Growth patterns of the heart and kidney suggest inter-organ collaboration in facultative fetal growth

Fetal Tricuspid Valve Agenesis/Atresia: Testing Predictions of the Embryonic Etiology

Tricuspid valve agenesis/atresia (TVA) is a congenital cardiac malformation where the tricuspid valve is not formed. It is hypothesized that TVA results from a failure of the normal rightward expansion of the atrioventricular canal (AVC). We tested predictions of this hypothesis by morphometric analyses of the AVC in fetal hearts. We used high-resolution MRI and ultrasonography on a post-mortem fetal heart with TVA and with tricuspid valve stenosis (TVS) to validate the position of measurement landmarks that were to be applied to clinical echocardiograms. This revealed a much deeper right atrioventricular sulcus in TVA than in TVS. Subsequently, serial echocardiograms of in utero fetuses between 12 and 38 weeks of gestation were included (n = 23 TVA, n = 16 TVS, and n = 74 controls) to establish changes in AVC width and ventricular dimensions over time. Ventricular length and width and estimated fetal weight all increased significantly with age, irrespective of diagnosis. Heart rate did not differ between groups. However, in the second trimester, in TVA, the ratio of AVC to ventricular width was significantly lower compared to TVS and controls. This finding supports the hypothesis that TVA is due to a failed rightward expansion of the AVC. Notably, we found in the third trimester that the AVC to ventricular width normalized in TVA fetuses as their mitral valve area was greater than in controls. Hence, TVA associates with a quantifiable under-development of the AVC. This under-development is obscured in the third trimester, likely because of adaptational growth that allows for increased stroke volume of the left ventricle.

Prenatal nicotine exposure was associated with long-term impact on the cardiovascular system and regulation-Review

AIM

The aim of this structured review was to discuss knowledge of nicotine use during pregnancy and long-term effects on children's cardiovascular function.

METHODS

PubMed and MEDLINE were searched for original papers that covered various forms of nicotine exposure during pregnancy and this identified 314 papers published in English from inception of the databases to 1 March 2021. The research focus was prenatal exposure that had long-term effects on the cardiovascular system. The search was expanded from the reference list of the selected papers, which identified another 17 papers.

RESULTS

The 34 original papers that were included covered 172,696 subjects from foetuses to 19 years of age. Cardiovascular autonomic dysfunction was discussed in 12 of the papers and 16 studies reported on blood pressure. The remaining studies covered structural or functional changes in arterial wall or heart. There were convincing data on autonomic dysfunction and increased blood pressure. Some data were conflicting and problems with misclassification of exposure were evident.

CONCLUSION

Prenatal nicotine exposure was associated with long-term developmental changes in the cardiovascular system and regulation. There were no safe periods, doses or nicotine products during pregnancy and women should abstain when planning a pregnancy.

Bioenergetic Evolution Explains Prevalence of Low Nephron Number at Birth: Risk Factor for CKD

There is greater than tenfold variation in nephron number of the human kidney at birth. Although low nephron number is a recognized risk factor for CKD, its determinants are poorly understood. Evolutionary medicine represents a new discipline that seeks evolutionary explanations for disease, broadening perspectives on research and public health initiatives. Evolution of the kidney, an organ rich in mitochondria, has been driven by natural selection for reproductive fitness constrained by energy availability. Over the past 2 million years, rapid growth of an energy-demanding brain in Homo sapiens enabled hominid adaptation to environmental extremes through selection for mutations in mitochondrial and nuclear DNA epigenetically regulated by allocation of energy to developing organs. Maternal undernutrition or hypoxia results in intrauterine growth restriction or preterm birth, resulting in low birth weight and low nephron number. Regulated through placental transfer, environmental oxygen and nutrients signal nephron progenitor cells to reprogram metabolism from glycolysis to oxidative phosphorylation. These processes are modulated by counterbalancing anabolic and catabolic metabolic pathways that evolved from prokaryote homologs and by hypoxia-driven and autophagy pathways that evolved in eukaryotes. Regulation of nephron differentiation by histone modifications and DNA methyltransferases provide epigenetic control of nephron number in response to energy available to the fetus. Developmental plasticity of nephrogenesis represents an evolved life history strategy that prioritizes energy to early brain growth with adequate kidney function through reproductive years, the trade-off being increasing prevalence of CKD delayed until later adulthood. The research implications of this evolutionary analysis are to identify regulatory pathways of energy allocation directing nephrogenesis while accounting for the different life history strategies of animal models such as the mouse. The clinical implications are to optimize nutrition and minimize hypoxic/toxic stressors in childbearing women and children in early postnatal development.

