A comparison of single versus multiple growth ultrasonographic examinations in predicting birth weight

OBJECTIVE: Our purpose was to determine whether two or more ultrasonographic fetal growth assessments provide a superior estimate of birth weight than does a single examination. STUDY DESIGN: Five hundred and eighty five ultrasonographic procedures were performed in 263 patients, divided into single (n = 249) and multiple (n = 247) examination groups. Ultrasonographically estimated fetal weight percentiles and abdominal circumference percentiles were compared with gestationally corrected birth weight percentiles. After the gestational age range with the fewest errors in birth weight percentile prediction (32 to 36 weeks) was determined, patients with a single examination in this range were assigned to the single examination group. In the group with multiple examinations averaged ultrasonographic percentiles were used to predict birth weight percentile. Mean absolute and percentage errors were compared for predictive accuracy by means of analysis of variance and Student t test. RESULTS: There was a linear correlation between the estimated fetal weight and abdominal circumference percentiles and the birth weight percentile, (r = 0.72, p < 0.0001). The accuracy of birth weight percentile predictions was similar whether one or multiple examinations were performed in the third trimester. Both the abdominal circumference percentile and estimated fetal weight percentile underpredicted birth weight, although the abdominal circumference percentile errors (1% to 2%) were statistically smaller than those derived from estimated fetal weights percentile (9% to 11%, p < 0.0001). Both abdominal circumference percentile and estimated fetal weights percentile consistently overidentified fetuses <10th percentile (small for gestational age) and underidentified fetuses >90th percentile (large for gestational age). However, multiple abdominal circumference percentile measurements resulted in improved predictions for small for gestational age (sensitivity 100%, specificity 88%) and large for gestational age (sensitivity 84%, specificity 100%). CONCLUSIONS: With either the single or multiple examination approach birth weight percentile estimates were within 10% of the actual birth weight percentile approximately 50% of the time. Multiple ultrasonographic examinations provided little improvement in prediction of birth weight compared with a single observation. Multiple measurements of the abdominal circumference percentile may provide improved accuracy in identifying large for gestational age and small for gestational age fetuses. (AM J Obstet Gynecol 1994;170:1600-6.)     

Treatment of severe congenital diaphragmatic hernia by fetal tracheal occlusion: clinical experience with fifteen cases

OBJECTIVE: Our purpose was to determine whether prenatal tracheal occlusion improves survival in a selected population of fetuses affected by severe congenital diaphragmatic hernia. STUDY DESIGN: Fetuses with isolated congenital diaphragmatic hernia were selected as candidates for fetal intervention by specific criteria designed to predict a 90% mortality rate with conventional postnatal treatment. RESULTS: Fifteen fetuses underwent tracheal occlusion with 5 survivors (33%). Two fetuses were lost to early preterm labor. In 13 mothers, postoperative gestation ranged from 19 to 68 days, with a mean duration of pregnancy after tracheal occlusion of 38 days. The 5 survivors were hospitalized for an average of 76 days. Despite dramatic lung growth in some fetuses after tracheal occlusion, intensive management was required, and most deaths were caused by respiratory insufficiency. CONCLUSION: Prenatal tracheal occlusion can result in impressive lung growth in a subset of fetuses with severe congenital diaphragmatic hernia. However, survival remains compromised by pulmonary functional abnormality and the consequences of prematurity.     

