Fetal Kidney Length Research Articles

ULTRASOUND MEASUREMENT OF FETAL KIDNEY LENGTH AS A PARAMETER FOR GESTATIONAL AGE DETERMINATION

Background: Accuracy in estimation of gestational age (GA) has become more demanding as technology used in ultrasonography has become more advanced. Patient’s expectations have also increased and they expect exact estimations to plan their pregnancies. Mean fetal kidney length (MFKL) alone or in combination with other biometric indices can be used for estimating GA more precisely. Objective: To measure the length of fetal kidney in normal singleton pregnancies in late second and early third trimesters, its correlation with GA derived from the first day of patient known last menstrual period (LMP) and comparison with GA derived from other conventional biometric methods. Patients and methods: This study was a prospective observational study, conducted at the department of Obstetrics & Gynecology, Obstetrics & Gynecology Hospital, Assiut, 500 pregnant females were enrolled in this study from March 2018 to March 2020. Those women underwent measurement of the right and left kidneys and mean was taken. Comparison between gestational ages was determined by LMP. In addition, mean fetal kidney length as well as between mean fetal kidneys length and other fetal biometric indices was done. Results: Baseline data of enrolled women (n= 500) mean age of those women was 26.31 ± 4.87 years. Median parity and abortion was 2 with range of both was between 0-6 and 0-8 times, respectively. Mean gestational age was 30.29 ± 3.34 weeks while mean body mass index was 19.84 ± 1.20 kg/m2. Average fetal kidney length was 29.88 ± 3.33 mm. Gestational ages based on different fetal biometric indices. Age by date had strong positive significant correlation with different fetal indices but the strongest correlation was observed with mean fetal kidney length (r= 0.96, P< 0.001). Correlation between gestational age by date and expected age by MFKL based on regression equation. That there was significant strong positive correlation between gestational age and expected age by MFKL (r= 0.97; P< 0.001). Conclusion: Mean fetal kidney length can be used as an accurate new parameter for estimation of gestational age in combination with BPD, HC, AC & FL especially in late second and early third trimester (beginning from 24th week – 34th week). Using regression equation: Gestational age by date (weeks) = 1.56+ 0.97 (MKL in mm).

Evaluation of ultrasonographic fetal kidney length for gestational age detection in late second and third trimesters

Accurate estimation of gestational age is necessary to obtain materials for different tests as well as to interpret the results of these tests.Unfortunately sometimes calculation of EDD based on LMP becomes very difficult when (a) The menstrual cycle is irregular; (b) Patient fails to remember LMP or reports inaccurately (c) Pregnancy occurs during lactational amenorrhoea &amp; (d) if patient have bleeding in early pregnancy. After 24 weeks the symphysio-fundal height in cm. approximates to the number of weeks up to 36 weeks of gestation. But a number of factors influence the measurement including multiple gestation, IUGR, diabetic pregnancy, maternal size, variation in fetal lie &amp; engagement as well as inter &amp; intra observer measurement variation.Ultrasonic measurement of fetal biometry (CRL, BPD, FL) are considered to be reliable when they are performed in first &amp; early 2nd trimester (&lt;24 weeks). In this study, we aimed to evaluate the accuracy of ultrasonographic fetal kidney length measurement as a new parameter for estimation of gestational age in late second and third trimester in correlation to other commenly used parameters as, BPD, FL, AC. This study was conducted on 122 pregnant women attending antenatal care clinics of Obstetrics and Gynecology department Soliman Fakeeh Hospital, KSA. All were in the late second and third trimester (between 24-40 weeks) of gestation. Cases included in the study were divided into four gestational age groups with four weeks interval. The length of the fetal kidney was measured. The mean gestational age was calculated on the bases of biparietal diameter (BPD).femur length (FL) and abdominal circumference (AC). The fetal kidney measurements were obtained by the same sonographer to avoid interobserver variation using (GE machine E8) and were compared with gestational age using statistical analysis No statistically significant differences were found between the right and the left renal measurements in cases in which the two kidneys were imaged In this study, during the second and third trimester the mean kidney length showed gradual rate of increase. the mean kidney length was found to be 30.52.1 mm at mean gestational age of 26weeks and became at the mean gestational age of34 weeks, 40.4103 mm(:(±1.98) and at mean gestational age of 38 week it measured44.41mm((±2.1). In addition, we found a positive correlation between kidney length and gestational age. We suggested regression Formula to calculate it. Conclusion: Throughout this study, we can conclude that Fetal kidney length could be used with accuracy in the late second and third trimester especially in women who are uncertain of date of LMP and are booked late for ANC.however its accuracy is decreased when we use it in late third trimester.Other ultrasonographic parameters used for estimation of the gestational age as BPD ,AC are less satisfactory ,when compared with femur length and kidney length.