Evaluation of fetal heart geometry during pregnancy by three-dimensional ultrasound using the STIC rendering mode

OBJECTIVE

To determine fetal heart geometry during pregnancy using three-dimensional (3D) ultrasound and the spatiotemporal image correlation (STIC) rendering mode.

METHODS

This prospective, cross-sectional study evaluated 250 normal singleton pregnancies from 20 to 33 weeks and 6 days of gestation. STIC rendering was used to calculate the eight angles of the fetal heart: apex, base, mitral valve, tricuspid valve, left ventricle, right ventricle, left atrium, and right atrium angles. The concordance correlation coefficient (CCC) was used for intra- and inter-observer tests.

RESULTS

The average ± SD maternal age was 31.7 ± 4.9 years, and the average gestational age was 26.3 ± 4.2 weeks. There was little variation in fetal heart angles using STIC rendering according to the gestational age, with determination coefficient (R² ) values of 0.01 for the apex and mitral valve angles and <0.01 for the base, tricuspid valve, left ventricle, right ventricle, left atrium, and right atrium angles. Moderate/good intra- and inter-observer concordance was observed for the measurement of fetal heart angles using STIC rendering, and the obtained CCC varied from 0.74 to 0.93.

CONCLUSION

The fetal heart geometry did not present significant variations during pregnancy using 3D ultrasound and the STIC rendering mode.

The INTERGROWTH-21st fetal growth standards: toward the global integration of pregnancy and pediatric care

The purpose of the INTERGROWTH-21^st project was to develop international, prescriptive standards for fetal growth assessed by ultrasound and fundal height, preterm postnatal growth, newborn size and body composition, maternal weight gain, and infant development at the age of 2 years. Hence, we have produced, based on World Health Organization recommendations, the first comprehensive set of international standards of optimal fetal and newborn growth that perfectly match the existing World Health Organization child growth standards. Uniquely, the same population was followed up longitudinally from 9 weeks of fetal life to 2 years of age, with growth, health, and nutritional status assessment at 2 years supporting the appropriateness of the population for construction of growth standards. The resulting package of clinical tools allows, for the first time, growth and development to be monitored from early pregnancy to infancy. The INTERGROWTH-21^st fetal growth standards, which are based on observing >4500 healthy pregnancies, nested in a study of >59,000 pregnancies from populations with low rates of adverse perinatal outcomes, show how fetuses should grow-rather than the more limited objective of past references, which describe how they have grown at specific times and locations. Our work has confirmed the fundamental biological principle that variation in human growth across different populations is mostly dependent on environmental, nutritional, and socioeconomic factors. We found that when mothers' nutritional and health needs are met and there are few environmental constraints on growth, <3.5% of the total variability of skeletal growth was due to differences between populations. We propose that not recognizing the concept of optimal growth could deprive the most vulnerable mothers and their babies of optimal care, because local growth charts normalize those at highest risk for growth restriction and overweight, and can be valuable for policymakers to ensure rigorous evaluation and effective resource allocation. We strongly encourage colleagues to join efforts to provide integrated, evidence-based growth monitoring to pregnant women and their infants worldwide. Presently, there are 23.3 million infants born small for gestational age in low- to middle-income countries according to the INTERGROWTH-21^st newborn size standards. We suggest that misclassification of these infants by using local charts could affect the delivery of optimal health care.

Evaluation of fetal kidney growth using ultrasound: A systematic review

PURPOSE

To determine the role of ultrasound imaging in evaluating fetal kidney growth.

METHODS

MEDLINE, CINAHL and EMBASE databases were electronically searched for studies between 1996 and January 2017 and limited to English language. Studies were included if they reported on an ultrasound technique to assess fetal kidney growth and they were not a case report or case series. There was independent selection of studies by two reviewers in consensus with one other reviewer. Data were extracted by one reviewer in consensus with two other reviewers.

RESULTS

A total of 1785 articles were identified. The full text of 39 of these were assessed for eligibility for inclusion. Twenty-eight studies were then included in the review. Standard two dimensional (2D) fetal renal measurements are easy to perform, however, this review identified that most studies had some methodological limitations. The disadvantage with 2D and three dimensional (3D) fetal renal volumes are that they include the entire kidney and good reproducibility of 3D volumes has not yet been demonstrated. Currently there is limited research on fetal kidney growth in the setting of abnormal fetal growth. Research focussing directly on fetal kidney parenchyma and blood flow is scarce.