Impact of maternal cigarette smoking on fetal growth and body composition

OBJECTIVE: The aim of this study was to determine the impact of maternal cigarette smoking on the fetal accretion of fat and lean body mass. We hypothesized that maternal smoking would result in a reduction in the deposition of lean body mass. STUDY DESIGN: Longitudinal ultrasonographic examinations on 65 singleton fetuses without anomalies of smoking mothers were compared with 36 singleton fetuses without anomalies of nonsmoking mothers. A total of 214 ultrasonographic examinations were performed between 27 and 37 weeks' gestation. All subjects underwent at least 2 ultrasonographic examinations separated by 4 weeks. We compared the slopes of the growth curves for individual morphometric parameters including head circumference, femur length, abdominal circumference, thigh muscle area, thigh fat area, estimated fetal weight and percentage of thigh fat between groups. Analysis was performed with a repeated measures analysis of covariance. Potential covariates included prepregnancy body mass index (in kilograms per square meter), weight gain during pregnancy, maternal age, parity, and fetal sex recorded at birth. Demographic variables are expressed as mean +/- SD; fetal measurements are expressed as mean +/- SE. Both t tests and chi(2) analyses were used to compare groups with respect to demographic variables. P <.05 was accepted for significance. RESULTS: There were no significant differences between groups in maternal prepregnancy weight, maternal height, maternal prepregnancy body mass index, weight gain in pregnancy, parity, or fetal sex. Smokers were younger than nonsmokers (smokers, 23.7 +/- 6.0 years; nonsmokers, 31.8 +/- 6. 0 years; P <.0001), and neonatal weight was reduced among smokers (smokers, 3269 +/- 507 g; nonsmokers, 3519 +/- 411 g; P <.01). There were no differences in the growth rates of head circumference (P =. 79) and femur length (P =.67). Growth rates of abdominal circumference (smokers, 9.0 +/- 0.3 mm/wk; nonsmokers, 10.3 +/- 0.5 mm/wk; P =.01), estimated fetal weight (smokers, 171 +/- 5.4 g/wk; nonsmokers, 193 +/- 8.0 g/wk; P =.008), and muscle area (smokers, 64. 1 +/- 3.8 mm(2)/wk; nonsmokers, 76.4 +/- 5.6 mm(2)/wk; P =.03) were significantly reduced among smokers. There was a reduction in the rate of fat deposition in the thighs of fetuses of smoking mothers (smokers, 38.7 +/- 3.7 mm(2)/wk; nonsmokers, 54.6 +/- 5.4 mm(2)/wk; P =.004); however there was no absolute difference in the amount of fat measured in the thigh between 33 and 37 weeks' gestation. CONCLUSION: We detected reduced fetal growth that selectively affected abdominal circumference and peripheral muscle mass while not affecting head circumference and femur length in fetuses of smoking mothers. The effect of cigarette smoking on fetal fat deposition was less clear. Cigarette smoking appears to have a selective effect within lean body mass compartments, with affected compartments including peripheral fetal muscle. The findings of a reduction in abdominal circumference growth compared with control subjects in combination with no difference in subcutaneous fat content beyond 33 weeks' gestation are potentially explained by a reduction in fetal liver size that may result from maternal smoking.     

超声诊断胎儿肺发育不良的临床价值

目的 探讨多个超声指标用于产前诊断胎儿肺发育不良的临床价值.方法 应用彩色多普勒超声诊断仪,检查271例正常胎儿,建立5个超声指标(肺面积、肺面积与胎儿质量比、胸围与腹围比、肺面积与胸廓面积比、肺面积与头围比)的正常值范围,以低于正常范围二倍标准差为肺发育不良胎儿判断标准.通过对30例肺发育不良高危胎儿的研究,并与尸体解剖及追踪结果对照,比较各超声指标的临床价值.结果 肺面积及肺面积与头围比随孕周增加而增加,肺面积与胎儿质量比随孕周增加而减少,胸围与腹围比、肺面积与胸廓面积比随孕周增加变化较小.肺面积、肺面积与胎儿质量比、胸围与腹围比、肺面积与胸廓面积比、肺面积与头围比用于产前诊断胎儿肺发育不良的准确率分别为83%、97%、50%、70%、87%.肺面积与胎儿质量比诊断准确率最高,灵敏度为95%(20/21),特异度为9/9,阳性预测值为100%(20/20).结论 肺面积与胎儿质量比能较好地预测致死性肺发育不良,具有临床实用性.     

Encouraging early clinical experience with deliberately delayed temporary fetoscopic tracheal occlusion for the prenatal treatment of life-threatening right and left congenital diaphragmatic hernias

OBJECTIVE: In order to assess the effect of deliberately delayed percutaneous fetoscopic tracheal occlusion on survival of fetuses with life-threatening congenital diaphragmatic hernia. METHODS: Eight fetuses with life-threatening congenital diaphragmatic hernia underwent fetoscopic tracheal balloon occlusion between 29 + 0 and 32 + 4 weeks of gestation. Delayed occlusion was chosen in order to minimize potentially negative pulmonary effects from premature delivery as a result of fetal surgery. In addition, we wanted to become able to provide all available postnatal intensive care treatment means in these patients. RESULTS: Six of the 8 fetuses survived to discharge from hospital. CONCLUSION: Delayed fetoscopic tracheal balloon occlusion may be rewarded with lung growth sufficient to allow survival of fetuses with life-threatening congenital diaphragmatic hernia.     

