Fetal thymus volume estimation by virtual organ computer-aided analysis in normal pregnancies.

OBJECTIVES: The thymus has a pyramidal shape, which is best shown in coronal planes. The aim of this study was to evaluate the potential of virtual organ computer-aided analysis to estimate fetal thymus volume in normal pregnancies. METHODS: Three-dimensional volume data sets from the axial upper mediastinal section were acquired from 37 normal pregnancies between 12 and 35 weeks' gestation. Thymus volume was calculated by virtual organ computer-aided analysis by 2 separate examiners. In 12 cases, volumes were also acquired with 4-dimensional sonography and spatiotemporal image correlation software to assess the variability in thymus size between the systolic and diastolic periods of fetal heart motion. Linear regression analysis was used to assess the relationship between the fetal thymus volume and gestational age. Paired Student t tests were used to evaluate both the level of agreement for interobserver and intraobserver variability and the difference between diastolic and systolic thymus volumes. RESULTS: Identification of the borders of the thymus and calculation of its volume were successful in 28 patients (77.7%). Statistically significant linear growth of the thymus during pregnancy, from 12 to 35 weeks, was found. The growth coefficient for each gestational age was 0.43 (95% confidence interval, 0.355 to 0.504; P < .001). The difference in thymus size between systole and diastole was minor (0.0798 cm(3); 95% confidence interval, -0.044 to 0.203 cm(3)). Interobserver and intraobserver variability was not statistically significant. CONCLUSIONS: Although the thymus has a complex shape, it was possible to determine its borders and to calculate its volume by virtual organ computer-aided analysis in 77.7% of cases. Linear growth during pregnancy was found, and the minor changes during systole and diastole could be explained by condensation of the soft tissue of the thymus secondary to cardiac activity.

Prenatal diagnosis and follow-up of a case of branchio-oto-renal syndrome displays renal growth impairment after the second trimester.

Branchio-oto-renal syndrome combines branchial arch defects, hearing impairment and renal malformations or hypoplasia. Due to the high phenotypic variability, prenatal diagnosis has a limited prognostic value in mutation-positive cases. We report the first branchio-oto-renal syndrome molecular prenatal diagnosis and ultrasonographic follow-up, showing a normal renal growth until the 24th week of pregnancy, a growth deceleration during the third trimester and a renal volume recovery during the first months of life.

Early visualization and measurement of the pericallosal artery: an indirect sign of corpus callosum development.

OBJECTIVES: The purpose of this study was to evaluate the feasibility of visualization and measurement of the pericallosal artery during early stages of gestation. METHODS: The study group comprised 80 pregnant women between 12 and 21 weeks' gestation who attended our ultrasound unit. Transabdominal or transvaginal sonography was performed to obtain the optimal angle of a midsagittal section. High-definition flow power Doppler imaging was used to visualize the pericallosal artery. In a sagittal plane, the lengths of the pericallosal artery were measured using a straight line to connect the most anterior and posterior points. All patients were reexamined at a later stage of pregnancy to verify the existence of the corpus callosum and pericallosal artery. RESULTS: Visualization of the pericallosal artery was evident in 71 fetuses, in all of whom the biparietal diameter was greater than 20 mm. We were able to verify normal anatomy and the existence of the pericallosal artery in these fetuses between 30 and 32 weeks' gestation. A positive linear association was found between the length of the pericallosal artery and the gestational age (R(2) = 0.95) and the biparietal diameter at each gestational age (R(2) = 0.99). CONCLUSIONS: Our data show that it is feasible to visualize and measure the pericallosal artery from an early stage of gestation, and this measurement could be an indirect indication of normal corpus callosum development.

Vermian biometric parameters in the normal and abnormal fetal posterior fossa: three-dimensional sonographic study.