Study of fetal kidney size by ultrasonography at different gestational age

Normal fetal kidney dimensions are necessary to diagnose fetal kidney abnormalities. The maximum fetal renal growth occurs during 26-34 weeks gestation. Fetal kidney length correlates well with gestational age. Aim of the present study is to measure fetal kidney size at 30 and 38 weeks of gestation in singleton pregnancy. No statistically significant difference was found in the mean parameters of right and left kidney at a particular gestational age (p?0.05) in this study. The mean length in mm of fetal kidneys was slightly longer than the approximate gestational age in weeks. Keywords: Fetal kidney, Ultrasound, Gestational age.

Foetal Kidney Length Can Be A New Parameter For Determination of Gestational Age in Third Trimester

Gestational age assurance is one of the best strides in the administration of the timing of pregnancy and subsequent diminishing in perinatal mortality due to preterm conveyances. There is no single boundary to assess the gestational age. The utilization of ultrasound (US) biometric routine boundaries, including biparietal width (BPD), head outline (HC), stomach circuit, femoral length (FL), and fetal weight, is obligatory at all pregnancies beginning from 20 weeks. However, at late incubation , these boundaries are not exact. This examination expected to assess the precision of fetal kidney length by ultrasonography in assessing gestational age in third trimester. Techniques: This investigation is cross sectional examination that was done at Benha University clinic during the period from March 2019 to March 2020.Routine U/S assessment and kidney assessment. Estimations of all fetal biometric boundaries were acquired. Results: When contrasting the determined GA and LMP with various boundaries, the mean of LMP GA was (36.5±2.6), BPD GA was (36.0±2.72), HC GA was (35.8±2.70), AC GA was (35.5±2.9), FL GA was (36.5±2.73).There were measurably critical positive connection between's mean fetal kidney length and (biparietal breadth (BPD), BPD GA, head outline (HC), HC GA, stomach boundary (AC), AC GA, femoral length (FL) and FL GA. The current investigation determined a condition for assessment of the gestational age from the fetal kidney length (FKL) with SE ±2.4 days. End Fetal kidney length increments with increment in fetal gestational age (FGA) and shows incredible intra and bury class connection coefficient which recommends great understanding and reproducibility of estimations.

The Role of Fetal Kidney Length and Fetal Transverse Diameter of Heart in Prediction of Gestational Age

Objective: Currently there is no single ultrasonological parameter for accurate estimation of gestational age in third trimester. The present study is undertaken to validate the fetal kidney length and fetal transverse diameter of heart measurement as a measurement of fetal growth with less variability. Materials &amp; Methods: It is a cohort study conducted in Department of Obstetrics and Gynaecology, NEIGRIHMS from 2015 to 2016. 224 women with singleton pregnancies and sure of LMP were enrolled. Each woman underwent minimum three ultrasonographic measurements- at first trimester for gestational age by CRL, at second trimester with fetal conventional biometry, at third trimester with Fetal kidney length, transverse diameter of heart and fetal conventional biometric parameters and analysed with SPSS Version22. Results: The gestational age with CRL was within three days of the menstrual age. In second trimester, conventional parameter (BPD,HC,AC,FL) were better parameters. Conventional parameter did not correspond to gestational age calculated from LMP. (BPD, R2= 0.4819, HC R2- 0.507, AC R2- 0.5175, FL R2-0.5243, Combined Conventional parameter R2- 0.5888). Fetal kidney length (R2-0.8356) and transverse diameter of heart (R2-0.8795) better correlated with gestational age. Conclusion: Kidney length and transverse diameter of heart are better predictors of gestational age in third trimester.

