The transverse cerebellar diameter in estimating gestational age in the large for gestational age fetus

The transverse cerebellar diameter was measured in 62 nondiabetic and 30 diabetic women with large for gestational age fetuses. Using reference curves from 675 women with normal gestations between 14-42 weeks, head circumference and abdominal circumference overestimated gestational age significantly in both study groups, whereas the transverse cerebellar diameter did not.     

The relationship between cesarean delivery and gestational age among US singleton births

The increasing trend of delivering at earlier gestational ages has raised concerns of the impact on maternal and infant health. The delicate balance of the risks and benefits associated with continuing a pregnancy versus delivering early remains challenging. Among singleton live births in the United States, the proportion of preterm births increased from 9.7% to 10.7% between 1996 and 2004. The increase in singleton preterm births occurred primarily among those delivered by cesarean section, with the largest percentage increase in late preterm births. For all maternal racial/ethnic groups, singleton cesarean section rates increased for each gestational age group. Singleton cesarean section rates for non-Hispanic black women increased at a faster pace among all preterm gestational age groups compared with non-Hispanic white and Hispanic women. Further research is needed to understand the underlying reasons for the increase in cesarean section deliveries resulting in preterm birth.     

Fetal thyroid in two-dimensional ultrasonography: nomograms according to gestational age and biparietal diameter

Objective

To establish fetal thyroid nomograms based on gestational age and biparietal diameter and to compare obtained results with previously published data.

Study design

A cross-sectional study of 241 healthy pregnant women at 14–38 week of gestation was undertaken. Exclusion criteria were: known maternal thyroid or systemic disease, unknown date of last menstrual period, multiple pregnancy and fetal malformations. Fetal thyroid diameter (FTD), circumference (FTC) and area (FTA) were measured by two-dimensional ultrasonography and plotted against gestational age (GA) and biparietal diameter (BPD).

Results

FTD, FTC and FTA increased logarithmically to GA and BPD. Fetal thyroid measurements as a function of GA were expressed by logarithmic formulas: ln(FTD) = 3.6025–23.0315/GA, ln(FTC) = 4.6227–22.8003/GA, ln(FTA) = 6.6303–45.0831/GA. The following logarithmic formulas were obtained for fetal thyroid measurements according to BPD: ln(FTD) = 3.4068–45.4271/BPD, ln(FTC) = 4.4271–44.8359/BPD, ln(FTA) = 6.2390–88.4408/BPD. There were highly significant correlations between thyroid measurements and GA or BPD: r = 0.87–0.90, p < 0.00001.

Conclusions

We have established age-dependent and age-independent nomograms of fetal thyroid. These nomograms will enable prenatal diagnosis in fetuses at risk of thyroid disorders.     

The relationship of the nonstress test to gestational age

Five hundred ninety-three nonstress tests were performed on 41 obstetric patients, at gestational ages ranging from 20 to 40 weeks. Diagnoses included 10 cases of prematurity, six cases of diabetes mellitus, five cases of collagen-vascular disease, five cases of poor obstetric history, three cases of cardiac arrhythmia, and one case each of asthma, polyhydramnios, leukemia, nonimmune fetal hydrops; and eight volunteers were without high-risk factors. All neonates had a 5-minute Apgar score greater than 8; 29 neonates weighed greater than or equal to 2500 gm, 12 weighed less than 2500 gm, and four weighed less than 1500 gm. One neonate died of prematurity, and one was small for gestational age. There were no congenital anomalies. There was a significant difference in the number of reactive nonstress tests and nonreactive nonstress tests between the 20- to 24-week, 24- to 28-week, 28- to 32-week, and 32- to 36-week gestational age groups. The increased incidence of nonreactive nonstress tests at earlier gestational ages may have clinical implications.     

