Predicting late-onset growth abnormalities using growth velocity between trimesters.

OBJECTIVES: To determine whether growth velocity parameters derived from routine prenatal ultrasound measurements at first, second and third trimester can identify normal growth at term as well as late-onset growth abnormalities. MATERIAL AND METHODS: Longitudinal study of fetal growth in normal singleton pregnancies with three normal ultrasound examinations and delivered at term. Fetuses were classified into 3 groups (<10th percentile, 10-90th percentile, >90th percentile) based on birth weight. Multiple regression on birth weight classification was used to build up a prediction equation of fetal growth potential (FGP) based on fetal biometry and fetal growth velocity parameters between ultrasound examinations. Best cut-off value for FGP predicting growth restriction and macrosomia were defined. RESULTS: 356 pregnancies were included. Fetal biometry growth velocities between examinations were calculated for all measurements. Using best cut-off values, the estimated sensitivity, specificity and odds ratio were: 60% [44;74], 91% [89;92] and 14.55 [6.30;33.98] and 53% [36;69], 89% [88;91] and 10 [4.27;23.49] for the prediction of growth restriction and macrosomia, respectively. DISCUSSION: Fetal growth potential can be derived and calculated from standard ultrasound measurements. It can improve identification of these fetuses at risk for late-onset growth abnormalities and their related morbidity.     

Morphometric placental villous and vascular abnormalities in early- and late-onset pre-eclampsia with and without fetal growth restriction

OBJECTIVE: To evaluate placental morphology in pregnancies complicated by early- and late-onset pre-eclampsia (PET) with and without fetal growth restriction (FGR) using stereological techniques. DESIGN: A total of 69 pregnant women were studied. Twenty women had pregnancies complicated by PET, 17 by FGR and 16 by both PET and FUR; the remaining 16 were from gestational-age-matched controls. Each group was further classified into early onset (<34 weeks) and late onsets (>34 weeks) based on gestational ages. SETTING: NPIMR at Northwick Park and St Marks Hospital. POPULATION: placentae from pregnant women. METHODS: Formalin-fixed, wax-embedded sections stained with anti-CD34 antibodies and counterstained with haematoxylin. MAIN OUTCOME MEASURES: Volumes, surface areas, lengths, diameters and shape factors of the villous tissues and fetal vasculature in the intermediate and terminal villi of all the groups studied. RESULTS: Terminal villi volume and surface area were compromised in early-onset PET cases, late-onset PET had no impact on peripheral villi or vasculature features. The morphology of the vascular and villous subcomponents in the intermediate and terminal villi was significantly influenced by late-onset FGR, whereas early-onset FGR caused a reduction in placental weight. Length estimates were not influenced by PET, FGR or age of onset. Intermediate arteriole shape factor was significantly reduced in late-onset FGR. CONCLUSIONS: Isolated early-onset PET was associated with abnormal placental morphology, but placentas from late-onset PET were morphologically similar to placentas from gestational-age-matched controls, confirming the existence of two subsets of this condition and supporting the hypothesis that late-onset PET is a maternal disorder and not a placental disease.     

Fetal biometry and fetal weight estimation: JSUM standardization

From the clinical point of view, it is very important to standardize methods of fetal growth evaluation. The standardization committee of fetal measurement of the Japanese Society of Ultrasound in Medicine (JSUM) announced the recommended standard procedure for fetal biometry, calculation of estimated fetal weight (EFW) and their evaluation method. In short, the abdominal circumference (AC) by the ellipse-tracing method should be the standard for the fetal abdominal measurement and the EFW should be calculated by the following formula:

EFW = 1.07 × BPD. + 0.30 × AC × FL,

where BPD is the biparietal diameter and FL the femur length.     

