Multivariable analysis of tests for the diagnosis of intrauterine growth restriction.

OBJECTIVES: To describe how data from antenatal fetal ultrasound biometry, amniotic fluid index and umbilical artery Doppler can be appropriately combined using multivariable models and to investigate how the addition of these ultrasound parameters influences the ability to predict intrauterine growth restriction (IUGR). METHODS: This was a prospective cohort study involving 274 low-risk pregnancies undergoing serial ultrasound examination at predetermined intervals. Standard deviation (Z) scores of the last values for fetal abdominal area (FAA), growth velocity of the FAA, amniotic fluid index (AFI) and umbilical artery Doppler pulsatility index prior to delivery were calculated for 260 fetuses. Customized estimated fetal weight (cEFW) centiles were also calculated using the last EFW before delivery after adjustment for fetal gender, gestational age, birth order and maternal weight, height and ethnic origin. Following delivery the neonatal ponderal index was calculated and centile position obtained. A neonatal ponderal index <25(th) centile served as the main outcome measure for diagnosis of IUGR. Logistic regression analysis was used to delineate the predictive value of the three fetal growth tests FAA, FAA growth velocity and cEFW and the additional values of AFI and pulsatility index of the umbilical artery. RESULTS: The areas under the receiver-operating characteristics (ROC) curves (95% confidence interval) for FAA, FAA growth velocity and cEFW alone were 0.819 (0.748-0.891), 0.784 (0.699-0.869) and 0.74 (0.643-0.837), respectively, in the prediction of a neonatal ponderal index <25(th) centile. The addition of both the AFI and pulsatility index to FAA, FAA growth velocity and cEFW generated small increases in the areas, to 0.831 (0.758-0.904), 0.817 (0.735-0.899) and 0.766 (0.672-0.859), respectively. These improvements in diagnostic prediction were not statistically significant. CONCLUSIONS: The addition of AFI and umbilical artery pulsatility index to the fetal biometry parameters did not significantly increase the ROC areas in the study population. The approach applied in this study is useful in the context of hypothesis generation. Further studies using larger data sets and other predictors should be carried out using the analytical techniques outlined in this paper to determine the contribution of various antenatal tests in the prediction of IUGR.     

胎膜早破残余羊水量过少对分娩结局的影响

目的 探讨胎膜早破残余羊水量过少对分娩结局的影响.方法 选择256例胎膜早破、足月妊娠、头位、无其他产科并发症与合并症者,临产前均行B超监测羊水残余量.其中羊水指数(AFI)≤8.0 cm者86例(羊水过少组),AFI>8.0cm者170例(羊水适量组).观察分析两组患者的胎儿窘迫、新生儿窒息、宫内感染、手术产率.结果 剖宫产率、阴道助产率、胎儿窘迫发生率、新生儿窒息率、宫内感染发病率,两组间差异具有显著性(P＜0.05).结论 胎膜早破残余羊水量与围生儿预后及分娩方式密切相关,羊水残余量过少时,宫内感染率、围生儿发病率及手术产率明显增高.因此,胎膜早破者要及早监测残余羊水量,产程中严密监护,及时发现产程异常、胎儿心率异常及羊水性状气味异常,及时选取正确的分娩方式,以提高产科质量.     

胎膜早破后残余羊水量对母婴的影响

目的探讨胎膜早破后残余羊水量对母婴的影响。方法对397例胎膜早破孕妇的临床资料进行回顾性分析,根据残余羊水指数（AFI）的多少分成3组,即羊水正常组（80mm〈AFI≤180mm）,羊水偏少组（50mm（AFI≤80mm）,羊水过少组（AFI≤50ram）,对不同残余羊水指数孕妇的分娩方式及胎儿窘迫、宫内感染率、新生儿发病率进行比较。结果羊水过少组较羊水偏少组及羊水正常组剖宫产率、胎儿窘迫发生率、胎儿宫内感染率、新生儿发病率高,差异有统计学意义。结论胎膜早破后残余羊水量过少会促使宫内感染率增加,影响胎儿、新生儿的生命安全,残余羊水指数可作为临床监测胎儿宫内安危的指标,予合理干预,选择正确的分娩方式,提高产科质量。     

