Semi-automated system for measurement of nuchal translucency thickness.

OBJECTIVE: To estimate intersonographer and intrasonographer variance components of fetal nuchal translucency (NT) thickness measurement using the traditional manual approach and a new semi-automated system. METHODS: A semi-automated method was developed for measurement of the NT. In this method, the operator places an adjustable box over the relevant area at the back of the fetal neck. The system draws a line through the center of the nuchal membrane and another line at the edge of the soft tissue overlying the cervical spine. The system then identifies the largest vertical distance between the two lines. The images of 12 fetuses at 11-13 weeks of gestation satisfying the guidelines of The Fetal Medicine Foundation for measurement of NT were selected. They were exported in DICOM format from the ultrasound system, and four versions of each image were stored under different names. The resulting 48 images were presented in random order for electronic assessment. A total of 20 sonographers measured the NT in each set of 48 pictures, twice using the semi-automated system and twice using the manual system, according to a randomized block design. Within- and between-operator variance components were estimated. Relative biases were assessed by comparing the means from the two methods. RESULTS: The estimated between-operator SD using the semi-automated method was 0.0149 mm compared with 0.109 mm for the manual method. The respective within-operator SD values were 0.05 mm and 0.126 mm. The intraclass correlation coefficients for different sonographers measuring the same images were 0.98 and 0.85 for the semi-automated method and the manual method, respectively. CONCLUSION: The measurement of fetal NT is more reliable when a semi-automatic approach is used rather than the traditional manual method.

Aberrant right subclavian artery at 16 to 23 + 6 weeks of gestation: a marker for chromosomal abnormality.

OBJECTIVES: This study was carried out to determine the feasibility of defining the position of the right subclavian artery (RSA) by fetal echocardiography between 16 and 23 weeks of gestation, and the association between an aberrant right subclavian artery (ARSA) and chromosomal and cardiac defects. METHODS: We examined the position of the RSA in all patients who attended our unit for a fetal cardiac scan. The assessment was carried out using a transverse view of the fetal chest sweeping up from the level of the aortic arch, using color flow mapping. An ARSA was diagnosed when this vessel was not seen in the normal position and an arterial vessel was seen crossing behind the trachea towards the right arm, arising as a fourth branch of the aortic arch, at a lower level than normal. RESULTS: The course of the RSA could be identified in more than 95% of the 2799 fetuses examined between 16 and 23 + 6 weeks of gestation. An ARSA was found in 43 fetuses. The incidence was 1.5% in normal fetuses, 28.6% in fetuses with trisomy 21, 18.2% in fetuses with trisomy 18 and 8% in fetuses with other chromosomal defects. There was an association between an ARSA and cardiac defects in seven of the 43 fetuses (16%), and three of these seven fetuses had a normal karyotype. CONCLUSIONS: Assessment of the RSA by a fetal cardiologist is possible in almost all cases. The finding of an ARSA is much more common in fetuses with chromosomal defects, in particular trisomy 21 (where the prevalence of an ARSA was 29%), compared with euploid fetuses. Moreover, the presence of an ARSA may be associated with an increased incidence of intracardiac malformations. Examination of the position of the RSA is likely to become a routine ultrasound marker for chromosomal abnormalities in the second trimester of pregnancy.

Effect of temperature on free beta-human chorionic gonadotropin and pregnancy-associated plasma protein-A concentration.

OBJECTIVE: To examine the effect of the duration of storage of serum and whole blood at different controlled temperatures on the concentrations of both serum free-beta-human chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A) in first-trimester screening for aneuploidies. METHODS: The concentrations of free beta-hCG and PAPP-A were measured in samples collected from 10 pregnant women and stored as whole blood or serum for 1-8 days at 4, 20 or 40 degrees C. The concentrations measured were adjusted to take day-to-day variations into account and were expressed as a percentage of the values on day 0. In a second study involving 10 pregnant women, free beta-hCG was measured at 10 min and at 2, 4, 8 and 12 h after collection and storage at 30 or 40 degrees C, either as separated serum or as whole blood. RESULTS: The change in the levels of PAPP-A in the separated serum at all three temperatures and in whole blood at 4 degrees C was always less than 10% throughout the 8 days of storage. In whole blood stored at 20 and 40 degrees C, the percentage variation was less than 10% only if the storage period was shorter than 4 days. The concentration of free beta-hCG was not altered by storage of either whole blood or separated serum at 4 degrees C throughout the 8 days of storage. At 20 degrees C, reliable results were obtained only if the maximum storage time was 2 days for separated serum and 1 day for whole blood. At 30 degrees C, reliable results were obtained only if the samples were analyzed within 2 h of collection, and at 40 degrees C the concentrations increased by more than 50% within 2 h and by about 500% after 1 day of storage. CONCLUSION: In first-trimester screening for aneuploidies, analysis of blood samples should be undertaken within a few minutes of collection, otherwise the samples should be refrigerated at 4 degrees C throughout the interval between collection and analysis.