孕期不同阶段增重与新生儿出生体重的相关性

目的:探讨正常足月孕妇孕期不同阶段增重与新生儿出生体重的关系。方法:回顾分析2014年1月至2014年12月在嵊州人民医院定期产前检查并且正常足月单胎孕妇2634例的临床资料。根据孕前体重指数(BMI)分为3组:低体重组(18.5kg/m2),正常体重组(18.5~23.9kg/m2),超重组(24~27.9kg/m2)。收集孕妇早、中、晚孕期的体重增加值,分析孕期不同阶段增重与新生儿出生体重的关系。结果:低体重组、正常体重组和超重组孕期增重分别为15.0kg(12.7,17.7kg)、14.5kg(12.0,17.5kg)和13.0kg(9.0,16.0kg);新生儿出生体重分别为3230g(3000,3470g)、3330g(3090,3600g)和3437g(3140,3722g),3组比较差异均有统计学意义(P0.05)。低体重组、正常体重组和超重组早孕期增重分别为1.4kg(0.6,2.3kg)、1.1kg(0.6,2.1kg)和1.1kg(0.4,1.9kg);中孕期增重分别为7.8kg(6.5,9.4)kg、7.5kg(6.0,9.0kg)和6.5kg(4.8,8.1kg);晚孕期增重分别为5.8kg(4.2,7.5kg)、5.7kg(4.2,7.4kg)和5.1kg(3.5,7.0kg);同孕期3组比较,差异均有统计学意义(P0.05)。回归结果表明,除低体重组晚孕期和超重组早孕期以外,其余各孕期体重增加对新生儿出生体重均有促进作用。其中低体重组早孕期增重对新生儿体重增加影响最大(标准化回归系数0.21,P0.05);正常体重组和超重组中孕期增重对新生儿体重增加影响最大(标准化回归系数分别为0.18,0.10,P均0.05)。含哑变量的回归结果示,对整个研究群体而言,中孕期增重对出生体重的影响最大(标准化回归系数0.18,P0.05);相对于正常体重组早孕期增重对新生儿出生体重增加的影响而言,低体重组孕早期增重影响更大(标准化回归系数差为0.05,P0.05),而超重组最小(标准化回归系数差为-0.06,P0.05)。结论:孕前BMI和孕期不同阶段增重与新生儿出生体重有关;低体重组早孕期增重对新生儿出生体重增加影响最明显,而正常体重组和超重组则中孕期增重对新生儿体重增加最明显。因此,根据孕前BMI制定孕期不同阶段合理增重对于控制新生儿体重具有指导意义。     

Divergence of estimated fetal weight and birth weight in singleton fetuses

Objective: To evaluate differences in distribution of estimated fetal weight (EFW) and birth weight (BW) of ongoing fetuses and neonates of the same gestational age.

Methods: Reference curves for EFW (Hadlock BPD-HC-AC-FL formula, N?=?1191) and BW (N?=?1036) in singleton pregnancies from 24⁺⁰ to 40⁺⁶ gestational weeks were calculated. Multiple pregnancies, fetuses with major or multiple abnormalities or syndromes and iatrogenic preterm deliveries due to preeclampsia or abnormal fetal Doppler were excluded. The standardized residuals for EFW and BW were calculated and compared.

Results: EFW and BW can be accurately described by quadratic equations (R²?=?0.944 and 0.807, respectively). The distribution of standardized residuals for BW using the EFW formula was negative from 28⁺⁰ to 35⁺⁶ weeks. The 50th and 5th centiles of BW were lower than those of EFW throughout prematurity, and they converged at approximately 38 gestational weeks. The 5th centile for BW was 30% lower than the 5th centile for EFW at 27 weeks, 27.5% lower at 30 weeks and 19.4% at 34 weeks.

Conclusions: Preterm infants have lower BW distribution compared to the expected EFW of ongoing pregnancies of the same gestational age, supporting the concept of hidden intrauterine morbidity for a proportion of these infants.     

