Longitudinal reference charts for growth of the fetal head, abdomen and femur

OBJECTIVES: The aims of the present study were to establish improved reference charts for growth of the fetal head, abdomen and femur, and to determine the effect of fetal and maternal factors. STUDY DESIGN: This prospective longitudinal study included 650 low-risk pregnancies. Outer-outer biparietal diameter (BPD), head circumference (HC), mean abdominal diameter (MAD), abdominal circumference (AC) and femur length (FL) were measured by ultrasound, and the statistical analysis was based on regression analysis and multilevel modeling. RESULTS: Reference percentiles for the growth of MAD, AC and FL showed continuous growth in gestational week 10-40, while BPD and HC showed a slightly blunted growth toward the end of pregnancy. FL was the only variable that was not influenced by gender. There was a significant negative association between breech presentation and all five biometrical variables, while maternal weight was positively associated with all five variables. Cephalic index significantly influenced BPD and HC. Maternal height had a positive effect on BPD, HC, AC and FL, and parity had a positive effect on MAD and AC, while smoking influenced negatively HC, MAD, and FL. Terms for calculating conditional reference values and customisation for individualised growth assessment are presented. CONCLUSIONS: New reference charts for the growth of fetal head, abdomen and femur are suggested for assessing fetal size and growth, and can be adjusted for maternal and fetal factors to suite individual pregnancies.     

Fetal age assessment based on ultrasound head biometry and the effect of maternal and fetal factors

BACKGROUND: Maternal height and weight have increased during the past 20 years, as has birthweight. The aim of the present study was to establish new reference charts for gestational age (GA) assessment using fetal biparietal diameter (BPD) and head circumference (HC), and to determine the effect of maternal and fetal factors on age assessment. METHODS: This was a prospective, cross-sectional study of 650 healthy women with regular menstrual periods and singleton uncomplicated pregnancies, recruited after written consent. BPD (outer-outer) and HC were measured at 10-24 weeks of gestation. We used regression analysis to construct mean curves and assess the effect of maternal and fetal factors on age assessment. RESULTS: BPD and HC were successfully measured in 642 participants. Using BPD and HC before 20 weeks, the new charts gave 3-8 days higher GA assessment than the charts presently in use, and <1 day difference compared to other recently established charts. Maternal age, multiparity, fetal gender, breech position and shape of fetal head affect GA estimation by 1-2 days when using BPD (p = 0.0001-0.02). Only maternal age and fetal gender affected GA estimation when using HC (相似文献   

The effect of fetal sex on customized fetal growth charts

Objective: To evaluate the effect of fetal sex on singleton pregnancy growth charts customized for parental characteristics, race, and parity

Methods: In a multicentric cross-sectional study, 8070 ultrasonographic examinations from low-risk singleton pregnancies between 16 and 40 weeks of gestation were considered. The fetal measurements obtained were biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL). Quantile regression was used to examine the impact of fetal sex across the biometric percentiles of the fetal measurements considered together with parents’ height, weight, parity, and race.

Results: Fetal gender resulted to be a significant covariate for BDP, HC, and AC with higher values for male fetuses (p?≤?0.0009). Minimal differences were found among sexes for FL. Parity, maternal race, paternal height and maternal height, and weight resulted significantly related to the fetal biometric parameters considered independently from fetal gender.

Conclusion: In this study, we constructed customized biometric growth charts for fetal sex, parental, and obstetrical characteristics using quantile regression. The use of gender-specific charts offers the advantage to define individualized normal ranges of fetal biometric parameters at each specific centile. This approach may improve the antenatal identification of abnormal fetal growth.     