Correlation between fetal gastric size and amniotic fluid volume

PURPOSE: Since abnormal conditions of the fetal digestive tract may alter both amniotic fluid volume and fetal gastric volume, we sought to determine whether amniotic fluid volume is correlated with fetal gastric volume in normal pregnancy. METHODS: A total of 280 fetal gastric size measurements were made prospectively from routine sonographic examinations of women with normal singleton pregnancies between 16 and 42 weeks of gestation. The fetal stomach was defined as the largest area including the pyloric site on transverse or oblique real-time sonographic scans. Gastric volume was calculated according to the formula for a prolate ellipsoid. The amniotic fluid index (AFI) was used for the evaluation of amniotic fluid volume. RESULTS: Both fetal gastric volume and AFI were significantly correlated with gestational age (R2= 0.422 and R2= 0.128, respectively). Only a weak correlation was found between gastric volume and AFI (R2= 0.036, p <0.001). On multivariate linear regression analysis adjusting for gestational age and fetal biometric measurements, gastric volume was not an independent and significant predictor of AFI. CONCLUSIONS: Although sonographically determined fetal gastric volume measurements appear to be useful in the assessment of fetal digestive tract anomalies, fetal gastric volume has no clinically significant effect on the amniotic fluid volume in normal pregnancy.     

Staging of intrauterine growth-restricted fetuses.

OBJECTIVE: The purpose of this study was to evaluate the value of cardiovascular, ultrasonographic, and clinical parameters for developing a staging classification of intrauterine growth-restricted (IUGR) fetuses delivered at 32 weeks or earlier. METHODS: Intrauterine growth restriction was defined as the presence of an estimated fetal weight below the 10th percentile. Intrauterine growth-restricted fetuses were staged according to the following parameters, with the presence of any 1 parameter in a stage placing the fetus in that stage: stage I, an abnormal umbilical artery or middle cerebral artery pulsatility index; stage II, an abnormal middle cerebral artery peak systolic velocity, umbilical artery absent/reversed diastolic flow, umbilical vein pulsation and an abnormal ductus venosus pulsatility index; and stage III, reversed flow at the ductus venosus or reversed flow at the umbilical vein, an abnormal tricuspid E wave (early ventricular filling)/A wave (late ventricular filling) ratio, and tricuspid regurgitation. Each stage was divided into A (amniotic fluid index [AFI] <5 cm) and B (AFI >5 cm). The presence of maternal abnormalities was also reported. RESULTS: Seventy-four IUGR fetuses delivered at 32 weeks or earlier were included. Gestational age at delivery was greater in stage I fetuses compared with the other stages. Birth weight decreased with advancing stages. Stage III fetuses had the lowest AFI. There was a direct correlation between the severity of staging and both perinatal mortality and mortality occurring between 20 weeks' gestation and before the neonates were discharged from the hospital (P < .05). CONCLUSIONS: The staging system proposed here may allow comparison of outcome data for IUGR fetuses and may be valuable in determining more timely delivery for these high-risk fetuses.     

Single and serial estimates of amniotic fluid volume and umbilical artery resistance in the prediction of intrauterine growth restriction.

OBJECTIVES: To determine whether single or serial estimates of both the amniotic fluid index (AFI) or pulsatility index (PI) of the umbilical artery Doppler waveform can usefully identify infants with anthropometric features of intrauterine growth restriction (IUGR). METHODS: A total of 274 women underwent serial antenatal ultrasound examinations at predetermined intervals. Four biophysical parameters were considered: AFI and PI prior to delivery and change in AFI and PI over a 28-day period in the third trimester. All values were expressed as standard deviation scores. IUGR was diagnosed if the neonate demonstrated skinfold thickness < 10th centile, ponderal index < 25th centile or mid-arm circumference to occipitofrontal circumference (MAC:OFC) < -1 SD. Receiver operator characteristic curves were used to determine an optimal cut-off point, and test performance of the biophysical parameters were expressed as likelihood ratios (LR). RESULTS: The test performances of all four ultrasound parameters for any of the three diagnostic criteria for IUGR was poor. The highest positive LR was only 2.5 (95% CI 1.5-4.1) for PI prior to delivery in the prediction of ponderal index < 25th centile. CONCLUSION: Despite positive associations between single and serial estimates of AFI and PI with abnormal neonatal morphometry, the likelihood ratios remained low. The results of this study do not support the use of single or serial estimates of AFI or umbilical artery PI in the prediction of IUGR.     