Ultrasonic estimation of fetal weight at term: an evaluation of eight formulae

AIM: To compare the accuracy of eight sonographic formulae for predicting fetal birth weight at term in a multiethnic population. METHODS: Pregnant women at term who were booked for induction of labor or elective cesarean section were included in the study. Eight ultrasonic fetal biometric formulae were used to predict fetal birth weight. RESULTS: A total of 173 patients were included in the study; 53 (30.6%) patients were from the Indian subcontinent, 44 (25.4%) patients were from Africa, 33 (19.1%) patients were from the Arabian Peninsula and 43 (24.9%) were from other ethnic groups. The mean absolute error ranged from a minimum of 0.3% (+/-11.3) for Hadlock (biparietal diameter [BPD], head circumference [HC], abdominal circumference [AC], femur length [FL]) to a maximum of 37.5% (+/-10.0) for Warsof (FL). The correlation of estimated fetal weight with actual birth weight ranged from a minimum of 0.09 with Warsof (FL) to a maximum of 0.77 with Shepard and Warsof (BPD, AC) and Hadlock (BPD, HC, AC, FL). The combination of AC with BPD measurements rather than FL achieves a high level of accuracy. CONCLUSIONS: Shepard (BPD, AC) provides a simple and accurate logarithm for the prediction of fetal weight at term in the studied multiethnic population.     

Specific formulas improve the estimation of fetal weight by ultrasound scan

Abstract

Objective: To develop and evaluate local, sex specific, small for gestational age (SGA) specific, large for gestational age (LGA) specific and combined (biometry, sex and Doppler indices) formulas for ultrasound estimated fetal weight (EFW).

Method: Low-risk singleton pregnancies that delivered within 7 days from ultrasound examination were assessed. A formula-generating group (1407 pregnancies) and a validation group (469 pregnancies) were created. Fractional regression analysis was used to develop the formulas. Systematic error, random error, fraction within the 10% of actual birth weight and Bland–Altman analysis were used.

Results: The local formula and the Hadlock formula with local co-efficients performed better than the Hadlock formula. The SGA-specific formula, the LGA-specific formula and the combined formula had the lower systematic error (MSE: +0.0022291, ?0.4226888, +0.8386222, respectively) and the narrower 95% LOA (?292.8 to +292.23, ?485.6 to +461.5, ?425.7 to +450.46, respectively). The SGA- and the LGA-specific formulas had higher fraction within the 10% of actual birth weight (81.5% and 84%, respectively).

Conclusions: Local formulas improve the EFW calculation. The combined formula can further optimize the accuracy and precision. Application of specific formulas for the small and the large fetus had the most pronounced effect in improving fetal weight estimation.     

影响极低出生体重儿早期生长赶超的原因

目的 分析极低出生体重儿（very low birth weight infant，VLBWI）在纠正胎龄40周时的生长赶超情况及影响因素。方法 以50例VLBWI作为研究对象。以40周胎龄健康足月儿和15个城市不同胎龄婴儿出生体重为正常值，比较50例VLBWI在出生、出院时及纠正胎龄40周时的小于胎龄儿（small for gestational age，SGA）发生率；分析喂养方式、并发症、辅助治疗等对VLBWI生长赶超的影响。结果 50例VLBWI在纠正胎龄40周时的体重为（3290±640）g，与同胎龄足月儿比较差异无统计学意义（P〉0．05）。50例VLBWI出院时SGA所占比例为64．0％（32／50），明显高于出生时的24．0％（12／50）和纠正胎龄40周时的32．0％（15／50），P均〈0．05。出生时SGA（OR=0．035，95％CI0．003-0．487）、低T3综合征（OR=0．101，95％CI0．013～0．774）及长期使用静脉营养（OR=0．307，95％CI0．097-0．972）是导致VLBWI生长赶超失败的危险因素，而早期开展肠道喂养（OR=8．241，95％CI1．373～49．470）则有利于VLBWI的生长赶超。并发低T3综合征的VLBWI住院4周期间及出院后平均体重增长速度均低于未并发低T3综合征的VLBWI（P均〈0．05）。结论 合理的营养方案、降低并发症的发生率是VLBWI实现早期生长赶超的关键。     

The effect of maternal hemoglobin concentration on fetal birth weight according to trimesters

Objective: To investigate the relationship between fetal birth weight and maternal hemoglobin concentrations in different trimesters.