OBJECTIVES: The purposes of this study were to describe a 3-dimensional sonographic technique for evaluation of the fetal vermis and to compare vermian biometric parameters in fetuses with a normal and an abnormal posterior fossa. METHODS: A prospective study was conducted from 2006 through 2008 on 12 fetuses with an abnormal posterior fossa and 73 healthy control fetuses from 18 to 35 weeks' gestation. Three-dimensional scans of the fetal head were performed in the axial plane, using static volume contrast imaging in the C-plane. The vermian perimeter, cross-sectional area, and superoinferior diameter were measured and compared between abnormal and normal fetuses using the Wilcoxon nonparametric test. Linear regression analysis was used to describe trends of the vermis during gestation. The z scores for perimeter, cross-sectional area, and superoinferior diameter measurements in the abnormal posterior fossa group in each 2-week interval were calculated. RESULTS: Twelve fetuses with an abnormal posterior fossa were recruited: 3 with a Blake pouch cyst, 1 vermian cyst, 1 enlarged cisterna magna, 2 Dandy-Walker malformation, 4 partial vermian agenesis, and 1 hemicerebellar hypoplasia. The vermian cross-sectional area was reduced significantly in the fetuses with an abnormal posterior fossa compared with the control fetuses starting at 18 to 19 weeks' gestation (P = .01); the mean vermian superoinferior diameter was lower only from 22 to 23 weeks (P = .01); and the mean vermian perimeter was decreased from 28-29 weeks' gestation (P = .03). Linear regression analysis of the parameters showed that fetuses with an abnormal posterior fossa had a statistically significantly lower growth rate than control fetuses during gestation (P < .001). CONCLUSIONS: Measurements of the cross-sectional area were more useful than those of the perimeter and superoinferior diameter in distinguishing between fetuses with a normal and an abnormal posterior fossa during the early stages of gestation.

Prenatal diagnosis and postnatal follow-up of a child with mosaic trisomy 22 with several levels of mosaicism in different tissues.

We report on the case of a patient with mosaic trisomy 22, who was diagnosed prenatally by amniocentesis during the 16(th) week of pregnancy. In the foetus, three trisomic clones were found out of the nine that were analyzed (the other six clones had a 46,XY karyotype). Cytogenetic analysis of cord blood during the 20(th) week of pregnancy showed a normal male karyotype; however, a placental biopsy that was performed at the same time showed 100% and 95% trisomic cells in the chromosomal analysis of direct and long-term cultures, respectively. A follow-up ultrasonographic examination excluded major congenital malformations and the abdominal and cranial circumferences were normal until the 24(th) week of pregnancy. At this point, a deflection of the growth curve occurred and the values were persistently below the 3(rd) centile until birth. After birth, karyotypic and fluorescent in situ hybridisation analyses performed on the fibroblasts of the neonate showed that 3-4% of the cell lines were trisomic, and studies using microsatellite markers showed normal allelic segregation, which excluded uniparental disomy. The period of postnatal follow-up was characterised by a significant growth deficit (height and head circumference were less than the 3(rd) centile) and by mental retardation. The present case is compatible with other earlier reports that showed that the levels of trisomy 22 are tissue-specific and are of little help in establishing the prognosis of the chromosomal abnormality.

Sexual dimorphism in the levels of amniotic fluid leptin in pregnancies at 16 weeks of gestation: relation to fetal growth.

OBJECTIVE: To investigate whether in the first half of pregnancy levels of leptin in amniotic fluid are sexually dimorphic, and are related to fetal growth. STUDY DESIGN: Samples of amniotic fluid were collected during amniocentesis from 211 pregnancies with a single fetus with a normal karyotype (107 from male fetuses). Fetal growth was evaluated at 16 and 32 weeks of gestation, by sonography, and in a subset of 137 women at delivery. RESULTS: Amniotic fluid leptin was significantly lower in male than female fetuses (7.91+/-0.36 ng/ml versus 10.45+/-0.38 ng/ml; p = 0.0001). In females, levels of leptin were inversely related to BPD measured at 16 weeks (r = -0.241; p = 0.013) to biparietal diameter (BPD) (r = -0.281; p = 0.0076) and abdominal circumference (r = 0.268; p = 0.0107) measured at 32 weeks of gestation and to neonatal weight (r = -0.236; p = 0.051), neonatal weight/height (r = -0.271; p = 0.026) or neonatal Kaup index (r = 0.255; p = 0.045). Leptin was not related to any fetal parameter in males. CONCLUSIONS: Levels of leptin in amniotic fluid at 16 weeks of gestation are sexually dimorphic and are inversely related to fetal growth, particularly of females.

Pre- and post-natal growth in two sisters with 3-M syndrome.

3-M syndrome (OMIM #273750) is a rare autosomal recessive growth disorder characterized by severe pre- and post-natal growth restriction, associated with minor skeletal abnormalities and dysmorphisms. Although the 3-M syndrome is well known as a primordial dwarfism, descriptions of the prenatal growth are missing. We report a family with variable phenotypic features of 3-M syndrome and we describe the prenatal and postnatal growth pattern of two affected sisters with a novel homozygous CUL7 mutation (c.3173-1G>C), showing a pre- and post-natal growth deficiency and a normal cranial circumference.

Induction of labor in women with oligohydramnios.