Value of a single early third trimester fetal biometry for the prediction of birth weight deviations in a low risk population

OBJECTIVE: To analyze the value of a single ultrasound biometry examination at the onset of the third trimester of pregnancy for the detection of small-for-gestational-age (SGA) and large-for-gestational-age (LGA) at birth in a low risk population. The aim of this study was to develop a simple and useful method for the detection of growth deviations during pregnancy in primary care (midwife or general practitioner) practices. SETTING: A Dutch primary care midwifery practice. STUDY DESIGN: In an earlier study, we developed parity and sex specific fetal growth charts of abdominal circumference (AC) and head circumference (HC) on the basis of ultrasound data of a low-risk midwifery population in the Netherlands. In the present study, we calculated sensitivity, specificity and predictive values at different cut-off points of AC and HC for the prediction of growth deviations at birth. Patients booked for perinatal care between 1 January 1993 and 31 December 2003 (n=3449) were used for the identification of cut-off points (derivation cohort) and those admitted between 1 January 2004 and 31 December 2005 (n=725) were used to evaluate the performance of these cut-offs in an independent population (validation cohort). For the determination of SGA and macrosomia at birth, we used the recently published Dutch birth weight percentiles. RESULTS: Most promising cut-offs were AC or=75(th) percentile for the prediction of macrosomia (birth weight >or=90(th) percentile). Within the validation cohort these cut-offs performed slightly better than in the derivation cohort. For the prediction of SGA, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 53% (95% CI 49-58%), 81% (95% CI 80-83%), 26% (95% CI 23-29%), and 93% (95% CI 93-94%), respectively. The false positive rate was 74%. For the prediction of macrosomia, the values of these parameters were 64% (95% CI 59-69%), 80% (95% CI 78-81%), 23% (95% CI 20-26%), and 96% (95% CI 95-97%), respectively. Here, false positive rate was 77%. No cut-offs were found that predicted extreme birth weight deviations (or=97.7 percentile) sufficiently well. CONCLUSIONS: In a low risk population, we could predict future growth deviations with a higher sensitivity and in a significant earlier stage (at the onset of the third trimester of pregnancy) than with the use of conventional screening methods (i.e., palpation of the uterus only and fundus-symphysis measurement). Sonographic measurement of fetal abdominal circumference enables to detect more than half of cases of SGA at birth and more than two-thirds of cases of macrosomia with acceptable false-positive rates. We suggest that fetuses with biometry results below the 25(th) percentile or above the 75(th) percentile at the onset of the third trimester of pregnancy should be more intensively investigated in order to distinguish between pathology (e.g., IUGR or macrosomia) and physiology and to decide about the appropriate level of further perinatal care.     

First-trimester screening for fetal triploidy at 11 to 14 weeks: a role for fetal biometry

OBJECTIVE: Intrauterine growth restriction in triploidy has been reported as early as in the first trimester. This study was undertaken to evaluate the ability of first-trimester crown rump length (CRL)-based charts to detect triploid fetuses. MATERIAL AND METHODS: Analysis of fetal biometry in cases of triploidy diagnosed in the first trimester over the last three years. Biometry for abdominal circumference (AC), head circumference (HC) and biparietal diameter (BPD) was analyzed in relation to both gestational age (GA)-based charts and to CRL-based charts. RESULTS: Five cases of fetal triploidy were diagnosed at 11 to 14 weeks. Screening based on nuchal translucency (NT) and maternal age showed a risk > 1/300 in only one of the 5 cases of triploid fetus. In all of these five cases, CRL-based biometry was grossly abnormal, although it was abnormal in only two of these five cases in relation to GA-based charts. CONCLUSION: First-trimester CRL-based biometry charts seem to reflect early asymmetrical growth delay in triploidy more accurately than GA-based charts. CRL-based biometry is likely to improve the early detection of triploid pregnancies without leading to dating error.     