CONCLUSIONS

Some nomograms of 2D and 3D fetal kidney size and volume have been developed. Kidney length is the most popular single fetal kidney measurement; however, it does not seem to be a good indicator of growth. In IUGR fetuses, kidney length remained similar to appropriately grown fetuses whereas AP and TS dimensions were significantly decreased. New ultrasound techniques focusing on the parenchyma of the kidney and perfusion to the kidney should be explored as they may provide more meaningful information on kidney development in the fetus and future kidney function.

Ultrasound observations of subtle movements: a pilot study comparing foetuses of smoking and nonsmoking mothers

AIM

One way to assess foetal health of smokers is to ask mothers to count perceived movements, an unreliable method hiding differences in prenatal development. The aim of this pilot study was to assess subtle foetal movements in ultrasound scans and establish whether they differ in foetuses of mothers who smoked and nonsmoking mothers.

METHODS

This longitudinal pilot study recruited twenty mothers (16 nonsmoking; 4 smoking) scanned four times from 24 to 36 weeks gestation (80 ultrasound scans). Two types of fine-grained movements were coded offline and analysed using a Poisson log-linear mixed model.

RESULTS

Foetuses of smoking mothers showed a significantly higher rate of mouth movements compared to foetuses of nonsmoking mothers (p = 0.02), after controlling for maternal stress and depression. As pregnancy progressed, these differences between the smoking and nonsmoking groups widened. Differences between the two groups in the rate of foetal facial self-touch remained constant as pregnancy progressed and were borderline significant (p = 0.07).

CONCLUSION

Rates of foetal mouth movement and facial self-touch differ significantly between smokers and nonsmokers. A larger study is needed to confirm these results and to investigate specific effects, including the interaction of maternal stress and smoking. Additionally, the feasibility of this technique for clinical practice should be assessed.

Fetal kidney programming by maternal smoking exposure: effects on kidney structure, blood pressure and urinary sodium excretion in adult offspring

INTRODUCTION

Fetal programming by different insults results in low birth weight and reduction in nephron number increasing the risk for adult development of cardiovascular and renal diseases. Maternal smoking is an important modifiable adverse fetal exposure worldwide and leads to a decrease in the offspring's birth weight. Thus far, the specific adverse fetal smoking exposures and mechanisms underlying these associations on renal development and functional disorder are unclear.

METHODS

The present study investigates, in adult male rats, the effect of smoking exposure (Sk) in uteri on blood pressure (BP) by an indirect tail-cuff method using an electrosphygmomanometer, and its association with nephron structure by stereological estimation, immunohistochemical and histological techniques, in parallel with kidney function creatinine and lithium clearance.

RESULTS

The current study showed in a 16-week old Sk offspring enhanced arterial blood pressure associated with, reduced urinary sodium excretion and higher TGF-β1 glomerular expression. Sk glomeruli also presented an upregulated collagen and fibronectin deposition intrinsically related to fibrotic process as compared to age-matched control group.

CONCLUSION

Here, we demonstrate that fetal-programmed Sk offspring present pronounced glomerular TGF-β1 and fibrotic marker expression that may, subsequently, promote a glomerular epithelial-mesenchymal transition activated process in an Sk offspring. Although the precise mechanism responsible for the subsequently renal morphological and functional response in Sk offspring is incompletely known, the current data suggest that changes in renal function are conducive to excess sodium tubule reabsorption that is associated with enhanced TGF-β1, fibronectin and collagen deposition, intrinsically related to fibrotic process, might potentiate the programming of adult hypertension.

Oxidative stress, mitochondrial perturbations and fetal programming of renal disease induced by maternal smoking