Fetal Kidney length as a parameter for determination of Gestational Age from 20th Weeks to term in healthy women with uncomplicated pregnancy

Fetal Kidney length as a parameter for determination of Gestational Age from 20th Weeks to term in healthy women with uncomplicated pregnancy

Fetal Kidney Length in Estimation of Gestation Age by Sonography

Fetal Kidney Length in Estimation of Gestation Age by Sonography

Sonographic estimation of gestational age from 20 to 40 weeks by fetal kidney lengths\u2019 measurements among pregnant women in Portharcourt, Nigeria

BackgroundUltrasonography has become an indispensible tool in the management of obstetric patients. Accurate determination of fetal gestational age (FGA) has posed great challenge to patient management as the accuracy of traditional biometric parameters decreases with advance in gestation age. Accuracy of fetal kidney length (FKL) in the determination of FGA at third trimester has been documented in other population. This study is aimed to create baseline reference values of fetal kidney lengths in a Nigerian population as previous studies show population specific variations.MethodsThis prospective cross sectional study was carried out on 534 pregnant women between 20 and 40 weeks of gestation who met the inclusion criteria at Diamond Biomedical Services Ltd. A pilot study was conducted on 20 patients to determine the reproducibility and reliability of ultrasound measurement of FKL. Fetal kidney lengths were calculated as mean of three separate measurements. The 5th, 50th and 95th percentiles were calculated using least squared regression analysis. Third polynomial regression models were used to establish the relationship between right and left FKL and FGA.ResultsBoth FKL measurements are highly reproducible with excellent correlation and agreement within and between sonographers. It correlates strongly with gestational age while the relationships between right and left kidney lengths with gestational age were established using the following regression equations: RKL = − 11.18 + 1.193 × FGA − 0.0350 × FGA2 + 0.00037 × FGA3 and LKL = − 12.57 + 1.332 × FGA − 0.0390 × FGA2 + 0.00040 × FGA3 for right and left kidneys respectively.ConclusionNigerian population specific baseline reference values of FKLs for the estimation of FGA should be adopted rather than relying on the Caucasians values as universal patterns.

Assessment of Fetal Kidney Length as a Parameter for Detection of Gestational Age at the Third Trimester of Pregnancy

Background: the accurate knowledge of gestational age is a keystone in an obstetrician's ability to successfully manage the antepartum care of a patient and is of critical importance in ante-natal test and successful planning of appropriate therapy or intervention. Failure can result in iatrogenic prematurity which is associated with increased perinatal morbidity and mortality. Objectives: the aim of this study is to evaluate the accuracy of fetal kidney length in estimation of gestational age in normal singleton pregnancies. Patients and Methods: observational study, the study was conducted at the antenatal outpatient clinics of Obstetrics and Gynecology at Alzahraa University hospitals and Ahmed Maher Teaching hospital in the period between December 2017 and December 2018. Approval from Ethical Committee at Al Zahraa University was taken. This study included 120 asymptomatic, pregnant women, with singleton pregnancy (30 cases at each gestational age 32, 34, 36 & 38 weeks gestation). Results: the study shows that fetal kidney length is a good indicator of gestational age and can be used alone due to its accuracy in comparison to other measurements (BPD, FL &AC) that may be changed in the third trimester. There was a significant difference between right and left kidney length through different age of gestation (The Lt KL measurement was larger than the measurement Rt KL). Gestational age in weeks is nearly equal to MKL. Conclusion: fetal kidney length correlates well with gestational age, so it can be concluded that kidney dimensions can be helpful in determining the gestational age when menstrual dates are uncertain.