Fetal age assessment based on femur length at 10-25 weeks of gestation, and reference ranges for femur length to head circumference ratios

BACKGROUND: The aim of the present study is to establish new reference charts for gestational age assessment based on fetal femur length (FL), and new reference ranges for FL to head ratios at gestational weeks 10-25, and to determine the effect of maternal and fetal factors on these charts. METHODS: Six hundred fifty low-risk women with regular menstrual periods and singleton pregnancies were recruited to a prospective cross-sectional study after obtaining written consent. FL, outer-outer biparietal diameter (BPD), and head circumference (HC) were measured at 10-25 weeks of gestation. We used regression analysis in order to construct mean curves and to assess the effect of maternal and fetal factors on age assessment. RESULTS: The new chart for age assessment by means of FL was based on 636 measurements. The 95% CI of the mean corresponded to <1 day. The variation between the mean and the 90th percentile was 5, 6, and 7 days at 13, 18, and 23 weeks, respectively, similar to the results when using BPD or HC. Maternal age modestly influenced gestational age assessment (1.3 days/10 years, P = 0.005), whereas smoking, height, body mass index, multiparity, fetal sex, cephalic index, and breech presentation had no impact. Reference charts for FL to head ratios have been presented. Maternal age, fetal sex, and cephalic index influenced the FL/BPD ratio, whereas only fetal sex influenced FL/HC. CONCLUSIONS: Fetal age assessment based on FL is an equally robust method as using HC. FL/HC is a more robust ratio to characterize fetal proportions than is FL/BPD.     

Evaluation of fetal sonographic measurements in the first trimester by transvaginal sonography.

To assess the reliability of early biometric measurements in pregnancy, transvaginal sonography was performed in 92 pregnancies in the first trimester in a cross-sectional fashion. Measurements included crown-to-rump length (CRL), biparietal diameter (BPD), head and abdominal circumference (HC and AC), and femur length (FL). Stepwise regression analysis of the gestational age was performed. CRL maintained the highest correlation with gestational age (r = 0.99, p less than 0.001). BPD, HC, AC also correlated well. FL showed a less strong correlation with gestational age (r = 0.76, p less than 0.001). CRL remains the standard for early sonography measurements.     

Differences in amniotic fluid patterns and fetal biometric parameters in third trimester pregnancies with and without diabetes.

OBJECTIVE: The amniotic fluid index (AFI) has been increasingly used in the assessment of fetal well-being. We conducted the study to evaluate and compare the amniotic fluid index in third trimester normal and diabetic human pregnancy and to assess the correlation between the AFI and the fetal biometric parameters. METHODS: Real-time ultrasound was performed to evaluate the AFI (four-quadrant technique), and to measure the biparietal diameter, head circumference, abdominal circumference, and femur length in 225 normal and 120 diabetic pregnant women from 27 to 42 weeks of gestation. Each patient was studied only once. RESULTS: AFI in normal pregnancies was less than that in diabetic pregnancies throughout the gestational ages studied (27-42 weeks). In normal pregnancy, the mean AFI was 14.0 cm at 27 weeks and decreased to 11.4 cm at 42 weeks (r = 0.25, p = 0.0005), whereas in diabetic pregnancies, the values remained stable throughout the gestational ages studied. There exist significant differences in AFI, estimated fetal weight, estimated fetal weight %, abdominal circumference, abdominal circumference %, and head circumference to abdominal circumference ratio between the two groups. In both normal and diabetic pregnancies, there is a positive correlation between the AFI and the percentile of abdominal circumference (p < 0.0001), and between the AFI and the percentile of estimated fetal weight (p < 0.0001). CONCLUSION: This study provides gestational age-specific values of the AFI in normal and diabetic pregnancies. Diabetic pregnancy has greater AFI values than normal pregnancy between 27 and 42 weeks. The AFI correlates to the percentile of the estimated fetal weight and the abdominal circumference in both groups, suggesting that there may be a relationship between increased AFI and large for gestational age fetus independent of diabetes.     

Antenatal care in The Gambia: Missed opportunity for information, education and communication

Background

Conventionally, the pregnancy duration is accepted to be 280–282 days. Fetuses determined by ultrasound biometry to be small in early pregnancy, have an increased risk of premature birth. We speculate that the higher rate of preterm delivery in such small fetuses represents a pathological outcome not applicable to physiological pregnancies. Here we test the hypothesis that in low-risk pregnancies fetal growth (expressed by fetal size in the second trimester) is itself a determinant for pregnancy duration with the slower growing fetuses having a longer pregnancy.