An adverse in-utero environment is increasingly recognized to predispose to chronic disease in adulthood. Maternal smoking remains the most common modifiable adverse in-utero exposure leading to low birth weight, which is strongly associated with chronic kidney disease (CKD) in later life. In order to investigate underlying mechanisms for such susceptibility, female Balb/c mice were sham or cigarette smoke-exposed (SE) for 6 weeks before mating, throughout gestation and lactation. Offspring kidneys were examined for oxidative stress, expression of mitochondrial proteins, mitochondrial structure as well as renal functional parameters on postnatal day 1, day 20 (weaning) and week 13 (adult age). From birth throughout adulthood, SE offspring had increased renal levels of mitochondrial-derived reactive oxygen species (ROS), which left a footprint on DNA with increased 8-hydroxydeoxyguanosin (8-OHdG) in kidney tubular cells. Mitochondrial structural abnormalities were seen in SE kidneys at day 1 and week 13 along with a reduction in oxidative phosphorylation (OXPHOS) proteins and activity of mitochondrial antioxidant Manganese superoxide dismutase (MnSOD). Smoke exposure also resulted in increased mitochondrial DNA copy number (day 1-week 13) and lysosome density (day 1 and week 13). The appearance of mitochondrial defects preceded the onset of albuminuria at week 13. Thus, mitochondrial damage caused by maternal smoking may play an important role in development of CKD at adult life.

Fetal Smoke Exposure and Kidney Outcomes in School-Aged Children

BACKGROUND

Fetal smoke exposure may result in developmental adaptations that permanently affect the developing kidney. In this study, the associations of maternal and paternal smoking during pregnancy with childhood kidney size and function were assessed.

STUDY DESIGN

Prospective cohort study from fetal life onward.

SETTING & PARTICIPANTS

This study was conducted in a group of 5,622 children in Rotterdam, the Netherlands.

PREDICTORS

Maternal and paternal smoking were assessed during pregnancy by questionnaires.

OUTCOMES & MEASUREMENTS

At a median age of 6.0 (5th-95th percentile, 5.6-7.9) years, we measured childhood kidney volumes, estimated glomerular filtration rate (eGFR), and albumin-creatinine ratio.

RESULTS

The confounder model, which included size at birth, shows that compared with children from mothers who did not smoke during pregnancy, those from mothers who continued smoking during pregnancy had smaller combined kidney volumes at the age of 6 years. The strongest effect estimate was observed for mothers who smoked 5 or more cigarettes per day during pregnancy (difference for combined kidney volume, -2.80 [95% CI, -5.15 to -0.45] cm(3)). Similarly, continued maternal smoking during pregnancy also was associated with a lower eGFR in childhood (difference, -2.25 [95% CI, -3.70 to -0.79] mL/min/1.73 m(2)). First-trimester-only smoking was associated with a higher risk of increased albumin-creatinine ratio (OR, 1.45; 95% CI, 1.05-2.01). Among mothers who did not smoke during pregnancy, paternal smoking was associated with smaller childhood combined kidney volume (difference, -1.78 [95% CI, -3.48 to -0.07] cm(3)), but not with childhood kidney function measures.

LIMITATIONS

Smoking behavior was measured with questionnaires. Follow-up measurements were available for only 70% of the children.

CONCLUSIONS

Continued maternal smoking during pregnancy is associated with smaller combined kidney volume and lower eGFR in school-aged children. Stronger effect estimates for maternal versus paternal smoking suggest that intrauterine adaptive responses may play a role as underlying mechanisms.

New technique for assessing fetal heart growth using three-dimensional ultrasonography: description of the technique and reference curves

OBJECTIVE

To describe a new technique for assessing fetal growth using three-dimensional ultrasonography (3DUS) using the extended imaging virtual organ computer-aided analysis (XI VOCAL) software and its respective reference curves.

METHODS

We conducted a cross-sectional study on 303 normal singleton pregnancies between their 20th and 34th weeks. To assess fetal heart growth, we used the XI VOCAL software with 10 planes in which the reference lines (beginning and end) were placed at the cardiac apex, the output level of the vessels and the base above the diaphragm, respectively. To assess the correlation between distance and interval, polynomial regressions were performed with adjustments using the coefficient of determination (R(2)). To assess the inter-observer reproducibility, we used the intraclass correlation coefficient (ICC).

RESULTS

The mean distance between the apex and the base of the fetal heart ranged from 14.41 ± 1.24 mm to 26.24 ± 2.62 mm between the 20th and 34th weeks, respectively. The mean interval between the apex and the base of the fetal heart ranged from 1.56 ± 0.13 mm and 2.94 ± 0.30 mm between the 20th and 34th weeks, respectively. We observed good correlation of distance and interval with the gestational age, with R(2) = 0.73 and 0.74, respectively. We observed a good inter-observer to the interval and distance with ICC = 0.983 and 0.996, respectively.

CONCLUSION

We described a new technique for assessing fetal heart growth using 3DUS and determined reference curves for the distance and interval between the 20th and 34th weeks of pregnancy.

