Effects of antenatal corticosteroids on fetal hemodynamics: a longitudinal study.

Objective: To study the effect of antenatal corticosteroid administration on fetal hemodynamics using longitudinal analysis of Doppler waveforms in the umbilical artery (UA) and middle cerebral artery (MCA). Materials and Methods: This was a retrospective study that included 30 fetuses at risk for preterm birth. Twenty-eight pregnant women were treated with betamethasone for fetal lung maturation. Doppler examinations of the UA and MCA were performed once before and three or eight times after corticosteroid administration. We used a Bayesian hierarchical linear model. Reference ranges were constructed, and associations between variables (gestational age and pre-eclampsia) were tested. Results: The mean maternal age, gestational age at betamethasone administration, and gestational age at delivery were 32.6 ± 5.89 years, 30.2 ± 2.59 weeks, and 32.9 ± 3.42 weeks, respectively. On UA Doppler, there was a significant decrease in the pulsatility index (PI) after corticosteroid administration, with a mean of 0.1147 (credibility interval: 0.03687-0.191) in three observations and a median of 0.1437 (credibility interval: 0.02509-0.2627) in eight observations. However, there was no significant change in the Doppler MCA PI, regardless of gestational age and the presence or absence of pre-eclampsia. Conclusion: Although antenatal corticosteroid administration induced a significant decrease in the Doppler UA PI, we observed no change in the cerebral vasculature.

Objetivo: Estudar o efeito da administração antenatal de corticosteroides na hemodinâmica fetal mediante análise longitudinal do Doppler na artéria umbilical (AU) e artéria cerebral média (ACM). Materiais e Métodos: Este foi um estudo retrospectivo que incluiu 30 fetos com risco de nascimento pré-termo. Vinte e oito gestantes foram tratadas com betametasona para maturação pulmonar fetal. Os exames de Doppler da AU e da ACM foram realizados uma vez antes e depois da administração de corticosteroides, num total de três ou oito observações. Utilizamos o modelo linear hierárquico com abordagem Bayesiana. Foram construídos os intervalos de referência e testadas associações entre variáveis (idade gestacional e pré-eclâmpsia). Resultados: A média ± desvio-padrão da idade materna, idade gestacional na administração de betametasona e idade gestacional no parto foram 32,6 ± 5,89 anos, 30,2 ± 2,59 semanas e 32,9 ± 3,42 semanas, respectivamente. No Doppler da AU, verificou-se diminuição significativa do índice de pulsatilidade (IP) com a terapêutica com corticosteroides (média: 0,1147 [0,03687-0,191]; em três observações) (mediana: 0,1437 [0,02509-0,2627]; em oito observações). No entanto, não foi observada alteração significativa no IP do Doppler da ACM, independentemente da idade gestacional e do diagnóstico de pré-eclâmpsia. Conclusão: Os corticosteroides pré-natais induziram diminuição significativa no IP do Doppler da AU, mas não houve alteração na vasculatura cerebral.

Cervical length measurement between 11 and 13 + 6 weeks of pregnancy: Comparison of maternal and ultrasonographic characteristics between term and preterm deliveries.

OBJECTIVE: The aim of this study was to evaluate the maternal and ultrasonographic characteristics of pregnant women who underwent cervical length (CL) measurement by transvaginal ultrasound between 11 and 13 + 6 weeks of gestation and who delivered at term or preterm. METHODS: A retrospective cohort study was carried out between March 2013 and December 2018 by analyzing ultrasound data of singleton pregnant women who underwent CL measurement by transvaginal ultrasound during the first trimester scan. CL was compared between the two groups (full-term and preterm birth [PB]) using Student's t-test. RESULTS: A total of 5097 pregnant women were enrolled, of whom 5061 (99.3%) had term and 36 (0.7%) had PB < 34 weeks. CL measurements did not differ between the term and preterm groups (36.62 vs. 37.83 mm, p = 0.08). Maternal age showed a significant and linear association with CL (r = 0.034, p = 0.012) and CRL (r = 0.086, p < 0.001). Smoking status was associated with shorter CL (36.64 vs. 35.09 mm, p = 0.003). When we analyzed the CL of the pregnant women in the term and preterm groups, according to the gestational age cut-offs for prematurity (28, 30, 32, and 34 weeks), we found that there was no significant difference between the measurements in all groups (p > 0.05). CONCLUSION: We observed no significant differences between CL measurements between 11 and 13 + 6 weeks in pregnant women who had preterm and term deliveries. Gestational age and CRL showed a significant and linear association with CL measurement.