Methods: This prospective cross-sectional study comprised 329 women, monitored and delivered between January 2013 and January 2014 in our clinic. Hemoglobin concentrations in all trimesters and all birth weights of the newborns were recorded. Comparisons and correlations were made of the maternal hemoglobin concentrations and birth weights in each trimester.

Results: A positive correlation was determined between fetal weight and increased first trimester maternal hemoglobin concentration (p: 0.025). No correlation was found between fetal weights and second and third trimester hemoglobin concentrations (p?=?0.287, p?=?0.298, respectively). When the effect of independent factors on fetal weight was investigated, it was determined that birth week and first trimester hemoglobin levels were the factors of most influence.

Conclusions: Low hemoglobin concentrations in the first trimester of gestation seem to be associated with low fetal birth weights. Anemia can directly cause poor in utero fetal growth due to inadequate oxygen flow to the placental tissue or it can be an indirect indicator of maternal nutrition deficiency. In both circumstances, this study reveals that treatment of anemia before and in the early stages of pregnancy is directly correlated with better fetal outcomes.     

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.     

Potential risks and benefits of antenatal corticosteroid therapy prior to preterm birth in pregnancies complicated by severe fetal growth restriction

The antepartum administration of fluorinated corticosteroids for fetal maturation represents the most important clinical contribution in the battle against prematurity. This treatment reduces the risk of neonatal death and handicap. It is also known that on corticosteroid exposure, fetuses are subjected to transiently increased physiologic and metabolic demands. Healthy fetuses are able to cope, although emerging evidence suggests this may not be the case with severely growth-restricted fetuses. This review presents evidence of efficacy and safety pertaining to corticosteroid administration in fetal growth restriction–affected pregnancies, offers guidance to clinicians, and points out questions that still need answers.     

Is there a relationship between the grade of maternal hydronephrosis and birth weight of the babies?

Mild hydronephrosis may be present in upto 90% of pregnancies. The degree of hydronephrosis was determined by maximal calyceal diameter (MCD). The aim of this study is to investigate whether there is a relationship between grade of maternal hydronephrosis and birth weight of the babies. Subjects were examined in three groups: group 1 MCD of 5–10?mm (grade I), group 2 10–15?mm (grade II) and group 3 patients >15?mm (grade III). There were 45, 30, 13 patients in the groups, respectively. Estimated fetal weight (EFW) at the time that hydronephrosis was diagnosed, birth weight and duration of pregnancy were compared. The average birth weight of the babies was not statistically different in the three groups (p?>?0.05), but there was a statistically significant difference in fetal weights at the time of diagnosis (p?=?0.02). The grade of maternal hydronephrosis does not affect the duration of pregnancy.     