Involvement of Sp-1 in the regulation of the Id-1 gene during trophoblast cell differentiation.

Id-1, a member of the helix-loop-helix transcription factor family, inhibits the differentiation of Rcho-1 cells, which were derived from rat choriocarcinoma and consist of trophoblast stem cells. Id-1 is expressed at a high level in undifferentiated trophoblast stem cells and then down-regulated during early differentiation, and is thought to be a key regulator in the trophoblast giant-cell differentiation pathway. In this study, we analyzed the signaling mechanism regulating the high expression levels of Id-1 in undifferentiated Rcho-1 cells. Promoter deletion analysis revealed that a 31-bp sequence (Box-2 region), located between -200 and -169bp in the Id-1 promoter is necessary for the promoter activity. Electrophoretic mobility shift assays and DNA affinity precipitation assays showed that Box-2-binding activity was decreased during differentiation and that Sp-1 protein bound to this sequence. The protein level of Sp-1 was decreased during the differentiation. These results suggest that the Sp-1 protein level may regulate the Box-2-binding activity and the trophoblast giant-cell differentiation.

STAT3-mediated constitutive expression of SOCS3 in an undifferentiated rat trophoblast-like cell line.

In the trophoblast, constitutive expression of SOCS3 is important for the negative regulation of trophoblast giant cell differentiation. In this study, we analyzed the signaling pathway regulating the constitutive SOCS3 expression in undifferentiated Rcho-1 cells, which were derived from rat choriocarcinoma and consist of trophoblast stem cells that are capable of differentiating to trophoblast giant cells in vitro. PD98059, an MEK inhibitor, repressed the SOCS3 expression but AG490, a JAK2 inhibitor, did not. Promoter deletion analysis revealed that the STAT response element (SRE) in the SOCS3 promoter is necessary for the promoter activity. Overexpression of STAT3 increased the SOCS3 promoter activity, whereas expression of dominant-negative STAT3 reduced it. Constitutive STAT3 tyrosine phosphorylation that was not inhibited by either AG490 or PD98059 was demonstrated. Electrophoretic mobility shift assays showed the existence of a protein that bound to SRE and was supershifted with STAT3 antibody. This binding reaction was inhibited by neither AG490 nor PD98059. These findings imply that the ERK/MAPK pathway and STAT3 are involved in the constitutive activation of SOCS3 in undifferentiated Rcho-1 cells. Moreover, they indicate that the constitutive STAT3 tyrosine phosphorylation and the DNA binding activity of STAT3 do not depend on the ERK/MAPK or JAK kinase pathway. These results suggest that a trophoblast-specific STAT3 activation pathway is important for the regulation of giant cell differentiation.

Antenatal diagnosis and treatment of a case of fetal goitrous hypothyroidism associated with high-output cardiac failure.

A case of fetal goitrous hypothyroidism associated with high-output cardiac failure is presented. At 32 weeks of gestation, the antenatal diagnosis of goiter was made based on ultrasound examination, and the fetal thyroid function was examined by amniocentesis and cordocentesis. Color and pulsed Doppler examinations demonstrated a high vascular flow pattern in the goiter and marked elevation of the maximum velocity in the common carotid artery at the level of the neck. It was suspected that arteriovenous shunting through the large goiter resulted in high-output cardiac failure with cardiomegaly and pleural effusion. The fetus was treated by injection of levothyroxine sodium into the amniotic fluid at 33 weeks of gestation and the goiter thereafter decreased in size, with subsequent improvement of the high-output cardiac failure. The maximum velocity in the common carotid artery fell rapidly before the shrinkage of the fetal goiter and in parallel with the fetal level of thyroid stimulating hormone.