Fetal hemodynamics and placental histopathology in Down syndrome.

OBJECTIVE: To evaluate the association between Doppler patterns in fetuses with Down syndrome (DS) and their placental histopathologic findings. METHODS: A retrospective cross-sectional study was performed by collecting data from medical records of singleton pregnancies between January 2014 and January 2022, whose fetuses had a confirmed diagnosis of DS either prenatally or postnatally. Placental histopathology, maternal characteristics, and prenatal ultrasound (biometric parameters and umbilical artery [UA] Doppler) were evaluated. RESULTS: Of 69 eligible pregnant women, 61 met the inclusion and exclusion criteria. In the sample, 15 fetuses had an estimated fetal weight < 10th percentile for gestational age (GA) and were considered small for gestational age (SGA). Thirty-eight fetuses had increased resistance on the UA Doppler. Histologic changes were detected in 100% of the placentas, the most common being delayed villous maturation, alterations associated with poor fetal vascular perfusion, and villous dysmorphism. More than 50% of the placentas showed alterations related to placental insufficiency. We did not observe a statistically significant association between UA Doppler examination and placental alterations. All placentas analyzed in the SGA subgroup showed findings compatible with placental insufficiency. CONCLUSION: We found no statistically significant association between placental histopathologic findings and UA Doppler abnormalities in fetuses with DS. The placental alterations identified were delayed villous maturation, alterations associated with poor fetal vascular perfusion, and villous dysmorphism.

Comparing Two- and Three-dimensional Antral Follicle Count in Patients with Endometriosis.

Background: The purpose of the study was to compare three-dimensional (3D) ultrasound semiautomatic antral follicle count (AFC) with two-dimensional (2D) ultrasound real-time AFC to evaluate patients with deep endometriosis and/or endometrioma submitted to ovarian stimulation (OS). Methods: This was a retrospective cohort study assessing all women with documented diagnosis of deep endometriosis who underwent OS for assisted reproduction treatment. The primary outcome was the difference between AFC by semiautomatic 3D follicle count using 3D volume datasets and 2D ultrasound count with the number of oocytes retrieved at the end of the cycle. The 3D ultrasound AFC was obtained using sonography-based automated volume count (SonoAVC), and the 2D ultrasound AFC data was collected from the electronic medical record. Results: Total of 36 women had deep endometriosis documented by magnetic resonance imaging, laparoscopy, or ultrasonography and 3D ovarian volume datasets stored from their first exam. The differences between the 2D and 3D AFC and the number of oocytes retrieved at the end of the stimulation were compared, showing no significant statistical difference between both methods (P = 0.59). Correlations were similar using both methods when compared to the number of oocytes retrieved (2D [r = 0.83, confidence interval (CI) = 0.68-0.9, P < 0.001]); (3D [r = 0.81, CI = 0.46-0.83, P < 0.001]). Conclusion: 3D semiautomatic AFC can be used to access the ovarian reserve in patients with endometriosis.

Assessment of Fetal Lung Maturity Using Quantitative Ultrasound Analysis in Patients with Prelabor Rupture of Membranes.