Correctly identifying the macrosomic fetus: improving ultrasonography-based prediction

OBJECTIVE: Our goal was to improve the accuracy of estimating fetal weights among macrosomic fetuses with the traditional measurements of abdominal circumference, femur length, and head circumference. STUDY DESIGN: We used 4831 cases without anomalies from an ultrasonography laboratory database with an estimated fetal weight obtained a maximum of 14 days before delivery. Abdominal circumference, femur length, and head circumference were each regressed on birth weight to obtain estimated fetal weight by abdominal circumference, femur length, and head circumference, respectively. We compared the individual variation for estimated fetal weight by abdominal circumference, femur length, and head circumference by calculating a within-subject standard deviation to quantify the level of disparity. We adjusted the estimated fetal weight to the date of delivery and for dependencies on maternal diabetes mellitus, weight, and height. We then weighted cases with birth weight >4500 g and diabetic cases with birth weight >4000 g 20-fold (weighted estimated fetal weight) for the purpose of creating a favorable bias for classifying these cases. The equation of Hadlock et al, with abdominal circumference, femur length, and head circumference, was applied as a benchmark estimated fetal weight. RESULTS: Of the 4831 newborns, 308 (6.4%) had a birth weight >4000 g, and 56 (1.2%) had a birth weight >4500 g. There were 154 pregnancies complicated by diabetes mellitus; 26 (16.9%) of the resulting infants weighed >4000 g, and 5 (3.2%) weighed >4500 g. At 95% specificity, the weighted estimated fetal weight had a sensitivity of 85.7% at a cut point of 3912 g, compared with a sensitivity of 71.4% at 3604 g by use of the estimated fetal weight of Hadlock et al. CONCLUSIONS: We were able to improve the accuracy of identifying the macrosomic fetus compared to reliance on the equation by Hadlock et al. A fetus was found to be at significantly increased risk for birth weight >4000 g when the estimated fetal weight based on abdominal circumference is larger than that based on either head circumference or femur length or when there is a large within-subject variance in estimated fetal weight based on abdominal circumference, femur length, and head circumference. We also found that there were significantly different groups of patients whose estimated fetal weights require different equations for better estimates. Even given ultrasonographic measurements, taking into account maternal height, weight, and presence of diabetes mellitus can improve macrosomia detection. Although these findings remain to be optimized and validated, the approach used here appears to yield better predictions than the current "one function fits all" approach.     

Estimation of birth weight by use of ultrasonographic formulas targeted to large-, appropriate-, and small-for-gestational-age fetuses

This report sought to determine whether estimates of fetal weight are enhanced by using ultrasonographic formulas targeted to the large-, appropriate-, and small-for-gestational-age fetus in both preterm and term pregnancies. Ultrasonographic fetal measurements from 575 singleton pregnancies were obtained within 7 days of delivery. The first 194 fetuses were classified into three groups on the basis of the growth percentile rank of the abdominal circumference (greater than or equal to 90%, greater than 5% and less than 90%, and less than or equal to 5%). Regression analyses were performed to generate three formulas for estimating fetal weight on the basis of the following: Gestational age (weeks) + Head circumference (cm) + 2 x Abdominal circumference (cm) + Femur length (cm). This mathematic model allowed formulation of accurate and concise tables relating the sum of these measurements to estimated birth weight. The accuracy of these formulas was then prospectively compared, first, with the formula published by Hadlock et al. (in 32 large-, 279 appropriate-, and 70 small-for-gestational-age fetuses) and second, with the formula of Weiner et al. (in 82 preterm fetuses). The difference between actual and estimated birth weights generated by the three study formulas had no systemic error (t test, p greater than 0.05). Cumulatively, there was a statistically significant reduction of random error in the birth weight estimates by use of the three study formulas versus the best single formulas of Hadlock et al. (2 SD reduced from 21.6% to 19.8% and absolute 2 SD reduced from 15.6% to 12.2%). Additionally, the three study formulas resulted in a statistically significant reduction in the absolute 2 SD error compared with the best formula by Weiner et al. in fetuses less than or equal to 34 weeks' gestation (2 SD reduced from 19.1% to 13.6%).     

