadactyly and Dandy-Walker complex. There was only one similar previous report in the literature. This combination could represent a specific pattern of malformation or a new syndrome, with different variants. The parents' consanguinity and the recurrence in a subsequent pregnancy suggest an autosomal recessive inheritance pattern.

First-trimester ultrasound

There has been an increase in the use of fetal ultrasound in the first trimester. This article reviews the published literature with emphasis on fetal nuchal translucency (NT). When measured according to well-defined guidelines, increased NT identifies about 80% of chromosomal anomalies for a false-positive rate of about 5%. Increased NT may indicate the presence of structural defects or genetic disorders, and it is relatively frequently seen in monochorionic pregnancies prone to develop twin-twin transfusion syndrome.

New case of Beemer-Langer syndrome

We present the case of a male infant born at 37 weeks gestation with multiple congenital anomalies, including hydrops fetalis, facial and visceral abnormalities, short ribs, and short limbs without polydactyly. We believe that this represents a further case of the Beemer-Langer syndrome, a relatively recently described form of lethal osteochondrodysplasia with an autosomal recessive mode of inheritance. This case also showed some less frequently described anomalies, including arachnoid cysts of the brain and short intestines.