Reference charts of fetal biometric parameters in 31,476 Brazilian singleton pregnancies.

OBJECTIVES: The purpose of this study was to establish reference charts of fetal biometric parameters measured by 2-dimensional sonography in a large Brazilian population. METHODS: A cross-sectional retrospective study was conducted including 31,476 low-risk singleton pregnancies between 18 and 38 weeks' gestation. The following fetal parameters were measured: biparietal diameter, head circumference, abdominal circumference, femur length, and estimated fetal weight. To assess the correlation between the fetal biometric parameters and gestational age, polynomial regression models were created, with adjustments made by the determination coefficient (R(2)). RESULTS: The means ± SDs of the biparietal diameter, head circumference, abdominal circumference, femur length, and estimated fetal weight measurements at 18 and 38 weeks were 4.2 ± 2.34 and 9.1 ± 4.0 cm, 15.3 ± 7.56 and 32.3 ± 11.75 cm, 13.3 ± 10.42 and 33.4 ± 20.06 cm, 2.8 ± 2.17 and 7.2 ± 3.58 cm, and 256.34 ± 34.03 and 3169.55 ± 416.93 g, respectively. Strong correlations were observed between all fetal biometric parameters and gestational age, best represented by second-degree equations, with R(2) values of 0.95, 0.96, 0.95, 0.95, and 0.95 for biparietal diameter, head circumference, abdominal circumference, femur length, and estimated fetal weight. CONCLUSIONS: Fetal biometric parameters were determined for a large Brazilian population, and they may serve as reference values in cases with a high risk of intrauterine growth disorders.

Reference values of nuchal translucency thickness in a Brazilian population sample: experience from a single center.

OBJECTIVE: To determine the reference values of nuchal translucency (NT) thickness at 11-14 weeks of gestation in a sample of the Brazilian population. METHODS: A retrospective cross-sectional study was carried out with singleton gestations and fetuses with a crown-rump length (CRL) of 45-84 mm. NT thickness was performed according to the guidelines of the Fetal Medicine Foundation (FMF), London, UK. To evaluate the correlation between NT thickness and gestational age (GA), polynomial equations were calculated, with determination coefficient (R2) adjustments, as proposed by Altman-Chitty. RESULTS: A total of 1420 pregnancies were assessed. The mean of the gestational age was 12.69±0.78 weeks. The mean maternal age was 28.78±6.81 years. The mean NT thickness (mm) for the CRL intervals of 45├50; 50├55; 55├60; 60├65; 65├70; 70├75; 75├80; 80├85 was 1.30±0.74; 1.34±0.60; 1.48±0.48; 1.56±0.68; 1.71±0.67; 1.78±0.69; 1.67±0.43; 1.67±0.58; respectively. The following second-order equation best represented the correlation between NT thickness and GA: NT=-1.2570+0.0765×GA-0.0005×GA2 (R2=0.05). CONCLUSION: The reference values for NT thickness were determined for a sample of the Brazilian population. Further studies are required to evaluate the real need for including these values in first-trimester screening for chromosomal defects in Brazil.

Reference range for amniotic fluid index measurements in a Brazilian population.

OBJECTIVE: The aim of this study was to determine the reference range for amniotic fluid index (AFI) measurements in a large sample of the Brazilian population. METHODS: This was a retrospective cross-sectional study on 3837 normal singleton pregnancies between 18+0 and 38+6 weeks of pregnancy. The AFI was measured from the largest vertical pockets of amniotic fluid in the four quadrants of the uterine cavity. To assess the correlation between AFI and gestational age (GA), polynomial equations were calculated, with adjustments using the determination coefficient (R2). RESULTS: The mean maternal age and gestational age were 27.01±6.57 years and 30.43±5.29 weeks, respectively. The mean AFI ranged from 12.2±2.6 cm at 18 weeks to 11.6±6.0 cm at 38 weeks of pregnancy. The correlation between AFI and GA was best represented by a linear equation: AFI=17.78-0.153*GA (R2=0.027). CONCLUSION: We established the reference range for the AFI in a large sample of the Brazilian population. This reference range can be used to monitor deviations in the volume of amniotic fluid in fetuses at high risk for intrauterine growth disturbances.

[Prenatal ultrasound diagnosis of adrenal neuroblastoma]. / Diagnóstico prenatal ultrasonográfico de neuroblastoma adrenal.

Neuroblastoma is the most frequent solid malignant tumor in the neonatal period; however, its diagnosis is very difficult in the prenatal one. This kind of tumor has a high morbidity and mortality rate due to the metastatic risk. Its prognosis depends on the affected area, on the extension of the tumor, and on the associated abnormalities. The antenatal ultrasound diagnosis is possible by finding a mixed mass in the adrenal gland. We report a case of a bilateral adrenal neuroblastoma diagnosed by antenatal ultrasonography at the 29th week of gestation. We describe the principal findings and show the contribution of the tridimensional ultrasound on the relationship of the tumor with the nearby structures.

Reference range of fetal transverse cerebellar diameter between 18 and 24 weeks of pregnancy in a Brazilian population.

To determine a reference range of fetal transverse cerebellar diameter in Brazilian population. This was a retrospective cross-sectional study with 3772 normal singleton pregnancies between 18 and 24 weeks of pregnancy. The transverse cerebellar diameter was measured on the axial plane of the fetal head at the level of the lateral ventricles, including the thalamus, cavum septum pellucidum, and third ventricle. To assess the correlation between transverse cerebellar diameter and gestational age, polynomial equations were calculated, with adjustments by the determination coefficient (R2). The mean of fetal transverse cerebellar diameter ranged from 18.49 ± 1.24 mm at 18 weeks to 25.86 ± 1.66 mm at 24 weeks of pregnancy. We observed a good correlation between transverse cerebellar diameter and gestational age, which was best represented by a linear equation: transverse cerebellar diameter: -6.21 + 1.307*gestational age (R2 = 0.707). We determined a reference range of fetal transverse cerebellar diameter for the second trimester of pregnancy in Brazilian population.

Prenatal diagnosis of the 13q-syndrome through three-dimensional ultrasonography: a case report.

CONTEXT: The deletion of the short arm of the chromosome 13, also known as 13q syndrome, is an extremely rare chromosomal disorder. Clinical manifestations include retinoblastoma, brain anomalies, mental and growth retardation, as well as renal, cardiac, gastrointestinal, facial, lip and digital defects. Antenatal diagnosis is suspected when the presence of anomalies is detected and it is confirmed through chromosome analysis. CASE REPORT: We reported a case of the 13q syndrome which was diagnosed in the 23rd week of gestation in a fetus with holoprosencephaly and we discussed the two and three-dimensional ultrasonography main findings. This is the first case reported in MEDLINE involving the use of three-dimensional ultrasonography in the structural anomalies evaluation of this syndrome.