Maternal smoking during pregnancy and kidney volume in the offspring: the Generation R Study

An adverse fetal environment leads to smaller kidneys, with fewer nephrons, which might predispose an individual to the development of kidney disease and hypertension in adult life. In a prospective cohort study among 1,072 children followed from early fetal life onward, we examined whether maternal smoking during pregnancy, as a significant adverse fetal exposure, is associated with fetal (third trimester of pregnancy, n = 1,031) and infant kidney volume (2 years of age, n = 538) measured by ultrasound. Analyses were adjusted for various potential confounders. Among mothers who continued smoking, we observed dose-dependent associations between the number of cigarettes smoked during pregnancy and kidney volume in fetal life. Smoking less than five cigarettes per day was associated with larger fetal combined kidney volume, while smoking more than ten cigarettes per day tended to be associated with smaller fetal combined kidney volume (p for trend: 0.002). This pattern was not significant for kidney volume at the age of 2 years. Our results suggest that smoking during pregnancy might affect kidney development in fetal life with a dose-dependent relationship. Further studies are needed to assess the underlying mechanisms and whether these differences in fetal kidney volume have postnatal consequences for kidney function and blood pressure.

Early influences on cardiovascular and renal development

The hypothesis that a developmental component plays a role in subsequent disease initially arose from epidemiological studies relating birth size to both risk factors for cardiovascular disease and actual cardiovascular disease prevalence in later life. The findings that small size at birth is associated with an increased risk of cardiovascular disease have led to concerns about the effect size and the causality of the associations. However, recent studies have overcome most methodological flaws and suggested small effect sizes for these associations for the individual, but an potential important effect size on a population level. Various mechanisms underlying these associations have been hypothesized, including fetal undernutrition, genetic susceptibility and postnatal accelerated growth. The specific adverse exposures in fetal and early postnatal life leading to cardiovascular disease in adult life are not yet fully understood. Current studies suggest that both environmental and genetic factors in various periods of life may underlie the complex associations of fetal growth retardation and low birth weight with cardiovascular disease in later life. To estimate the population effect size and to identify the underlying mechanisms, well-designed epidemiological studies are needed. This review is focused on specific adverse fetal exposures, cardiovascular adaptations and perspectives for new studies.

Analysis of the harmonized growth pattern of fetal organs by multidimensional scaling and hierarchical clustering

The development of an organ may be affected by various growth and differentiation factors released from other organs. These factors are believed to have important effects on the development of multiple organs. To detect and analyze harmonized development among multiple organs, similarities in growth patterns among fetal organs were examined using multivariate analysis. Ninety human fetuses obtained from the Kyoto Collection of Human Embryos were dissected. Harmonized development of organs was evaluated by multidimensional scaling and cluster analysis using measurements (length, width, height, and weight) of the fetal organs. Similar growth patterns were observed between the brain, including cerebrum, diencephalon, and midbrain (cerebrum-to-midbrain [Cer-Mid]), and pituitary (crown-rump length [CRL] 95-155 mm). Further, similar growth patterns were observed between the liver and Cer-Mid and cerebellum (Cb; CRL 156-202 mm), and between Cer-Mid and Cb (CRL 203-253 mm). Similarities in growth patterns were also observed between right and left lungs (CRL 99-235 mm) and between the aorta and heart (CRL 139-187 mm), but not between the lung and pulmonary trunk. These findings revealed synchronized development among fetal organs and suggested a functional and structural relationship among different organs in the prenatal period. These relationships include the existence of common factors in organ development, such as cross-talk mediated by humoral factors, and the presence of an anatomical and functional relationship in the fetal circulatory system.

Cardiac structures track during the first 2 years of life and are associated with fetal growth and hemodynamics: the Generation R Study

BACKGROUND

The aim of this study is to examine whether cardiac size and function track in early childhood and are associated with fetal and early postnatal growth and blood flow characteristics.

METHODS

This study was embedded in a population-based prospective cohort study from fetal life onward. Fetal growth and fetal and placental blood flow parameters in second and third trimester of pregnancy were measured by ultrasound and Doppler. Left cardiac structures and shortening fraction were measured postnatally at the ages of 1.5, 6, and 24 months. Analyses were based on 1,001 children.