早发型重度子痫前期发病孕周与母儿预后的关系

目的探讨早发型重度子痫前期的发病孕周与母儿预后的关系。方法回顾性分析2002年1月至2006年12月北京大学第一医院分娩的266例孕28-36周发病的单胎重度子痫前期患者的临床资料,按重度子痫前期发病孕周分为4组,Ⅰ组孕28-30周50例;Ⅱ组孕30^＋1-32周72例;Ⅲ组孕32^＋1-34周78例;Ⅳ组组孕34^＋1-36周66例。比较这4组的临床特点和母儿并发症。结果Ⅰ组孕妇有不良产史者明显高于Ⅱ组、Ⅲ组、Ⅳ组（32%vs 8.3%、5.1%、6.0%,P〈0.05）;Ⅰ组孕妇有子痫前期史者明显高于Ⅱ组、Ⅲ组、Ⅳ组（24%vs 5.5%、0%、9.0%,P〈0.05）;保守治疗时间Ⅰ组（19±23）d,Ⅱ组（10±10）d,分别明显高于Ⅲ组（6±9）d、Ⅳ组（5±7）d,（P〈0.05）;24 h尿蛋白定量平均为Ⅰ组（6.2±4.9）g,明显高于Ⅱ组（4.8±2.9）g、Ⅲ组（4.0±3.0）g、Ⅳ组（2.8±2.1）g,（P〈0.05）;围产儿死亡率Ⅰ组和Ⅱ组分别为48%、16.6%,明显高于Ⅲ组和Ⅳ组的5.1%、3.0%,P〈0.05;新生儿RDS的发生率Ⅰ组为24%、Ⅱ组为30.5%,分别明显高于Ⅲ组的2.5%、Ⅳ组的12.1%,P〈0.05;孕妇并发症各组之间分析比较差异无统计学意义。结论重度子痫前期发病孕周早晚和保守治疗时间长短与孕妇并发症的发生无关。孕32周之前发病的重度子痫前期的围产儿死亡率及新生儿RDS发生率明显高于孕32周之后发病者。孕妇的不良产史及子痫前期史与重度子痫前期的发病时间相关。     

Femur length versus biparietal diameter for estimating gestational age in the third trimester

It is well established that ultrasound measurement of femur length and biparietal diameter are comparably accurate estimators of gestational age when obtained in the first half of pregnancy. Both estimators, however, become less accurate later in pregnancy. The present study compares the relative accuracy of these estimators when obtained in the third trimester. It is concluded from linear regression analysis that the correlation between gestational age estimated from femur length and the actual gestational age is stronger than that between gestational age estimated from biparietal diameter and actual gestational age. Furthermore, gestational age calculated from femur length is significantly more likely to be within 2 weeks (P less than or equal to .01) and 3 weeks (P less than or equal to .05) of actual gestational age than is gestational age calculated from biparietal diameter. Estimating gestational age from the mean of the gestational age based on biparietal diameter and that based on femur length is less accurate than estimating gestational age from femur length alone.     

Correlation between self-reported gestational age and ultrasound measurements

BACKGROUND: We studied the agreement between different measurements of gestational age, i.e. self-reported gestational age in the Danish National Birth Cohort Study, ultrasound-estimated gestational age from the medical records in one Danish county and gestational age from the Danish National Hospital Discharge Register. METHODS: The ultrasound-estimated gestational length was based on the size of the biparietal diameter. The ultrasound-estimated gestational length was related to corrected and uncorrected last menstrual period estimates in the Danish National Cohort Study, and to the gestational length recorded in the Danish National Discharge Register. Non-parametric statistics were used in the analysis. RESULTS: The gestational ages estimated by ultrasound were 2-3 days shorter than gestational ages estimated by the other methods. The gestational ages recorded by the Discharge Register and the gestational ages based on corrected last menstrual period did not differ significantly. CONCLUSION: The self-reported gestational age in The Danish National Birth Cohort is in good concordance both with data from the National Hospital Discharge Register and with ultrasound-estimated gestational age.     

骨盆倾斜度与难产的关系

骨盆倾斜度异常是导致难产的一个原因 ,由于此类产妇骨盆外测量数值均正常 ,在头位难产中常被忽视。为提高分娩质量 ,减少难产的发生 ,我们通过在产程中改变产妇体位 ,纠正骨盆倾斜度 ,使胎头沿产轴方向下降而经阴道分娩 ,从而降低剖宫产率。1　资料与方法1 1　研究对象　 1994年 10月至 1999年 3月在我院住院分娩的产妇中 ,选择骨盆倾斜度≥ 70°的产妇 36 0例进行研究。36 0例随机分为两组 ,每组 180例。两组年龄均在 2 3～ 34岁 ,孕周 37～ 41周 ,均为单胎、头位 ,骨盆外测量正常 ,肛诊骨盆内测量无明显异常 ,无严重合并症及并发症[1] ,…     

Comparison of late-second-trimester nonstress test characteristics between small for gestational age and appropriate for gestational age infants