Amniotic fluid and the clinical relevance of the sonographically estimated amniotic fluid volume: oligohydramnios

The amniotic fluid volume (AFV) is regulated by several systems, including the in-tramembranous pathway, fetal production (fetal urine and lung fluid) and uptake (fetal swallowing), and the balance of fluid movement via osmotic gradients. The normal AFV across gestation has not been clearly defined; consequently, abnormal volumes are also poorly defined. Actual AFVs can be measured by dye dilution techniques and directly measured at cesarean delivery; however, these techniques are time-consuming, are invasive, and require laboratory support, and direct measurement can only be done at cesarean delivery. As a result of these limitations, the AFV is estimated by the amniotic fluid index (AFI), the single deepest pocket, and subjective assessment of the AFV. Unfortunately, sonographic estimates of the AFV correlate poorly with dye-determined or directly measured amniotic fluid. The recent use of color Doppler sonography has not improved the diagnostic accuracy of sonographic estimates of the AFV but instead has led to overdiagnosis of oligohydramnios. The relationship between the fixed cutoffs of an AFI of 5 cm or less and a single deepest pocket of 2 cm or less for identifying adverse pregnancy outcomes is uncertain. The use of the single deepest pocket compared to the AFI to identify oligohydramnios in at-risk pregnancies seems to be a better choice because the use of the AFI leads to an increase in the diagnosis of oligohydramnios, resulting in more labor inductions and cesarean deliveries without any improvement in peripartum outcomes.     

Predicting macrosomia.

OBJECTIVE: The purpose of this study was to evaluate the prediction of fetal macrosomia based on ultrasound estimates of fetal weight and amniotic fluid volume combined with clinical risk factors. METHODS: A retrospective cohort study of women undergoing indicated obstetric ultrasound examinations within 7 days of delivery was conducted. RESULTS: A total of 3115 women gave birth within 7 days of ultrasound examinations that included an estimated fetal weight (EFW) and an amniotic fluid index (AFI). Clinical risk factors were associated with an 8% positive predictive value for a birth weight of 4000 g or higher. Adding an ultrasound EFW of 4000 g or higher increased the positive predictive value to 62%. Adding an AFI of 20 cm or higher to the clinical risk factors and the ultrasound EFW further increased the positive predictive value to 71%. CONCLUSIONS: An ultrasound EFW of 4000 g or higher within 1 week of delivery combined with clinical risk factors and an increased AFI is associated with macrosomia at birth in 71% of cases.     

High perinatal survival in monoamniotic twins managed by prophylactic sulindac, intensive ultrasound surveillance, and Cesarean delivery at 32 weeks' gestation.

OBJECTIVES: Increased perinatal mortality in monoamniotic twin pregnancies is attributed to cord accidents in utero and at delivery. We evaluated the following parameters in monoamniotic pregnancies: (1) the incidence of cord entanglement; (2) the effect of sulindac on amniotic fluid volume and stability of fetal lie; and (3) the perinatal outcome with our current management paradigm. METHODS: This is a retrospective review of monoamniotic pregnancies of >or=20 weeks' gestation managed with serial ultrasound surveillance, medical amnioreduction and elective Cesarean delivery at 32 weeks' gestation. Mean amniotic fluid index (AFI) and change in AFI in monoamniotic pregnancies managed with oral sulindac was compared with 40 gestation-matched monochorionic-diamniotic controls. RESULTS: Among 44 monoamniotic pregnancies, 20 with two live structurally normal twins at 20 weeks' gestation satisfied the inclusion criteria. All fetuses survived to 28 days postnatally despite early prenatal cord entanglement in all but one case. Whereas AFI remained stable throughout gestation in the controls, the AFI fell in those patients on sulindac from a mean value of 21.0 cm (95% CI, 18.5-23.6 cm) at 20 weeks to a mean of 12.4 cm (95% CI, 10.1-14.6 cm) at 32 weeks (ANOVA P across gestation = 0.001) but mainly remained within normal limits. Fetal lie was stabilized in 11/20 cases in the monoamniotic group compared with 13/40 in the control group (P < 0.0001). CONCLUSIONS: Cord entanglement appears unpreventable, as it typically occurs in early pregnancy. Sulindac therapy reduces AFI, leads to more stable fetal lie, and may prevent intrauterine death by diminishing the risk of constricting cords that are already entangled. Perinatal survival in monoamniotic pregnancies managed by a regime of sulindac from 20 weeks' gestation, close ultrasound surveillance and elective abdominal delivery at 32 weeks' gestation seems empirically higher than that in the literature.     