Sonographically estimated fetal weight percentile as a predictor of preterm delivery

OBJECTIVE: To evaluate the association between relative growth restriction and preterm birth. STUDY METHODS: Pregnant women referred for sonographic fetal weight assessments between 24 and 34 weeks of gestation were studied for gestational age at delivery. If a patient underwent more than one study, only the last one was considered. Patients with delivery induced iatrogenically or with abnormal growth patterns due to known pathology, such as maternal diabetes or fetal congenital anomaly, were excluded. A gestational age of 37 weeks or less was considered preterm and a gestational age of more than 37 weeks at delivery was considered term. Fetal weight estimation was obtained by Hadlock's formula based on biparietal diameter, femur length, and head and abdominal circumferences. The estimated fetal weight percentile was computed according to William's tables. Mean gestational age and incidence of preterm delivery for each fetal weight percentile between 1 and 100, at increments of 10, were calculated. The mean estimated fetal weight percentile, biparietal diameter, femur length, head circumferences and abdominal circumferences of preterm and term patients were compared. RESULTS: Among the 419 patients who met the inclusion criteria, duration of gestation was significantly shorter in fetuses with low estimated fetal weight percentile. The risk of preterm birth was 49% in fetuses of less than the 40th birth-weight percentile compared with a risk of 20% in fetuses of more than the 40th birth-weight percentile, representing a relative risk of 2.3. Individual fetal measurements indicate a head-sparing effect in the preterm group. CONCLUSION: Sonographically estimated fetal weight percentile measured between 24 and 34 weeks' gestation may be used as an additional and individually pertinent predictor of preterm birth.     

Prenatal diagnosis of bilateral diaphragmatic hernia by fetal sonography

This report describes a case of prenatally diagnosed bilateral diaphragmatic hernia. At 22 weeks' gestation, ultrasound revealed a cystic structure behind the fetus's heart on the axial image at the level of the cardiac four-chamber view. This suggested a left-sided congenital diaphragmatic hernia with herniation of the stomach into the left hemithorax. However, the left-to-right midline shift of the heart was minimal, which is not typical of left-sided congenital diaphragmatic hernia. Throughout the 30th week of gestation, the right and left branches of the pulmonary artery were hypoplastic compared with the values in normal fetuses of the same gestational age. The presumptive diagnosis was bilateral congenital diaphragmatic hernia. A female newborn weighing 2900 g was delivered at 37 weeks' gestation, and she died at 7 h of age. An autopsy revealed large defects on both sides of the diaphragm. In conclusion, prenatal diagnosis of bilateral diaphragmatic hernia is possible with fetal sonography.     

Fetal weight estimation formulas with head, abdominal, femur, and thigh circumference measurements

Most current sonographic techniques for estimating fetal weight involve measurements of the head, abdomen, and femur length both alone and in combination. The value of the fetal thigh circumference measurement in addition to the head, abdominal, and femur length measurements has not been investigated previously. Eighty-nine patients were scanned within 72 hours of delivery, and the following ultrasonic fetal parameters were obtained in all fetuses: biparietal diameter, head circumference, abdominal circumference, femur length, and thigh circumference. With multiple stepwise regression analysis, the best-fit formulas were developed with one, two, three, four, and five parameters, respectively. The best results were obtained by combining measurements of all five parameters: biparietal diameter, head circumference, abdominal circumference, femur length, and thigh circumference. The mean error of this formula was 6%, the mean deviation 0.3%, and the SD 7.8%. These data suggest that the addition of thigh circumference to measurements of the head, abdomen, and femur length improves the accuracy of fetal weight estimates.     

Congenital diaphragmatic hernia: an evaluation of the prognostic value of the lung-to-head ratio and other prenatal parameters

OBJECTIVES: A retrospective analysis of the prognostic significance of the lung-to-head ratio (LHR) and other prenatal parameters on the outcome of fetuses with left-sided congenital diaphragmatic hernia (CDH). METHODS: A total of 26 fetuses with isolated left CDH without chromosomal abnormalities were included. Twenty-one LHR measurements could retrospectively be calculated from the last available ultrasonographic recordings before birth. The relationship between LHR and fetal outcome and the gestational age dependency of this relation was tested. Cutoff levels as previously published were applied to determine their predictive value in this population. The association between other prenatal predictive variables and fetal outcome was also determined. Survival was defined as discharge from the hospital. RESULTS: The overall survival rate was 50%. There was a statistically significant difference between the mean LHR of the survivors compared to the mean LHR of the nonsurvivors (1.78 vs 1.02), whereas the mean gestational age of these two groups did not differ. LHR was not gestational age dependent in the prediction of fetal outcome. The cutoff levels LHR <1, 1-1.4, >1.4 showed a good applicability in the prediction of fetal outcome within the present study population with a 100% survival if LHR >1.4 and a 100% mortality if LHR <1. An intrathoracic position of the stomach, mediastinal shift, polyhydramnios as individual variables and early diagnosis (<25 weeks' gestation) revealed to be poor sonographic predictors for fetal outcome. CONCLUSION: LHR proved to be a good predictor for fetal outcome, independent of gestational age at the time of the measurement. To substantiate our observation, a prospective multicenter study is warranted.     