OBJECTIVE: To prospectively evaluate the outcome of labor induction in women with oligohydramnios at term. METHODS: This was a prospective case-control study which included 120 consecutive patients with Amniotic Fluid Index (AFI) < or =5 undergoing labor induction. One hundred and sixteen patients with normal amniotic fluid matched for gestational age (+/- 3 days) and Bishop-score served as controls. Inclusion criteria were: requirement of labor induction, singleton pregnancy, nulliparity, Bishop score <5, gestational age > or =266. Preinduction treatment included the use of up to 3 successive doses of dinoprostone intracervical gel (0.5 mg). Vaginal dinoprostone (2 mg) and/or oxytocin were then applied to induction labor, if necessary. RESULTS: The rate of cesarean section in AFI < or = 5 group (38.3%) was not significantly different to that in control group (34.2%). The interval from induction to vaginal delivery was not significantly different for AFI < or =5 group (1499 +/- 895 min.) and control group (1398 +/- 852 min.). The changes in Bishop score evaluated at 6th and 12th hour after dinoprostone were not significantly different in control and AFI< or =5 group. More women in the latter group (11.7% vs 3.3%, Chi Square:4.86, p = 0.027) required the use of drugs in order to manage tachysystole/hyperstimulation allowing a OR = 3.83 (95%C.I. = 1.13-14.27). The length of stay at hospital was 4.2 +/- 1.8 days for AFI < or =5 group and 4.3 +/- 1.3 for control group. CONCLUSIONS: Oligohydranmios at term did not influence the outcome of induction of labour in nulliparous women with unfavorable cervix.

Surface rendering of external genitalia of a fetus at the 32nd week of gestation affected by partial androgen insensitivity syndrome.

Objectives. To demonstrate the feasibility of the prenatal diagnosis of partial androgen insensitivity syndrome by 3D-4D ultrasound. Methods. To report prenatal diagnosis of partial androgen insensitivity syndrome at 32nd week of gestation by 3D-4D ultrasound in a fetus with a 46XY karyotype, testing negative to the mutation analysis of SRY gene and the 5 α -reductase 2 gene (SRD5A2). Results. 3D-4D surface rendering allows the detection of external and internal genital malformations and can address the prenatal diagnosis of PAIS and can exclude associated complications. Conclusions. Prenatal diagnosis of PAIS allows an adequate parental counseling and an early optimal management of the condition, not only for the psychological and social reflections but also for the avoidance of complications and postnatal morbidity due to misdiagnosis or delays in the treatment of the genital ambiguity.

Second trimester amniocentesis is not a risk factor for very low birth weight and extremely low birth weight.

Objectives. To assess the risk of very low birth weight (VLBW) and extremely low birth weight (ELBW) attributable to second trimester amniocentesis. Methods. Records of 4,877 consecutive amniocentesis, performed between 1997 and 2003, were analyzed. Only VLBW and ELBW in the study population (exposed) and in the control group (unexposed) were evaluated. Comparisons were made between the amniocentesis group versus nonexposed. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated for VLBW and ELBW classes. Results. In the study population, the VLBW were 35 (0.71%) and the ELBW were 20 (0.41%). In the control group, the VLBW were 220 (0.67%) and the ELBW were 112 (0.34%). The Odds ratios of the VLBW between the study and the control group did not show any statistical significant risk (OR = 1.07, 95% CI = 0.72-1.54). Also in ELBW odds ratios between study and control group were not statistically significant (OR = 1.20, 95% CI = 0.7-1.95). Conclusions. No effect of the second trimester amniocentesis was noted on VLBW and ELBW.

Age-specific risk of fetal loss post second trimester amniocentesis: analysis of 5043 cases.

OBJECTIVES: To assess the risk of fetal loss attributable to second trimester amniocentesis in singleton pregnancies through a cross-sectional study. METHODS: Records of 5043 consecutive second trimester amniocentesis, performed by a single operator between 1997 and 2003, were analyzed. Fetal loss post amniocentesis was calculated by grouping pregnant women in age classes and assessing observed/expected (O/E) rate. RESULTS: Total fetal losses were 40 (0.81%): 33 cases (0.67%) occurred before the 24th week, 37 cases (0.76%) before the 28th gestational week, and 3 cases (0.06%) after the 28th week of pregnancy. An age-dependent increase of the rate of fetal loss, not statistically significant (Chi-Square = 0.349, p = 0.505) was observed. The total O/E ratio values did not show any statistically significant risk (O/E ratio = 1.25, CI = 0.86-1.64). The analysis of the single age classes did not detect any statistical significance. The excess fetal loss rate associated with amniocentesis was 0.16%. CONCLUSIONS: No effect of the 2nd trimester amniocentesis was noted on fetal loss.