INTRODUCTION: Prelabor rupture of membranes (PROM) is a frequent clinical situation, and the decision about the best time for delivery remains controversial, mainly due to the risk of neonatal respiratory morbidity (NRM). Assessment of fetal lung maturity using ultrasound, a safe method and widely used in current obstetrical practice, could change this scenario. This study was designed to evaluate the ability of quantitative ultrasound method QuantusFLM® to predict NRM in patients with PROM and whether maternal BMI, gestational age, occurrence of the disease, and presence of oligohydramnios influenced the performance. METHODS: Patients with singleton gestations, diagnosis of PROM, and gestational age between 24 and 38 weeks and 6 days were included. Fetal lung image was acquired by ultrasound within 48 h prior to delivery and analyzed by QuantusFLM®. The results were then paired with neonatal outcomes to assess the program's ability to predict the NRM in this specific group. A logistic regression model was created to analyze factors that could affect the test results. RESULTS: Fifty-four patients were included. Mean maternal BMI was 28.99 kg/m2, and in 25 patients (46.2%), oligohydramnios was observed at the time of examination. Mean gestational age at delivery was 35 weeks and 4 days, and the NRM prevalence was of 18.5%. QuantusFLM® predicted NRM with a 60% sensitivity, 79.5% specificity, 40% positive predictive value, 89.7% negative predictive value, and 75.6% accuracy. Maternal BMI, disease occurrence, presence of oligohydramnios, and gestational age did not interfere with the evaluation. CONCLUSION: This study demonstrates a good accuracy of QuantusFLM® as a NRM predictor in patients with PROM, with particular reliability in identifying that pulmonary maturity has already occurred.

Fetal ultrasound estimated weight and correlation to Brazilian newborn weight.

Background: To compare the best fetal weight formula with different biometric tables on the weight of Brazilian newborns. Methods: This observational study has tested the performance of different common fetal weight formulas and biometric tables. Weight estimates were performed by the methods of Warsof et al. (1977), Shepard et al. (1982), Hadlock et al. (1985), Furlan et al. (2012) and Stirnemann et al. (2017). The biometric tables selected were the following: Snijders and Nicolaides (1994), Hadlock et al. (1984), Papageorghiou et al. (2014) and Kiserud et al. (2016) and correlated to Pedreira et al. (2011) database, which was considered the gold standard. Statistical analyses were performed using the mean relative error, average absolute error and the Pearson correlation coefficient (r). Results: The best r was found when using the Snijders and Nicolaides (1994) biometric table with weight formula by Stirnemann et al. (2017). The average relative error was lower when using weight formula by Shepard et al. (1982) with biometric tables by Snijders and Nicolaides (1994), Papageorghiou et al. (2014) or Kiserud et al. (2016). On average, absolute error, the lowest r was obtained for the Furlan et al. (2012) weight formula and the Papageorghiou et al. (2014) biometric table. Conclusions: The best correlation was found for biometric table by Snijders and Nicolaides (1994) and fetal weight formula calculation for the estimation of Brazilian newborn weight by Stirnemann et al. (2017).Background: To compare the best fetal weight formula with different biometric tables on the weight of Brazilian newborns. Methods: This observational study has tested the performance of different common fetal weight formulas and biometric tables. Weight estimates were performed by the methods of Warsof et al. (1977), Shepard et al. (1982), Hadlock et al. (1985), Furlan et al. (2012) and Stirnemann et al. (2017). The biometric tables selected were the following: Snijders and Nicolaides (1994), Hadlock et al. (1984), Papageorghiou et al. (2014) and Kiserud et al. (2016) and correlated to Pedreira et al. (2011) database, which was considered the gold standard. Statistical analyses were performed using the mean relative error, average absolute error and the Pearson correlation coefficient (r). Results: The best r was found when using the Snijders and Nicolaides (1994) biometric table with weight formula by Stirnemann et al. (2017). The average relative error was lower when using weight formula by Shepard et al. (1982) with biometric tables by Snijders and Nicolaides (1994), Papageorghiou et al. (2014) or Kiserud et al. (2016). On average, absolute error, the lowest r was obtained for the Furlan et al. (2012) weight formula and the Papageorghiou et al. (2014) biometric table. Conclusions: The best correlation was found for biometric table by Snijders and Nicolaides (1994) and fetal weight formula calculation for the estimation of Brazilian newborn weight by Stirnemann et al. (2017).