Growth retardation in fetuses with gastroschisis

This study was designed to determine the prevalence of intrauterine growth restriction in neonates with gastroschisis and to evaluate the accuracy of the ultrasonographic diagnosis of intrauterine growth restriction. Birth weight and gestational age were determined for 46 infants diagnosed prenatally as having gastroschisis. Biometric data were analysed for the 30 pregnancies in which an examination was conducted within 1 week of delivery. Fetal growth parameters were compared with norms for gestational age. The prevalence of intrauterine growth restriction in the entire study group was 24% with a mean birth weight of 2401 +/- 508 g. Ultrasonographic estimated fetal weight was significantly less than birth weight (mean, 2079 +/- 508 g versus 2331 +/- 512 g, respectively; P < 0.0001). Intrauterine growth restriction was predicted in 43% of infants but was present in only 23%. The percentage difference between measured abdominal circumference and gestational age norm was significantly more than for biparietal diameter and for femur length (P < 0.001). Of the three biometric measures, only the difference between measured abdominal circumference and gestational age norms and the difference between estimated fetal weight and birth weight showed a significant correlation. Both abdominal circumference and femur length correlated with the difference between estimated fetal weight and birth weight. We conclude that the prevalence of intrauterine growth restriction is increased in infants with gastroschisis but is overestimated with prenatal ultrasonography, primarily because of smaller than average abdominal circumference measurements.     

Isolated Fetal Intra‐Abdominal Umbilical Vein Varix

This series describes a single center's experience in follow‐up and management of fetuses with an isolated fetal intra‐abdominal umbilical vein varix. All cases with a fetal intra‐abdominal umbilical vein varix that were diagnosed or referred to our medical center over 15 years were followed and managed. The definition of a fetal intra‐abdominal umbilical vein varix used was a segment dilated to 9 mm or greater or at least 50% wider than the diameter of the adjacent umbilical vein. Over the 15‐year period, our center had approximately 65,000 births with 28 cases of isolated fetal intra‐abdominal umbilical vein varices: a prevalence rate of 1 case per 2300 births. Three of the 28 cases (10.7%) had intrauterine growth restriction. Five of 30 fetuses (17%) showed turbulent flow in the varix. We had no cases of intrauterine fetal death, and 27 of the 28 neonates had good outcomes. In contrary to earlier reports, we found that when a fetal intra‐abdominal umbilical vein varix is isolated, a good fetal outcome is expected. On the basis of our experience, we have changed our policy and do not recommend inducing preterm labor. Nevertheless, close fetal surveillance until delivery is warranted.     

Polyhydramnios and fetal intrauterine growth restriction: ominous combination.

The purpose of this study was to evaluate the significance of polyhydramnios combined with intrauterine growth restriction. During a 6 year period, 39 fetuses were identified by prenatal sonography as having both polyhydramnios and intrauterine growth restriction. Polyhydramnios was defined as a four-quadrant amniotic fluid index of 24 or greater (mean 30.5, range 24 to 40). Intrauterine growth restriction was defined as estimated fetal weight less than the tenth percentile (Hadlock standards). The mean birth weight was 2213 g. Major anomalies were present postnatally in 92% (36 of 39) of fetuses. Among nine fetuses without sonographically detectable anomalies prenatally, six (67%) proved to have one or more anomalies at birth. Chromosome abnormalities were present in 38% (15 cases) including 10 fetuses with trisomy 18 and one with trisomy 13. The overall mortality rate was 59%. The combination of polyhydramnios and intrauterine growth restriction is ominous. The majority of fetuses have major anomalies or chromosome abnormalities, or both, even when other sonographic abnormalities are absent. Chromosome analysis and detailed fetal evaluation should be offered when polyhydramnios and intrauterine growth restriction are identified prenatally.     