Methods

We analysed duration of gestation data for 541 women who had a spontaneous delivery having previously been recruited to a cross-sectional study of 650 low-risk pregnancies. All had a regular menses and a known date of their last menstrual period (LMP). Subjects were examined using ultrasound to determine fetal head circumference (HC), abdominal circumference (AC) and femur length (FL) at 10–24 weeks of gestation. Length of the pregnancy was calculated from LMP, and birth weights were noted. The effect of fetal size at 10–24 weeks of gestation on pregnancy duration was assessed also when adjusting for the difference between LMP and ultrasound based fetal age.

Results

Small fetuses (z-score -2.5) at second trimester ultrasound scan had lower birth weights (p < 0.0001) and longer duration of pregnancy (p < 0.0001) than large fetuses (z-score +2.5): 289.6 days (95%CI 288.0 to 291.1) vs. 276.1 (95%CI 273.6 to 278.4) for HC, 289.0 days (95%CI 287.4 to 290.6) vs. 276.9 days (95%CI 274.4 to 279.2) for AC and 288.3 vs. 277.9 days (95%CI 275.6 to 280.1) for FL. Controlling for the difference between LMP and ultrasound dating (using HC measurement), the effect of fetal size on pregnancy length was reduced to half but was still present for AC and FL (comparing z-score -2.5 with +2.5, 286.6 vs. 280.2 days, p = 0.004, and 286.0 vs. 280.9, p = 0.008, respectively).

Conclusion

Fetal size in the second trimester is a determinant of birth weight and pregnancy duration, small fetuses having lower birth weights and longer pregnancies (up to 13 days compared with large fetuses). Our results support a concept of individually assigned pregnancy duration according to growth rates rather than imposing a standard of 280–282 days on all pregnancies.     

Comparison of customized and cohort-based birthweight standards in identification of growth-restricted infants in GUSTO cohort study

Background: The aim was to evaluate the ability of customized and cohort birthweight standards in discriminating intrauterine growth retardation (IUGR).

Methods: Birthweights (BWs) of GUSTO singleton infants born at gestational age (GA) 35–41 weeks were converted using two standards: (a) GUSTO cohort-based BW centile adjusted for GA and baby gender; (b) customized BW percentile calculator adjusted for maternal height and weight, race, parity, GA and gender. Infants were classified into three groups: (1)?<?10th BW centile by customization– customized-SGA, (2)?<?10th BW centile by GUSTO– GUSTO-SGA; and (3)?>?10th BW centile by both standards – BOTH-non-SGA.

Results: Of the 1011 infant–mother dyads, 68 were customized-SGA and 104 were GUSTO-SGA, with concordance of 61% (n?= 63) for SGA. While 5 (7%) of customized-SGA were not SGA by GUSTO-charts, 41 (39%) of GUSTO-SGA were not SGA by customized-charts. Customized-SGA had significantly the least growth in abdominal circumference (AC) and highest head circumference (HC): AC growth ratio between second and third trimester; and the lowest mean BW, ponderal index and placental weight than other groups.

Conclusion: Customized-SGA standard was a better discriminator of pathologic fetal growth based on AC growth. It improved strength of association with pathology and in our population reduced false positives (41/104?=?39%) in the assessment of SGA.     

Reference charts and equations of Korean fetal biometry

OBJECTIVE: To construct new reference charts and equations for fetal biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur diaphysis length (FDL) from Korean fetuses at 12-40 weeks. METHOD: Prospective cross-sectional data obtained in one center for 5 years from a population of pregnant women undergoing ultrasound examination between the 12th and 40th week of gestation. Exclusion criteria comprised all maternal and fetal conditions possibly affecting fetal biometry. No fetuses were excluded on the basis of abnormal biometry. For each measurement, regression models were fitted to estimate both the mean and the standard deviation at each menstrual age. RESULTS: Biometric measurements were obtained for 10 455 fetuses. New charts and reference equations are reported for BPD, HC, AC and FDL. Reference equations are cubic models. CONCLUSION: We present new Korean reference charts and equations for fetal biometry. They can be easily used in obstetric ultrasound studies for the Korean population.     