Three-dimensional ultrasonographic assessment of fetal lung volume as prognostic factor in isolated congenital diaphragmatic hernia

OBJECTIVE: To evaluate the potential of three-dimensional ultrasound to predict outcome in congenital diaphragmatic hernia. DESIGN: Prospective observational study. SETTING: Tertiary care centre. POPULATION: Twelve cases of isolated congenital diaphragmatic hernia (11 left-sided, 1 right-sided) and 109 controls. METHODS: Fetal lung volume was assessed by three-dimensional ultrasound using the technique of rotation of the multiplanar imaging. In the control fetuses, a logistic transformation was performed to correlate fetal lung volume with gestational age, and the confidence interval was obtained with a bootstrap resampling. A mathematical equation was then obtained allowing calculation of the expected fetal lung volume as a function of gestational age. In fetuses with congenital diaphragmatic hernia, the observed/expected lung volume ratio was compared with postnatal outcome. MAIN OUTCOME MEASURES: Neonatal mortality and pulmonary hypoplasia, which was defined as lung/body weight ratios less than 0.012. RESULTS: The expected fetal lung volume was derived from the mathematical equation: Fetal lung volume (mL) = exp (4.72/(1 + exp ((20.32 - gestational age in weeks)/6.05))). The observed/expected fetal lung volume ratio was significantly lower in the congenital diaphragmatic hernia group (median: 0.34, range: 0.16-0.66), than in the control group (median: 1.02, range: 0.62-1.97, P < 0.0001). The distribution of this ratio was significantly downshifted in the infants with congenital diaphragmatic hernia who died (median: 0.19, range: 0.18-0.66) compared with survivors (median: 0.44, range: 0.36-0.66, P= 0.04). The observed/expected fetal lung volume ratio was also correlated with the postmortem lung/body weight ratio. CONCLUSION: In isolated congenital diaphragmatic hernia, fetal lung volume measurement by three-dimensional ultrasound is a potential predictor for pulmonary hypoplasia and postnatal outcome.     

Sonographically estimated fetal weight percentile as a predictor of preterm delivery

Objective : To evaluate the association between relative growth restriction and preterm birth. Study methods : Pregnant women referred for sonographic fetal weight assessments between 24 and 34 weeks of gestation were studied for gestational age at delivery. If a patient underwent more than one study, only the last one was considered. Patients with delivery induced iatrogenically or with abnormal growth patterns due to known pathology, such as maternal diabetes or fetal congenital anomaly, were excluded. A gestational age of 37 weeks or less was considered preterm and a gestational age of more than 37 weeks at delivery was considered term. Fetal weight estimation was obtained by Hadlock's formula based on biparietal diameter, femur length, and head and abdominal circumferences. The estimated fetal weight percentile was computed according to William's tables. Mean gestational age and incidence of preterm delivery for each fetal weight percentile between 1 and 100, at increments of 10, were calculated. The mean estimated fetal weight percentile, biparietal diameter, femur length, head circumferences and abdominal circumferences of preterm and term patients were compared. Results : Among the 419 patients who met the inclusion criteria, duration of gestation was significantly shorter in fetuses with low estimated fetal weight percentile. The risk of preterm birth was 49% in fetuses of less than the 40th birth-weight percentile compared with a risk of 20% in fetuses of more than the 40th birth-weight percentile, representing a relative risk of 2.3. Individual fetal measurements indicate a head-sparing effect in the preterm group. Conclusion : Sonographically estimated fetal weight percentile measured between 24 and 34 weeks' gestation may be used as an additional and individually pertinent predictor of preterm birth.     