Behavior of fetal longitudinal myocardial fibers assessed by speckle tracking to obtain strain and strain rate values for low-risk pregnancies.

Objective To analyze the behavior of fetal longitudinal myocardial fibers assessed by speckle tracking (STE) after fetal viability. Methods A cross-sectional study was performed in 156 women with normal singleton pregnancies from 22 to 31 weeks of gestation. Strain (S) and strain rate (SR) values were measured in both ventricles during the fetal cardiac cycle. The population was divided into five gestational age groups based on 2-week intervals. The correlations of maternal variables with the S and SR variables and intra-observer analysis were performed. Results There was a significant difference in the S and SR values of the left ventricle (LV) among the gestational age groups (P = 0.007). Significantly higher S and SR values were observed in early age groups demonstrating reductions in LV S and SR values at 26 weeks, followed by stabilization. For the right ventricle (RV), there was no significant difference between gestational age groups. Significant intra-observer agreement was observed for S values of the RV (P = 0.008) and LV (P = 0.0004) and SR values of the RV (P = 0.0001) and LV (P = 0.015). Conclusion Decreases in the S and SR values of the LV occurred after 26 weeks, followed by stabilization. No significant difference was observed in the S or SR value of the RV among the gestational age groups, and no significant association of any maternal variable evaluated with S and SR values was observed. Significant intra-observer agreement was obtained among the results.

Predictors of perinatal outcome in early-onset fetal growth restriction: A study from an emerging economy country.

OBJECTIVE: To identify antenatal predictors of adverse perinatal outcomes in a population of preterm fetuses with early placental insufficiency diagnosed by Doppler abnormalities. METHOD: In this cross-sectional study of a cohort of singleton pregnant women diagnosed with early placental insufficiency, relationships between perinatal variables (arterial and venous Doppler, gestational age, birth weight, oligohydramnios, estimated fetal weight, and fetal weight z-scores) and major neonatal complications were analyzed by logistic regression. RESULTS: Two hundred sixty-five women were delivered, between 24 and 33 weeks gestation. The overall frequency of intact survival was 57.9% (n = 154). Gestational age thresholds for best prediction of survival was 27 + 6 weeks and for intact survival was 29 + 0 weeks gestation. Fetal weight and absent/reversed ductus venosus a-wave were the main predictors of survival in the regression model. When fetal weight was substituted for fetal weight z-score, ductus venosus abnormal Doppler predicted mortality and absent or reversed umbilical artery diastolic velocities predicted intact survival. CONCLUSIONS: This study illustrates the impact of gestational age and fetal weight on perinatal outcomes in early placental insufficiency, with well-defined thresholds. Gestational age and fetal weight, or a combination of fetal weight z-scores and fetal Doppler parameters, were the best predictors of intact survival in our sample.

3-D Virtual Reconstruction of a Large Amniocele With Protrusion of Legs and Umbilical Cord Following Asymptomatic Uterine Rupture.

BACKGROUND: Complete uterine rupture is a rare and severe intrapartum complication with high rates of maternal and fetal mortality. Asymptomatic uterine rupture is a very rare condition with one unique previous case described in the literature. Three-dimensional virtual models allow an immersive virtual reality of maternal-fetal structures with better understanding by the parents and the medical team. CASE: We demonstrate a case of asymptomatic rupture uterine with a large amniocele and protruded legs and umbilical cord at 28 weeks of gestation by using a 3-D virtual model from ultrasound scan data. CONCLUSION: 3-D virtual models may be applied to the assessment of obstetric complications, thereby allowing a novel 3-D spatial view of maternal-fetal structures.

Neonatal outcome in women with preterm premature rupture of membranes (PPROM) between 18 and 26 weeks.