脂联素和内脂素与胎儿生长发育的关系

目的 探讨脂肪因子--脂联素和内脂素与胎儿生长发育的关系.方法 收集2007年6月至12月北京军区总医院妇产科住院分娩的产妇42例,其中分娩胎儿生长受限(FGR)儿14例(FGR组),分娩巨大儿14例(巨大儿组),分娩出生体重正常新生儿14例(对照组).采用酶联免疫吸附试验(ELISA,双抗体夹心法)检测3组产妇血和新生儿脐血中的脂联素和内脂素的水平,并分析新生儿脐血中脂联素和内脂素水平与产妇血中水平的相关性.结果 (1)FGR组产妇血中内脂素水平为(41.4±5.5)μ/L,明显高于对照组的(34.7±4.9)μ/L和巨大儿组的(37.3±4.4)μ/L,分别比较,差异均有统计学意义(P<0.01,P<0.05);巨大儿组产妇血中脂联索水平为(4.1±1.3)mg/L,显著低于对照组的(6.6±1.5)mg/L和FGR组的(6.4±1.3)mg/L,分别比较,差异均有统计学意义(P均<0.01).(2)FGR组新生儿脐血中内脂素水平为(58.1±7.6)μ/L,明显高于对照组的(42.6±7.8)μ/L和巨大儿组的(48.5±9.1)μ/L,分别比较,差异均有统计学意义(P<0.01,P<0.05);巨大儿组新生儿脐血中脂联素水平为(6.5±1.3)mg/L,低于对照组的(7.7±1.5)mg/L和FGR组的(7.7±1.0)mg/L,分别比较,差异均有统计学意义(P均<0.05).(3)脐血中内脂素水平高于产妇血中的水平,两者呈显著正相关关系(r=0.720,P<0.01);脐血中脂联素水平略高于产妇血中的水平,两者无明显相关性(r=0.301,P>0.05).结论 内脂索水平的升高可能与FGR的发生有关,脂联素水平的降低可能与巨大儿的发生有关.     

Predicting preterm birth: Cervical length and fetal fibronectin

Spontaneous preterm birth remains the leading cause of neonatal morbidity and mortality worldwide, and accounts for a significant global health burden. Several obstetric strategies to screen for spontaneous preterm delivery, such as cervical length and fetal fibronectin measurement, have emerged. However, the effectiveness of these strategies relies on their ability to accurately predict those pregnancies at increased risk for spontaneous preterm birth (SPTB). Transvaginal cervical shortening is predictive of preterm birth and when coupled with appropriate preterm birth prevention strategies, has been associated with reductions in SPTB in asymptomatic women with a singleton gestation. The use of qualitative fetal fibronectin may be useful in conjunction with cervical length assessment in women with acute preterm labor symptoms, but data supporting its clinical utility remain limited. As both cervical length and qualitative fetal fibronectin have limited capacity to predict preterm birth, further studies are needed to investigate other potential screening modalities.     

The secular growth acceleration: does it appear during fetal life?

Abstract

Objective: To test if secular growth acceleration occurs during fetal life.

Methods: ANOVA Kruskal–Wallis and Mann–Whitney U-test have been used for the biometric characteristics comparison of nowadays fetal population with those three decades ago and to test the hypothesis about the existence of secular growth acceleration during fetal life. For this purpose, we first calculated mean values of particular biometric parameters for the whole pregnancy. During the period 2002–2009 biparietal diameter, fetal length and abdominal circumference measurements in singleton uncomplicated pregnancies between 22 and 41 gestational weeks were obtained. Gestational age was estimated according to Naegele's rule and confirmed with an early ultrasound examination. Pregnancies with fetal cromosomopathies and malformations were excluded as well as those resulting in perinatal death.

Results: There were no statistically significant differences of the examined fetal biometric parameters measured by ultrasound between contemporary fetal population and those from 35 years ago.

Conclusion: Our investigation did not undoubtedly prove that significant changes of fetal biometric parameters occurred in the last three decades. It is possible that secular growth acceleration does not exist in prenatal period but also the observed time period could have been short for this phenomenon to manifest.     

Ultrasound diagnosis and management of intra-uterine growth restriction

Intrauterine growth restriction (IUGR) is one of the clinically important conditions to pay full attention to the fetus in womb. However, the process in diagnosing IUGR in daily clinical medicine has not been clarified. In research fields, most studies have been carried out from a retrospective point of view. In other words, the clinical data analysis was done by using the cases delivered as light for date (LFD). As long as the IUGR is not equal to LFD, the prospective point of view for diagnosing IUGR is required in clinical medicine. In this paper, we discussed how to predict and diagnose presumable growth retardation. Usually, ultrasound measurement and fetal weight estimation are used for diagnosis. We introduce one of the promising ways of standardizing fetal growth expressed by the “deviation” from the mean value. Growth velocity was also standardized by means of calculating the index of the deviation trend divided by gestational weeks.