Fetal lung volume measurement by magnetic resonance imaging in congenital diaphragmatic hernia

Objective To study the potential for prenatal magnetic resonance imaging to predict pulmonary hypoplasia in congenital diaphragmatic hernia.
Design Prospective observational study.
Setting Tertiary care centre.
Participants Thirteen cases of congenital diaphragmatic hernia (11 left, 2 right) without associated anomalies and 74 controls.
Methods Measurements by magnetic resonance imaging of fetal lung volume were achieved. In the control fetuses, a regression analysis was performed to associate fetal lung volume with gestational age. This yielded a formula allowing calculation of the expected fetal lung volume as a function of gestational age. In the cases with congenital diaphragmatic hernia, the observed/expected fetal lung volume ratio was compared with perinatal outcome.
Main outcome measures Neonatal mortality and pulmonary hypoplasia, which was defined as lung/body weight ratios less than 0.012.
Results The expected fetal lung volume was derived from the following formula: Fetal lung volume (mL) = exp (1.24722 + 0.08939 × gestational age in weeks). The observed/expected fetal lung volume ratio was significantly lower in congenital diaphragmatic hernia (median: 0.31, range: 0.06–0.63), than in controls (median: 0.99, range: 0.42–1.94). This ratio was significantly less in the infants with congenital diaphragmatic hernia who died (median: 0.26, range: 0.06–0.63) compared with those who survived (median: 0.46, range: 0.35–0.56). The observed: expected fetal lung volume ratio was significantly correlated with the post mortem lung: body weight ratio.
Conclusion In isolated congenital diaphragmatic hernia, fetal lung volume measurement by magnetic resonance imaging is a potential predictor of pulmonary hypoplasia and postnatal outcome. Further studies are required to establish the clinical value of magnetic resonance imaging for the prenatal assessment of fetal lungs.     

Relationship of fetal growth to duration of heat stress in an ovine model of placental insufficiency.

OBJECTIVE: Intrauterine growth restriction in an ovine model occurs after exposure to environmental heat stress for 80 days beginning at 35 days' gestation. Our objective was to determine whether intrauterine growth restriction is reversible on removal of the heat stress after only 55 days of exposure; that is, does a brief exposure at a critical point of development suffice? STUDY DESIGN: Five pregnant ewes were exposed to heat stress beginning at 35 days' gestation and were removed after 55 days of exposure. Five ewes in a control group were studied as contemporaneous controls and added to data from 37 ewes in a control group previously studied. Serial fetal biometric ultrasonographic measurements (biparietal diameter, abdominal circumference, femur length, and tibia length) were obtained beginning at 50 days' gestation. Growth curves were calculated for each parameter, and comparisons were made between fetuses in the group exposed to heat stress for 55 days and 42 fetuses in the control group and 4 fetuses from a previous study that were exposed to heat for 80 days. Regression lines, 95% confidence intervals, and slopes were determined for each study group. RESULTS: Both the 55-day and the 80-day heat exposure groups showed a significant reduction in fetal and placental weights compared with the control group. Animals in the 80-day group had significantly lower fetal and placental weights than the animals in the 55-day group (P <.05). Indexes of somatic growth (abdominal circumference, femur length, and tibia length) for the control group were significantly greater than those of either the 55-day group or the 80-day group (P <.001). Asymmetric growth restriction was evident in both heat groups by a biparietal diameter/abdominal circumference ratio that was significantly higher than in the control group (P <.004 for the 55-day group and P <.001 for the 80-day group). The slopes for somatic parameters (abdominal circumference, femur length, and tibia length) versus time became significantly different between the control and 55-day groups at 77, 101, and 80 days' gestation, respectively. The 55-day group had abdominal circumference and femur length measurements that were significantly greater than those in the 80-day group. CONCLUSION: The fetuses in the 55-day and 80-day groups reflect a pattern of asymmetric intrauterine growth restriction. Our findings suggest that the initial insult affecting fetal and placental growth occurs early in gestation, but removal of fetuses after only 55 days of exposure significantly reduces the degree of fetal growth restriction compared with that found in those fetuses exposed for 80 days.     