OBJECTIVE: To compare electronic fetal heart rate (FHR) monitoring characteristics between appropriate for gestational age (AGA) fetuses and small for gestational age (SGA) fetuses and to determine whether SGA fetuses have specific abnormalities at second-trimester electronic fetal monitoring (EFM), using nonstress test. METHODS: Among 953 children born from 1993-1996, we identified 500 singleton infants born after 36 weeks' gestation of uncomplicated pregnancies in whom second-trimester (24-27 weeks' gestation) EFM records were obtained. Individual components of FHR patterns (baseline rate, baseline FHR variability, presence of acceleration [at least 10 beats per minute for at least 10 seconds], and periodic or episodic deceleration [at least 25 beats per minute for at least 15 seconds]) and birth characteristics were compared between AGA and SGA infants, or between pregnancies with or without second-trimester decelerations. RESULTS: Among 500 infants, 443 were AGA and 57 SGA; 105 had and 395 did not have second-trimester decelerations. Baseline FHR variability (12.9+/-3.2 beats per minute) in SGA fetuses was significantly higher than variability (10.3+/-3.4 beats per minute) in AGA fetuses (P<.001). Small for gestational age fetuses were significantly more likely to have second-trimester decelerations than AGA fetuses (33.3% vs. 19.4%, P<.05). There were no significant differences in baseline rate and accelerations between AGA and SGA infants. Small for gestational age infants were more frequent in pregnancies with second-trimester decelerations, compared with those without second-trimester decelerations (18.1% vs. 9.6%, P<.05). Baseline FHR variability in pregnancies with second-trimester decelerations was significantly higher than in pregnancies without second-trimester decelerations (12.2+/-3.7 vs. 10.0+/-3.1 beats per minute, P<.001). CONCLUSION: Periodic or episodic decelerations and increased FHR variability during late second-trimester EFM were associated with an increased risk of SGA birth weight.     

不同糖耐量状态肥胖儿童血清脂联素的变化及其临床意义

目的了解不同葡萄糖耐量状态的肥胖儿童血清脂联素水平，探讨其与年 龄、体重指数(BMI)、血脂、血糖及胰岛素水平的关系。 方法选择2002~2004年于广州市儿童医院初诊并住院诊治的肥胖儿童52例，分为36例糖耐量正常(NGT)肥胖组和16例糖耐量受损(IGT)肥胖组。测定两组肥胖儿童和41例年龄、性别匹配的正常儿童空腹血清脂联素、胆固醇(CHO)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL C)、血糖和胰岛素(FINS)，计算胰岛素抵抗指数(HOMA IR)。肥胖组儿童均做口服葡萄糖耐量试验(OGTT)，测定OGTT 2h血糖和胰岛素。 结果正常对照组、NGT肥胖组及IGT肥胖组血清脂联素水平依次降低，HOMA IR依次升高，且均有统计学意义；相关性分析显示肥胖儿童血清脂联素与TG、LDL C、FINS呈显著负相关(P<005)。 结论肥胖儿童血清脂联素水平降低，并与血脂、胰岛素抵抗密切相关；与NGT肥胖组相比，IGT肥胖组儿童的血清脂联素水平进一步降低。     

Correlation between newborn gastric aspirate microviscosity and gestational age

Fluorescence polarization (FP) values were determined in 59 samples of amniotic fluid and in 56 samples of newborn gastric aspirate, collected from the 28th to 41st week of gestation. Both amniotic fluid and gastric aspirate FP values showed a significant correlation respectively with gestational age (r = 0.77; p less than 0.01 and r = 0.50; p less than 0.01). The two regression lines were parallel (F = 0.052; p = 0.8046). Mean FP of gastric aspirate were about 0.05 lower than those of amniotic fluid. One infant whose gastric aspirate FP value was 0.342 developed RDS.     

Fetal transcerebellar diameter measurement with particular emphasis in the third trimester: a reliable predictor of gestational age

OBJECTIVE: The purpose of this study was to validate prospectively a previous retrospectively established nomogram for the prediction of gestational age using transcerebellar diameter, especially in the third trimester. STUDY DESIGN: In a previous study, we retrospectively constructed a cross-sectional nomogram using transcerebellar diameter measurements in 24,026 well-dated singleton fetuses. In the present study, this nomogram was validated prospectively on the basis of patients who were seen between August 2002 and May 2003 and who were carrying non-anomalous and non-malformed singleton gestations between 14 and 42 weeks (n = 2597 gestations). The actual gestational age was then subtracted from the predicted gestational age, and the concordance between actual and predicted gestational ages was assessed based on the Pearson correlation (r). RESULTS: Concordance between the actual and predicted gestational age was high (r = 0.92; P < .0001). This agreement was superior in the second trimester (r = 0.93; P < .0001) than in the third trimester (r = 0.81; P < .001). Between 17 and 21 weeks, and between 22 and 28 weeks of gestation, the predicted gestational age ranged between 0 and 4 days, and between 0 and 2 days, respectively, of actual gestational age. Between 29 and 36 weeks of gestation, predicted gestational age was within 5 days of actual gestational age; at 37 weeks of gestation, the predicted gestational age was discrepant by 9 days. CONCLUSION: This prospective study demonstrates that transcerebellar diameter measurement is an accurate predictor of gestational age, even in the third trimester of pregnancy.     