Co-variables in first trimester maternal serum screening

The objective of this study was to determined the influence of maternal weight, maternal smoking habits, gravidity, parity and fetal gender on the level of maternal serum marker used in first trimester screening for Down syndrome. A total of 2449 singleton unaffected pregnancies from two centres were studied. Maternal serum free beta-human chorionic gonadotrophin (hCG) and alpha-fetoprotein (AFP) concentrations had been measured in all pregnancies, and pregnancy associated plasma protein (PAPP)-A levels had been measured in 924. All results were expressed as multiples of the gestation specific median (MoM) values after regression, using each centre's own medians. Information on maternal weight was available in 2259 pregnancies, on self-reported current cigarette smoking in 1364 (of whom 117 (8.6%) were smokers), on gravidity in 1371, parity in 1303 and fetal gender in 253. All three markers showed a statistically significant negative association with maternal weight (p<0.0005) and in the subsequent analyses MoM values were weight adjusted using standard methods. The median PAPP-A level in smokers was 0.81 MoM, a significant reduction (p<0.005); free beta-hCG was also reduced (median 0.89 MoM) but not significantly (p=0.17), and AFP was unaltered. The median AFP level in primagravidas was highly significantly greater than that in gravid women (p<0.0005). In PAPP-A the reverse effect was seen but it did not reach statistical significance (p=0.15) and there was no effect for free beta-hCG. Results of a similar magnitude and direction were found for parity. The median level of free beta-hCG was higher (p=0.0005), and the median AFP lower in female pregnancies. Maternal weight and, for PAPP-A, maternal smoking are important first trimester screening co-variables. Gravidity, parity and fetal gender also seem to influence one or more first trimester markers.     

Can discordance in CRL at the first trimester predict birth weight discordance in twin pregnancies?

Abstract Objective: To examine the correlation between measurements of crown rump length (CRL), nuchal translucency (NT), and birth weight in dichorionic (DC) and monochorionic (MC) twin pregnancies. Methods: A retrospective analysis was performed on all twin term pregnancies delivered between 2001 and 2007 at the McGill University Health Center. Data collected included maternal age, CRL and NT measurement, results of glucose challenge test, birth weight and length, gestational age at delivery, and fetal gender. Results: The study population comprised 792 fetuses: 94 MC/DA and 698 DC/DA. Maternal age, gestational age at delivery, birth weight, and birth length were all significantly higher for the DC group. Male fetuses had significantly higher NT and higher birth weight than female fetuses. Discordance in CRL was found to correlate with discordance in birth weight in the entire study population (P<0.0001, R=0.25), in the DC twins (P<0.0001, R=0.275), but not in MC twins (R=0.10, P=0.33). CRL discordance above the 90th percentile (>12%) predicted 14/40 pregnancies with birth weight discordance above the 90th percentile (>24%) [P<0.001, LR=4.1 (2.6-6.2)]. CRL discordance above the 95th percentile (>16%) predicted 5/21 pregnancies with birth weight discordance above the 95th percentile (>30%) [P<0.001, LR=5.5 (2.6-10.4)]. NT discordance was correlated with CRL discordance (R=0.15, P<0.0001), but not with birth weight, regardless of chorionicity or gender. Conclusion: In twin pregnancies, CRL discordance in first trimester can predict discordance of more than 25% in neonatal birth weight.     