Long-term implications of fetal growth restriction

Fetal growth restriction (FGR), or intrauterine growth restriction (IUGR), is a complication of pregnancy where the fetus does not achieve its genetic growth potential. FGR is characterized by a pathological retardation of intrauterine growth velocity in the curve of intrauterine growth. However, the FGR definition is still debated, and there is a lack of a uniform definition in the literature. True IUGR, compared to constitutional smallness, is a pathological condition in which the placenta fails to deliver an adequate supply of oxygen and nutrients to the developing fetus. Infants with IUGR, compared to appropriately grown gestational age infants, have a significantly higher risk of mortality and neonatal complications with long-term consequences. Several studies have demonstrated how suboptimal fetal growth leads to long-lasting physiological alterations for the developing fetus as well as for the newborn and adult in the future. The long-term effects of fetal growth retardation may be adaptations to poor oxygen and nutrient supply that are effective in the fetal period but deleterious in the long term through structural or functional alterations. Epidemiologic studies showed that FGR could be a contributing factor for adult chronic diseases including cardiovascular disease, metabolic syndrome, diabetes, respiratory diseases and impaired lung function, and chronic kidney disease. In this review we discussed pathophysiologic mechanisms of FGR-related complications and potential preventive measures for FGR.     

胎盘早剥48例临床分析

目的:提高胎盘早剥的早期诊断和及时治疗,降低母儿并发症.方法:回顾性分析我院2006年1月~2011年6月诊治的48例胎盘早剥的临床资料.结果:胎膜早破、妊娠期高血压疾病、胎儿生长受限为胎盘早剥的重要高危因素.主要临床表现为腹痛、子宫张力大、阴道流血、子宫压痛、胎心异常、死胎、血性羊水等.剖宫产30例,阴道产18例,产妇发生产后出血9例,DIC 2例,行次全子宫切除术1例,无孕产妇死亡.新生儿轻度窒息11例,重度窒息5例,死胎3例.结论:胎盘早剥病因多,临床表现个体差异大,及早识别和处理是降低风险,提高母婴结局的关键.     

Physiologic restriction versus genetic weight potential: study in normal fetuses and in fetuses with intrauterine growth retardation.

Physiologic weight restriction is defined as the difference between the genetic and real weight in a normal fetus. The aims of this study were (1) to obtain, in normal pregnancies, reference values of mean weight restriction between 32 and 42 weeks for both male and female fetuses, and (2) to observe how weight restriction may influence intrauterine growth retardation. In the first part of the study, 1004 ultrasonograms of 389 different women were studied and the estimated fetal weights with their regression curves were calculated and drawn for all fetuses by sex. Differences between the 50th percentile of the genetic curves in normal population and the estimated fetal weight values for each of the 1004 examinations were calculated and weight restriction 50th and 90th percentiles were described. In the second part of the study, genetic curves were constructed retrospectively for 20 fetuses with intrauterine weight restriction whose examinations were performed before week 28 and were compared with curves for the normal population. Finally, for the 20 patients with intrauterine weight restriction, differences between genetic and real weight at delivery were plotted and compared with weight restriction 50th and 90th percentiles. Also, fetuses with intrauterine weight restriction were compared according to differing degrees of restriction. Weight restriction began between 31 and 33 weeks of gestation and was earlier and marked in female fetuses. Genetic percentiles were higher in normal fetuses than in fetuses with intrauterine weight restriction. In addition, pregnancies of intrauterine growth restricted fetuses with greater degrees of weight restriction were more abnormal than those of fetuses with a lesser degree of weight restriction. Both facts imply that some of the fetuses included in the classic diagnosis of intrauterine weight restriction may be genetically small fetuses. Concepts of weight restriction and physiologic weight restriction might be applied to discriminate between normal, genetically small fetuses and fetuses affected with intrauterine growth retardation.     

Fetuses with trisomy 21 having conflicting findings on antenatal testing for fetal well-being.