OBJECTIVE: The aim of this study was to identify adverse neonatal outcomes and identifies the predictors of adverse neonatal outcomes in premature rupture of membranes before 26 weeks. METHODS: Data were collected between January 2005 and December 2011 from all pregnant women who presented preterm premature rupture of membranes (PPROM) between 18 and 26 complete weeks of gestation and were admitted to one of three Brazilian institutes. The adverse outcomes included mortality or the development of a severe morbidity during the length of stay in the neonatal intensive care unit (NICU). The descriptive statistics of the population were reported. A multiple logistic regression was performed for each predictor of neonatal adverse outcomes. The area under the receiver operating characteristics curves for the birth weight was calculated. RESULTS: Composite adverse outcomes during the NICU stay occurred in 82.1% (n = 23) of the cases and included 33 (54%) neonatal deaths, 19 (67.8%) cases of retinopathy of prematurity (ROP), 13 (46.4%) cases of pulmonary hypoplasia (BPD), 8 (28.5%) cases of periventricular-intraventricular hemorrhage (PIH) and 3 (10.7%) cases of periventricular leukomalacia (PVL). Only 17.8% (n = 5) of the neonates survived without morbidity. The area under the curve for the birth weight was 0.90 (95% IC: 0.81-0.98) for the prediction of mortality. CONCLUSIONS: PPROM before 26 weeks has a high morbidity and mortality, and the significant predictors of neonatal mortality and adverse outcomes were antibiotic prophylaxis, latency period, GA at birth and birth weight. Nevertheless, the only independent significant predictor of survival rate was birth weight.

3D ultrasonography to evaluate fetal urinary production rates in twin gestation: construction of a normal value curve.

OBJECTIVE: The aim of this study was to assess fetal urinary production rates (FUPR) in twin gestations using 3D ultrasonography with VOCAL® (virtual organ computer-aided analysis) and to develop a curve of normal values for the target population. METHODS: A cross-sectional study was performed in 30 normal twin pregnancies with gestational ages ranging from 20 to 34 weeks. FUPR was measured using a three-dimensional ultrasound (3D US) virtual organ computer-aided analysis (VOCAL) system. FUPR (ml/hour) was calculated during the filling phase using the equation UPR = (VFB(2) - VFB(1))/time. The values for UPR were plotted as a function of fetal biometry (biparietal diameter) to generate a nomogram. RESULTS: A total of 41 normal twin fetuses with gestational ages between 20 and 34 weeks were investigated. Eleven were excluded because of inadequate bladder contour image quality and/or the observation of micturition in one or both fetuses. Linear regression analysis of FUPR as a function of biparietal diameter (BPD) shows the normal range for UPR by fetal biometry and is expressed by the following equation: Ln(UPR) = -5.0121 + 0.0548 BPD (R(2) 0.3386, p value <.001). There was no statistically significant difference when the UPR was stratified by chorionicity. CONCLUSIONS: The use of biometric parameters to predict fetal FUPR seems to be useful. In twin pregnancies, BPD is the variable that is most closely related to FUPR. For each 1 mm increase in BPD, there is a 5% increase in FUPR. Chorionicity did not affect FUPR.

Changes in ophthalmic artery Doppler indices in hypertensive disorders during pregnancy.

OBJECTIVES: To compare the ophthalmic artery Doppler indices observed in women with singleton pregnancies complicated by hypertension and to correlate the indices observed in hypertensive pregnant women with those observed in healthy pregnant women. METHODS: Ophthalmic artery Doppler indices were compared between 30 women with mild preeclampsia, 30 women with severe preeclampsia, and 30 women with chronic hypertension at 20 to 40 weeks' gestation. The control group consisted of 289 normotensive pregnant women. The resistive index, pulsatility index, and peak ratio were measured in the right eye. The mean and standard deviation were calculated for each group. Analysis of variance and the Tukey method were used to compare the means of the Doppler indices between groups. Receiver operating characteristic curves were used to determine the predictive power of the Doppler indices for identification of women with severe preeclampsia. P < .05 was considered statistically significant. RESULTS: Significant differences were found between the resistive index, pulsatility index, and peak ratio in women with severe preeclampsia compared to the other groups. The means ± SDs for the resistive index, pulsatility index, and pulse ratio in women with severe preeclampsia were 0.63 ± 0.09, 1.13 ± 0.31, and 0.89 ± 0.12, respectively. The optimal cutoff values for the resistive index, pulsatility index and the peak ratio for identification of women with severe preeclampsia were determined by the receiver operating characteristic curves to be 0.657, 1.318, and 0.784. CONCLUSIONS: Doppler imaging of the ophthalmic artery showed central overperfusion among pregnant women with severe preeclampsia. The peak ratio was the best index for discriminating between severe and mild preeclampsia or chronic hypertension.