Neck Circumference Measurements in Second Trimester Fetuses with Down's Syndrome

Ultrasound examinations were performed on 132 normal fetuses between 12 and 25 weeks of gestation to measure the fetal neck circumference (NC), biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL). The relationships between the fetal neck circumference and gestational age, as well as between the fetal neck circumference and fetal biometric parameters (BPD, HC, AC, FL) were linear. Nomograms between the fetal neck circumference and all other parameters were established including the 5th, 50th, and 95th percentile lines. Only one of nine fetuses with Down's syndrome was found to have abnormally increased fetal neck circumference (above the 95th percentile), whereas the remaining eight cases were equally distributed above and below the 50th percentile of these nomograms. The positive predictive value of an abnormally increased fetal neck circumference was 1.6% in our tested population, where the prevalence of Down's syndrome was 1 in 132. Our observations suggest that the use of fetal neck circumference in second trimester fetuses does not add in the prenatal diagnosis of Down's syndrome.     

Gender-related differences in fetal heart rate during first trimester

OBJECTIVE: Many expecting parents wish to ascertain fetal gender early in pregnancy. Our goal was to determine whether fetal heart rate (FHR) of males and females during the first trimester is significantly different. MATERIALS AND METHODS: From November 1997 to February 2003 we enrolled pregnant women with singleton gestations who underwent obstetric sonography at less than 14 weeks of gestational age. Indications for the sonographic study included first-trimester bleeding, uncertain gestational dating, poor obstetrical history, and aneuploidy screening by nuchal translucency. The sonographic studies were performed by a single sonographer and reviewed by the first author. The FHR was determined by m-mode. All subjects underwent second-trimester sonography at 18.0-24.0 weeks' gestation by the same team, and fetal gender was recorded. Multiple gestations, miscarriages and pregnancies with uncertain fetal gender were excluded. Sonographically assigned fetal gender was confirmed at delivery. RESULTS: Of the 966 first-trimester studies performed, 477 met the inclusion criteria. Of these, 244 (51%) were female and 233 (49%) were males. There were no statistical differences in mean maternal age, gravidity, parity, and mean gestational age at the time of the first study (9.0 +/- 2.3 weeks for female fetuses and 9.0 +/- 2.3 weeks for males, p = 0.7). The average female FHR was 151.7 +/- 22.7 bpm and male FHR was154.9 +/- 22.8 bpm (p = 0.13). DISCUSSION: Contrary to beliefs commonly held by many pregnant women and their families, there are no significant differences between male and female FHR during the first trimester.     

Ultrasound biometry of Arabian fetuses.

OBJECTIVE: To establish fetal ultrasound biometry charts for Arabian fetuses between 14 and 40 weeks of gestation. METHOD: Cross-sectional fetal ultrasound data of normal singleton pregnancies, which had been performed over a period of 7 years, were retrieved. Only pregnant Arab women with certain last menstrual period dates and/or early ultrasound examinations were included. Each fetus contributed to only one set of data. Normal ranges for biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL) were established. The mean and 5th and 95th percentiles at 18th, 28th, and 36 weeks of gestation were compared with similar ranges of published data from pregnancies of American and Anglo-Saxon population. RESULTS: Fetal ultrasound biometry has been established for our local population. Comparing our data with Western population emphasizes the presence of significant variation in fetal morphometric measurements, particularly in the later weeks of gestation and at the extremes of the range of fetal size. CONCLUSION: The clinical significance of this variation differs according to the primary objective of ultrasound fetal measurements. For estimation of fetal age, usually by head and femur measurements in early gestation, ethnic variation seems to have limited significance. Whereas for estimation of fetal growth and/or weight in the third trimester, based on abdominal circumference, the use of given points, e.g., 10th or 5th percentile derived from other population charts, has the potential of either over- or underdiagnosis of IUGR fetuses. The adoption of locally developed charts is recommended.     

Differences in amniotic fluid patterns and fetal biometric parameters in third trimester pregnancies with and without diabetes

Objective.?The amniotic fluid index (AFI) has been increasingly used in the assessment of fetal well-being. We conducted the study to evaluate and compare the amniotic fluid index in third trimester normal and diabetic human pregnancy and to assess the correlation between the AFI and the fetal biometric parameters.