Ultrasonographic ear length measurement in normal second- and third-trimester fetuses

OBJECTIVE: We sought to develop a nomogram for fetal ear length measurements from a large population of healthy second- and third-trimester fetuses and to investigate the correlation of fetal ear length with other standard fetal biometry measurements, as follows: biparietal diameter, head circumference, abdominal circumference, femur length, and humerus length. STUDY DESIGN: Ear length measurement was obtained prospectively in 4240 singleton fetuses between 15 and 40 weeks' gestational age. Either complete data for normal karyotype on amniocentesis or normal infant examination at birth or both were available in 2583 cases. These constituted the final study population. RESULTS: A nomogram was developed by linearly regressing ear length on gestational age (Ear length [in millimeters] = 1.076 x Gestational age [in weeks] - 7. 308). There was a high correlation between ear length and gestational age (r = 0.96; P =.0001). CONCLUSION: The results of this study provide normative data on growth of fetal ear length from 15 to 40 weeks' gestation. Good correlation was also observed between ear length and other fetal biometric measurements (biparietal diameter, head circumference, abdominal circumference, femur length, and humerus length).     

Fetal diaphragmatic hernia: the value of fetal echocardiography in the prediction of postnatal outcome

Nineteen pregnancies complicated by fetal congenital diaphragmatic hernia (CDH) referred for fetal echocardiography have been reviewed. Congenital heart disease was diagnosed prenatally in three fetuses; in one of these the pregnancy was terminated, the two other infants died in the neonatal period. The presence of the fetal stomach within the thorax or a hernia/heart area ratio greater than 1.7 was associated with a large diaphragmatic defect. Polyhydramnios was not associated with a poor postnatal outcome. Evidence of cardiac ventricular disproportion before 24 weeks gestation in isolated CDH was associated with 100% mortality. Development of ventricular disproportion during the third trimester was associated with a survival rate of 75%. In three fetuses, all of whom survived, no ventricular disproportion was detected during the third trimester examination.     

Prognostic value of pulmonary Doppler to predict response to tracheal occlusion in fetuses with congenital diaphragmatic hernia

Pulmonary Doppler may play an important role in the prediction of survival and postnatal morbidity in fetuses with congenital diaphragmatic hernia treated with fetoscopic tracheal occlusion (FETO). Spectral Doppler indexes such as pulsatility index and peak early diastolic reversed flow could help to refine the selection of fetuses that might benefit from fetal therapy. When combined with lung-to-head ratio (LHR), these Doppler indices allow to discriminate cases with moderate-to-high survival rates from fetuses with extremely low chances to survive after FETO. In addition, they discriminate groups with a high or low risk of serious neonatal morbidity in surviving fetuses. After therapy, the combined evaluation of the relative increase of LHR with the increase in lung tissue perfusion by power Doppler seems to improve the prediction of fetal survival. In conclusion, while LHR remains the strongest predictive index, Doppler measurements allow to substantially improve the accuracy in the prediction of the chances of survival of fetuses with congenital diaphragmatic hernia treated with FETO.     

Fetal diaphragmatic hernia: the value of fetal echocardiography in the prediction of postnatal outcome

Summary. Nineteen pregnancies complicated by fetal congenital diaphragmatic hernia (CDH) referred for fetal echocardiography have been reviewed. Congenital heart disease was diagnosed prenatally in three fetuses; in one of these the pregnancy was terminated, the two other infants died in the neonatal period. The presence of the fetal stomach within the thorax or a hernia/heart area ratio greater than 1·7 was associated with a large diaphragmatic defect. Polyhydramnios was not associated with a poor postnatal outcome. Evidence of cardiac ventricular disproportion before 24 weeks gestation in isolated CDH was associated with 100% mortality. Development of ventricular disproportion during the third trimester was associated with a survival rate of 75%. In three fetuses, all of whom survived, no ventricular disproportion was detected during the third trimester examination.     

Use of the fetal chest in estimating fetal weight.

OBJECTIVE: This study was designed to develop formulas using the chest circumference instead of the abdominal circumference for estimating fetal weight. STUDY DESIGN: Ultrasonographic measurements of the chest circumference, biparietal diameter, abdominal circumference, humeral length, and femoral length were obtained in 75 term fetuses of uncomplicated pregnancies within 24 hours of delivery. Three equations for fetal weight estimation that used the chest circumference, instead of the abdominal circumference, in combination with the biparietal diameter or the humeral length were developed by regression analysis. RESULTS: The average mean errors of fetal weight estimation for these equations vary from 7.1% to 7.6%. CONCLUSIONS: These equations may be used in predicting the birth weight when the fetal abdomen is altered by certain fetal abnormalities.