Normal range for fetal urine production rate customized by biometry.

OBJECTIVE: The aim of this study was to develop a nomogram for fetal urine production (UPR) using biometric parameters. METHODS: A cross-sectional study was performed in 110 normal singleton fetuses with gestational ages ranging from 20 to 40 weeks. UPR was measured using tridimensional ultrasound (3-DUS) virtual organ computer-aided analysis. UPR (ml/h) was calculated during the filling phase using the equation, UPR = (VFB2-VFB1)/time. The values for UPR were plotted as a function of fetal biometry (femur, humerus, abdominal circumference, and head circumference and biparietal diameter) to obtain a nomogram for each parameter. RESULTS: A total of 110 normal singleton fetuses with gestational age between 20 and 40 weeks were investigated. Five of them were excluded because the image quality was insufficient for correct visualization of the bladder contour. Linear regression analysis of UPR as a function of femur, humerus, abdominal circumference, and head circumference and biparietal diameter generated curves that represents the normal range for UPR by fetal biometry, and expressed by the following equations: (1) Humerus length (HL): ln (UPR) = -5.9546 + 0.0958 × HL (mm); (R(2) 0.6422); (2) abdominal circumference: ln (UPR) = -1.0981 + 0.158 × AC (mm); (R(2) 0.6328); (3) femur length: ln (UPR) = -1.5133 + 0.0803 × FL (mm); (R(2) 0.6611); (4) biparietal diameter ln (UPR) = -7.8779 + 0.2368 × BPD-0.0012 × DBP(2); (R(2) 0.7066). Although BPD has the highest correlation coefficient (R(2) 0.7066) there was no statistical significant difference between the parameters investigated for UPR prediction. CONCLUSION: The use of biometric parameters for prediction of fetal UPR seems to be useful and can avoid the necessity of building local nomograms for different populations. The same strategy should be considered to other fields in fetal medicine.

Doppler velocimetry of ductus venous in preterm fetuses with brain sparing effect: neonatal outcome.

OBJECTIVE: to evaluate the relationship between ductus venous (DV) and Doppler velocimetry in neonatal outcome in severe compromised preterm fetuses. METHODS: the study was designed as an observational and cross-sectional study with 52 premature neonates with brain sparing effect. The criteria of neonatal severe morbidity were: severe intraventricular hemorrhage (grades 3 or 4), retinopathy of prematurity (grade 3 or 4), cystic periventricular leukomalatia, bronchopneumo dysplasia and neonatal mortality. The fetuses were divided in two groups: group 0 - all the fetuses with ventricular systole/atrial contraction (S/A) in DV ratio values less them 3.4; group 1 - fetuses with values of S/A ratio greater than 3.4. RESULTS: 42% of fetuses showed abnormal S/A ratio in DV and 48% showed birth weight below percentile 3 for gestational age. There was no statistical significance comparing the 02 groups according to bronchopneumo dysplasia, retinopathy of prematurity (grade 3 or 4) and intraventricular hemorrhage (grade 3 or 4). Only one fetus presented cystic periventricular leukomalatia. We found statistically significant association between abnormal DV S/A ratio and neonatal mortality (CI 95%, 1.28 -38.22, p< 0.002). CONCLUSIONS: our results suggest that abnormal DV blood flow detected by Doppler examination isn't associated with severe neonatal morbidity but with neonatal mortality.