OBJECTIVE: This series reports 3 cases with conflicting antenatal sonographic findings: intrauterine growth restriction, absent or reversed end-diastolic flow in umbilical artery Doppler imaging, and reassuring biophysical test results. METHODS: We conducted a retrospective review of medical records. RESULTS: Three fetuses had intrauterine growth restriction and absent or reversed end-diastolic flow in umbilical artery Doppler studies, but the biophysical test results and amniotic fluid volume assessment were normal. We found no other signs of fetal jeopardy from placental insufficiency. In these cases, trisomy 21 was established after birth by karyotyping. Ventricular septal defects and aortic regurgitation were noted in 2 of the 3 affected fetuses. CONCLUSIONS: When there is an unusual combination of antenatal sonographic findings such as presented here, fetal cardiac abnormalities and aneuploidy should be considered.     

Placental multiple chorionic cysts in maternal scleroderma

We present a case of a pregnant woman with scleroderma (Ssc) whose placenta showed multiple chorionic cysts and severe fibrotic changes and large infarcted areas at the maternal side. Fetal growth was appropriate for gestational age and amniotic fluid volume was normal, but fetal tachycardia, loss of variability, and late deceleration were detected by non-stress test at 29 weeks of gestation. She was diagnosed as having non-reassuring fetal status and delivered a female baby who weighed 1092 g (Apgar score 6/9) by Caesarean section. Placental surface cysts are rare findings and their effect on pregnancy is poorly understood, but an association with intrauterine growth restriction (IUGR) has been reported. This is the first report of a pregnant woman with scleroderma showing multiple placental cysts.     

Pregnancy in end-stage renal disease patients and treatment with peritoneal dialysis: report of two cases.

Pregnancy in end-stage renal disease patients is infrequent and is associated with fetal loss, premature delivery, intrauterine growth restriction, and lack of control of or exacerbation of or onset of hypertension. Even after replacement of renal function, the prognosis for the patient and the fetus is poor. A point of controversy is the renal replacement therapy method. This report is based on two clinical cases of pregnancy in peritoneal dialysis patients that resulted in full-term delivery. Adequate metabolic and blood pressure control was achieved during pregnancy, the only mutual complication being the presence of polyhydramnios. However, both infants were healthy for their gestational age and without neonatal complications. We may conclude that peritoneal dialysis is an acceptable therapeutic option for pregnant patients and their fetuses.     

产前超声及胎儿磁共振对先天性食管闭锁的诊断价值

目的:提高对先天性食管闭锁(CEA)的认识,探讨产前超声及胎儿MRI对CEA的临床价值.方法:回顾性分析29例经临床证实的CEA胎儿产前超声及胎儿MRI资料.纳入29例正常胎儿作为对照组.分析CEA影像征象,比较组间羊水深度(AFD)、羊水指数(AFI)、双顶径(BPD)、头围(HC)、腹围(AC)、股骨径(FL)、脐...     

胎儿脐动脉超声血流分型对单绒毛膜双胎妊娠sIUGR预后的影响

目的探讨胎儿脐动脉超声血流分型对单绒毛膜双胎妊娠选择性宫内生长受限预后的影响.方法将91例羊绒毛膜双胎妊娠选择性宫内生长受限孕妇设为试验组,选取同期来我院就诊的正常双胎妊娠产妇31例设为对照组.两组均予以彩色多普勒超声诊断仪进行超声检查,记录两组胎儿预后和妊娠结局,比较不同预后单绒毛膜双胎妊娠选择性宫内生长受限胎儿的超声指标.结果试验组小胎儿宫内死亡率显著高于对照组(P<0.01);大、小胎儿出生体质量均显著低于对照组(P<0.01).试验组不同选择性宫内生长受限分型两胎儿、小胎儿宫内死亡率比较差异无统计学意义(P>0.05);Ⅱ型小胎儿出生体质量显著低于Ⅰ型和Ⅱ型小胎儿(P<0.05),Ⅰ型与Ⅲ型小胎儿出生体质量比较差异无统计学意义(P>0.05).实验组死亡小胎儿羊水过少、选择性宫内生长受限分型Ⅱ型检出率显著高于存活胎儿(P<0.05或0.01),帆状脐带、双胎体质量差异>25%检出率与存活胎儿比较差异无统计学意义(P>0.05).结论羊水过少及选择性宫内生长受限分型是影响单绒毛膜双胎妊娠选择性宫内生长受限胎儿预后的重要原因,对该类孕妇采用超声检查能够提供较为可靠的临床评价依据.