RESULTS

Left ventricular mass tended to remain in the lowest and highest quartiles from the age of 1.5 to 24 months (odds ratio 1.70, 95% confidence interval [CI] 1.10-2.63) and 2.15 (95% CI 1.41-3.30), respectively. Similar results were found for aortic root diameter and left atrial diameter. Birth weight was positively associated with aortic root diameter (0.08 mm, 95% CI 0.01-0.17; per SD increase) and left ventricular mass (0.65 g, 95% CI 0.09-1.21; per SD increase). Resistance indices of the umbilical and uterine arteries showed weak tendencies toward inverse associations with left cardiac structures. Fetal cardiac output was positively associated with both left atrial diameter (increase of 1.96 mm, 95% CI 1.28-2.64; per mL/min increase) and left ventricular mass (increase of 1.79 g, 95% CI 0.35-3.22; per mL/min increase).

CONCLUSIONS

This study suggest moderate tracking of left cardiac structures during the first 2 years and that small size and hemodynamic variations in fetal life have consequences for postnatal cardiac size and function.

Prenatal Magnetic Resonance Imaging Demonstrates Linear Growth of the Human Fetal Kidneys During Gestation

PURPOSE

Although fetal kidneys have only 10% of their postnatal blood flow, fetal renal development is essential for normal postnatal function. In addition, to our knowledge it is unknown whether human fetal kidney development follows a linear or exponential evolution. We created normative magnetic resonance imaging curves for the kidney prenatal growth pattern in relation to gestational age.

MATERIALS AND METHODS

A total of 142 human fetuses at between 20 and 36 weeks of gestation underwent prenatal magnetic resonance imaging for nonurological pathology (pulmonary, cerebral or maternal abnormalities). Twins, urinary tract abnormalities, oligohydramnios or anhydramnios were excluded. T2-weighted images (single shot turbo spin-echo) were used to measure kidney variables. Bipolar and anteroposterior diameters of the 2 kidneys were measured and correlated with gestational age using linear regression analysis.

RESULTS

A linear relationship of the bipolar and anteroposterior diameters was found according to gestational age in weeks (p <0.0001). No substantial differences between growth of the left and right fetal kidneys was identified. Bipolar length of the human fetal kidney increases at an average rate of 1.24 mm per week of gestation, while anteroposterior diameter increases at 0.57 mm per week of gestation between weeks 20 and 36. This indicates that bipolar diameter increases twice as rapidly as anteroposterior diameter. Regression analysis curves showed a good fit to the measured data points (anteroposterior and bipolar measurements R2 = 0.36 and 0.58, respectively). The CIs of function variables were small, enabling their use as normative curves.

CONCLUSIONS

This prenatal magnetic resonance imaging study demonstrates linear growth of the bipolar and anteroposterior diameters of human fetal kidneys in relation to gestational age. In addition, it is clear that bipolar diameter grows twice as rapidly as anteroposterior diameter and there is less variability for bipolar diameter. These normative curves may allow us to detect abnormal fetal evolution.

Nomogram of fetal renal growth expressed in length and parenchymal area derived from ultrasound images

PURPOSE

We constructed nomograms of fetal renal length and parenchymal area derived from ultrasound images to develop a standard for normal fetal renal growth.

MATERIALS AND METHODS

Longitudinal and transverse ultrasound renal images from 216 normal fetuses (16 to 41 weeks of gestation) were evaluated to construct growth charts. We measured the parenchymal area as well as the longitudinal and transverse lengths of each kidney using computer software for image analysis. Data were separately plotted as a mean +/- 2 SD determined by polynomial regression analysis.

RESULTS

Nomograms for a renal growth chart were constructed independently for the right and left fetal kidneys. No statistically significant difference was noted between the right and left renal measurements. The polynomial regression equations for the left renal longitudinal length and parenchymal area, respectively, were y = -0.0002x(3) + 0.0139x(2) - 0.2162 x 2.3929 (r(2) = 0.9842), and y = -0.0009x(3) + 0.0724x(2) - 1.5643 x 11.68 (r(2) = 0.9779). The longitudinal and transverse fetal renal growth curves displayed significant growth associated with gestational age (p <0.001). Our data on left longitudinal renal length exhibited an intermediate level compared to 2 published Western growth charts. However, statistical comparisons revealed the differences were partially, but not universally, significant.

CONCLUSIONS

We present our nomogram of fetal renal growth expressed in length and parenchymal area. To our knowledge this is the first report of a fetal renal growth chart in Asia that includes the parenchymal area. This nomogram may serve as a valuable tool for evaluation of fetal renal growth.