Methods.?Real-time ultrasound was performed to evaluate the AFI (four-quadrant technique), and to measure the biparietal diameter, head circumference, abdominal circumference, and femur length in 225 normal and 120 diabetic pregnant women from 27 to 42 weeks of gestation. Each patient was studied only once.

Results.?AFI in normal pregnancies was less than that in diabetic pregnancies throughout the gestational ages studied (27–42 weeks). In normal pregnancy, the mean AFI was 14.0 cm at 27 weeks and decreased to 11.4 cm at 42 weeks (r = 0.25, p = 0.0005), whereas in diabetic pregnancies, the values remained stable throughout the gestational ages studied. There exist significant differences in AFI, estimated fetal weight, estimated fetal weight %, abdominal circumference, abdominal circumference %, and head circumference to abdominal circumference ratio between the two groups. In both normal and diabetic pregnancies, there is a positive correlation between the AFI and the percentile of abdominal circumference (p < 0.0001), and between the AFI and the percentile of estimated fetal weight (p < 0.0001).

Conclusion.?This study provides gestational age-specific values of the AFI in normal and diabetic pregnancies. Diabetic pregnancy has greater AFI values than normal pregnancy between 27 and 42 weeks. The AFI correlates to the percentile of the estimated fetal weight and the abdominal circumference in both groups, suggesting that there may be a relationship between increased AFI and large for gestational age fetus independent of diabetes.     

Normal standards for fetal neurobehavioral developments--longitudinal quantification by four-dimensional sonography

AIM: To construct normal standards for fetal neurobehavioral development using longitudinal observations through all trimesters by four-dimensional sonography. SUBJECT AND METHODS: A group of 100 healthy normal singleton pregnancies were recruited for longitudinal 4D US examinations to evaluate fetal neurodevelopmental parameters between 7 to 40 weeks' gestation. Variables of maternal and fetal characteristics including gestational age, eight fetal movements patterns in the first trimester and 14 parameters of fetal movement and fetal facial expression patterns recorded thereafter for the construction of fetal neurological charts. RESULTS: Measurement of 7 parameters in the first trimester and 11 parameters in the second and third trimesters correlated with gestational age (P<0.05). Those parameters have been followed longitudinally through all trimesters and showed increasing frequency of fetal movements during the first trimester. A tendency towards decreased frequency of facial expressions and movement patterns with increasing gestational age from second to third trimesters has been noticed. CONCLUSION: With 4D sonography, it is possible to quantitatively assess normal neurobehavioral development. There is urgent need for further multicentric studies until a sufficient degree of normative data is available and the predictive validity of the specific relationship between fetal neurobehavior and child developmental outcome is better established.     

孕晚期营养素摄入与B超下胎儿各生长指标的关系

目的:探讨妊娠晚期孕妇不同营养素摄入量与B超下胎儿各部位测量值的关系。方法:对799例无妊娠合并症及并发症的健康孕妇进行前瞻性营养调查,在妊娠32、34、36周调查3天。用食物日志形式记录3天摄入食物的种类及重量。将食物摄入量转换成营养素摄入量。于妊娠28周及38周左右行两次B超检查,测量胎儿双顶径、头围、腹围、股骨及肱骨长度,并用两次测量之差值反映胎儿孕晚期的生长情况。采用多元线性回归分析孕晚期营养与胎儿生长的关系。结果:孕晚期脂肪供能比与胎儿腹围、头围和股骨增长有关,脂肪供能比每增加1%,胎儿腹围增加2.27mm(P=0.023),胎儿头围增加3.86mm(P=0.01),胎儿股骨长度增加1.35mm(P=0.04)。钙的摄入量与胎儿股骨增长有关;锌、维生素B1、、B2及维生素E与胎儿双顶径关系密切。结论:脂肪供能比与胎儿多个生长指标密切相关,是影响胎儿出生体重的重要因素。不同的营养素对B超测量的胎儿生长指标的影响不完全相同的。