Assessment of gestational age of the Asian fetus by the sonar measurement of crown-rump length and biparietal diameter

Summary. Two populations of pregnant Asian and European women were scanned using linear array real-time ultrasound machines. Measurements were made of fetal crown-rump length (CRL) up to 14 weeks gestational age and of biparietal diameter (BPD) up to 20 weeks gestational age. Polynomial growth curves relating CRL and BPD measurements to their gestational ages were fitted to the data by the method of unweighted least squares. There were no significant differences between the Asian and European parameters for the CRL and BPD curves. European nomograms may be used to establish Asian fetal gestational age up to 20 weeks.     

Oxytocinase activity in human amniotic fluid and its relationship to gestational age

Oxytocinase (EC 3.4.11.3) activity in amniotic fluid samples obtained from 200 normal pregnant women (mean age, 28 years) between 14 and 40 weeks of gestation and during active labor was assayed using S-benzyl-L-cysteine-p-nitroanilide (BCN) and L-leucine-p-nitroanilide (LN) separately as substrates. With both substrates, amniotic fluid oxytocinase activity correlated inversely with gestational age; the level of the enzyme, which was highest in early pregnancy, decreased exponentially to a minimum near term and during labor. However, whether oxytocinase activity in the amniotic fluid is of any significance for the maintenance and/or termination of pregnancy remains to be established.     

Fetal blood velocities in Rh isoimmunization: relationship to gestational age and to fetal hematocrit

Doppler blood cell velocities were measured in the aortas, inferior vena cavas, and umbilical veins of fetuses from isoimmunized pregnancies and related to the hematocrit levels of the fetal blood determined at fetoscopy. Pourcelot Index of flow in the umbilical artery was similarly studied. The mean velocities in the descending aortas and the Pourcelot Indexes of the umbilical arteries of both normal and affected fetuses correlated with fetal age. These velocities and indexes of affected fetuses also correlated inversely with the fetal hematocrit levels independently of the correlation with fetal age. The affected fetuses had higher mean velocities in the aorta and in the inferior vena cava than did normal fetuses. A simple model of multiple regression predicted the fetal hematocrit levels with a mean error of 3.8 hematocrit units (volume %).     

Mild gestational hypertension remote from term: progression and outcome

OBJECTIVE: Limited information is available regarding the progression of disease in women with mild gestational hypertension. Our purpose was to describe the prognostic signs in the natural course of mild gestational hypertension and pregnancy outcomes in women who were remote from term with mild gestational hypertension that was expectantly managed. STUDY DESIGN: Women with mild gestational hypertension participating in an outpatient hypertension monitoring program were studied. Inclusion criteria were patients with a singleton pregnancy between 24 and 35 weeks' gestation who had no proteinuria by dipstick (0 or trace) on the first 2 days of program participation. Progression to preeclampsia was the primary outcome. The rate of progression to severe preeclampsia, obstetric complications, and neonatal outcomes were secondary measures. Data were compared by independent Student t and Fisher exact tests where applicable. RESULTS: A total of 748 patients were studied during the observation period; preeclampsia (persistent proteinuria > or = 1+) developed in 343 (46%), and 72 (9.6%) had antepartum progression to severe preeclampsia. No significant differences in maternal age, race, marital status, or tobacco use were observed between those women in whom persistent proteinuria developed and those in whom it did not develop. Gestational age of the infants at delivery (36.5 +/- 2.4 vs 37.4 +/- 2.0 weeks), birth weight (2752 +/- 767 vs 3038 +/- 715 g), incidence of small-for-gestational-age newborns (24.8% vs 13.8%), and duration of neonatal hospital stay (7.1 +/- 10 vs 5.0 +/- 9.3 days) differed significantly in the patients with versus those without proteinuria (P <.001 for all). CONCLUSIONS: In patients with mild gestational hypertension remote from term, 46% ultimately had preeclampsia, with progression to severe disease in 9.6%. The development of proteinuria is associated with an earlier gestational age at delivery, lower birth weight, and an increased incidence of small-for-gestational age newborns.     

Serum unconjugated estriol levels in the third trimester and their relationship to gestational age.

Maternal unconjugated estriol levels were measured throughout the 28 to 41 week interval in two groups of accurately dated normal pregnancies. The first group consisted of randomly sampled pregnancies on which 285 unconjugated estriol determinations were performed. The logarithms of the mean values plotted into a positive sloping, relatively straight line which was disrupted by a plateau originating at 31 to 32 weeks and terminated at 35 weeks where there began a steep surge to a point at 36 weeks (surge point) that returned values to fit the previously established straight line. To investigate these findings in individual pregnancies, a second group of nine subjects was studied with serial unconjugated estriol determinations. In all nine of these subjects, the surge point could be identified statistically and occurred at a mean gestational age of 36.0 +/- 0.6 (1 S.D.) weeks. Data from the first group of randomly sampled pregnancies indicate that the surge point occurred around a mean gestational age of 36.0 weeks and was confirmed by data from the second group of serially sampled individual subjects showing the surge point as a statistically definable marker in normal pregnancies.