Doppler velocimetry of the ophthalmic artery: reproducibility of blood flow velocity measurements.

OBJECTIVES: The aim of this study was to investigate the interobserver reliability for measuring ophthalmic artery Doppler indices. METHODS: Healthy women (n = 30) were evaluated. The resistive index, pulsatility index, and peak ratio were determined by two independent observers who were blind to each other. A paired t test was used for the comparison of paired samples in the cases of replication between observers. Pearson product-moment correlation was used to study the relationship between the samples. The Bland-Altman graphic approach was used to investigate the agreement between observers. RESULTS: No significant differences were found between the values obtained by the two independent observers for the resistive index and pulsatility index. The difference observed between the values obtained by the observers for the peak ratio was 0.02. CONCLUSIONS: Doppler velocimetry is a reproducible technique for evaluation of the resistive index and pulsatility index. For analysis of the peak ratio, an interval of ±0.02 should be considered for the measurement.

Normal range for fetal urine production rate by 3-D ultrasound in Brazilian population.

OBJECTIVE: The aim of the present study was to establish the normal range for fetal UPR in the Brazilian population. METHODS: A cross-sectional study was performed in 167 normal singleton fetuses with gestational ages ranging from 20 to 40 weeks. UPR was measured using 3-D US virtual organ computer-aided analysis (VOCAL). UPR (in ml/h) was calculated during the filling phase by using the equation UPR = (VFB(2) - VFB(1))/time. The values for UPR were plotted as a function of gestational age to obtain a nomogram. Interobserver reliability was also investigated by using Spearman's rank correlation for comparison of paired samples in cases of replication between observers. Bland and Altman's graphical approach was utilized to investigate the agreement between observers. RESULTS: A total of 167 normal singleton fetuses with gestational age between 20 and 40 weeks were investigated. Nine of them were excluded because the image quality was insufficient for correct visualization of the bladder contour. Linear regression analysis of UPR as a function of gestational age generated a curve that represents the normal range for fetal UPR in the Brazilian population, and is expressed by the equation: Ln (UPR) = -13.7508 + 0.7094 × GA - 0.0092 × GA(2) (R (2) 0.60). A correlation coefficient of 0.9994 (Spearman) was obtained. Bland and Altman's graphic plots confirm the significant agreement between observers. CONCLUSION: Small differences were observed between the values for UPR observed in our sample and the normal values described in previous studies. These differences were observed mainly in late third trimester and are probably related to population biometric differences.

Doppler velocimetry of the ophthalmic artery in normal pregnancy: reference values.

OBJECTIVE: This study aimed at analyzing the correlation between ophthalmic Doppler indices and gestational age (GA) in healthy patients with singleton pregnancies. Intraobserver reproducibility and right-to-left eye correlation were also evaluated. METHODS: Healthy pregnant women (n = 289) at 20 to 40 weeks' GA were evaluated. The resistive index (RI), pulsatility index (PI), and peak ratio (PR) were determined by 2 measurements in each eye. Comparisons were performed first between the 2 measurements in each eye and later between the right and left eyes. Spearman rank correlation was used to analyze the relationship of the RI, PI, and PR with GA. Linear regression analysis was also performed. RESULTS: No significant differences were found between the values obtained for the first and the second measurements in each eye and those for the RI, PI, and PR in the right and left eyes. There was a significant decrease in RI and PI values with advancing GA, however (rho = -0.264 and -0.1192, respectively), with low R(2) values for both. Thus, only a small proportion of the variations observed in the RI and PI was associated with changes in GA. No significant difference was found between the PR values with regard to GA intervals. CONCLUSIONS: Doppler velocimetry is a reproducible technique for evaluation of the RI, PI, and PR in the ophthalmic artery. Unilateral analysis of these indices can be used. Linear regression analysis indicated that other factors were associated with a decrease in the RI and PI values with advancing GA. No significant change was observed in the PR values throughout normal pregnancy.