Assessment of Fetal Kidney Length as a Parameter for Detection of Gestational Age at the Third Trimester of Pregnancy

Background: the accurate knowledge of gestational age is a keystone in an obstetrician's ability to successfully manage the antepartum care of a patient and is of critical importance in ante-natal test and successful planning of appropriate therapy or intervention. Failure can result in iatrogenic prematurity which is associated with increased perinatal morbidity and mortality. Objectives: the aim of this study is to evaluate the accuracy of fetal kidney length in estimation of gestational age in normal singleton pregnancies. Patients and Methods: observational study, the study was conducted at the antenatal outpatient clinics of Obstetrics and Gynecology at Alzahraa University hospitals and Ahmed Maher Teaching hospital in the period between December 2017 and December 2018. Approval from Ethical Committee at Al Zahraa University was taken. This study included 120 asymptomatic, pregnant women, with singleton pregnancy (30 cases at each gestational age 32, 34, 36 & 38 weeks gestation). Results: the study shows that fetal kidney length is a good indicator of gestational age and can be used alone due to its accuracy in comparison to other measurements (BPD, FL &AC) that may be changed in the third trimester. There was a significant difference between right and left kidney length through different age of gestation (The Lt KL measurement was larger than the measurement Rt KL). Gestational age in weeks is nearly equal to MKL. Conclusion: fetal kidney length correlates well with gestational age, so it can be concluded that kidney dimensions can be helpful in determining the gestational age when menstrual dates are uncertain.

Ultrasonographic evaluation of fetal kidney length as a reliable parameter for estimation of gestation age in 2nd &amp; 3rd trimester

The fetal Kidney length can be used in estimation of gestational age. In late 2nd and 3rd trimester both kidneys can be visualized easily and can be measured accurately. In late 2nd and 3rd trimester the fetal kidney length can be used as an investigational tool alone or may be in addition of other parameter in estimation of gestational age. The most commonly used parameters used by sonologist can predict gestational age in 1st and 2nd trimester. But as pregnancy advances, the accuracy of these parameters decreased. The length of fetal kidneys in mm collaborates very nicely with gestational age in weeks&#x0D; Objective: To evaluate that fetal kidney length is a reliable parameter for gestational age estimation in 2nd and in 3rd trimester of pregnancy.&#x0D; Methods: 371 healthy, pregnant females with a normal fetus were included in this study. A standard 2nd and 3rd trimester ultrasound examination was done. In addition to the standard biometric parameters, both fetal kidneys length were also measured. The collected data was subjected to statistical analysis.&#x0D; Results: This study finding confirmed that fetal kidney length can be used as standard parameters alone or in addition with other routine parameters for estimation of gestational age in late 2nd and 3rd trimester. The Pearson correlation coefficient r=0.988 which showed a strong correlation with kidney length and gestational age and p value is (0.00)&#x0D; Conclusion: Fetal kidney length estimates gestational age as accurate as other standard traditional parameters. It is more accurate in late 2nd &amp; 3rd trimesters of pregnancy when other parameters are not much reliable. It is easy to detect and measure.&#x0D; Int. J. Appl. Sci. Biotechnol. Vol 7(1): 108-113

Ultrasonic determination of gestational age by assessment of fetal kidney size in the third trimester in southwest Nigeria.

To determine the strength of association between fetal kidney measurements and gestational age (GA) in third-trimester pregnancies. In a cross-sectional study in Ile-Ife, Nigeria, women in the third trimester of a singleton pregnancy who were sure of the date of their last menstrual period or had an early pregnancy scan were recruited consecutively in 2012. Standard biometric measurements were taken, along with fetal kidney length (FKL), anteroposterior diameter (FKAPD), and transverse diameter (FKTD). Fetal kidney volume (FKV) was calculated via the ellipsoid formula. Data were analyzed by Pearson correlation and multivariate linear regression. In total, 470 women were recruited. Compared with standard biometric parameters, renal parameters showed better correlation with GA. Among the standard parameters, femur length showed the strongest correlation with GA. FKL and FKV showed stronger positive correlation with GA as compared with FKTD and FKAPD. In multivariate linear regression modeling, FKL alone predicted GA with accuracy of ±10.1days, whereas a combination of standard and kidney parameters predicted GA with better accuracy of ±8.0days. Compared with standard biometric parameters, fetal renal parameters correlated better with GA in the third trimester. Among the renal parameters, FKL correlated most strongly with GA.

Determination of gestational age by ultrasonographic measurement of fetal kidney length during third trimester of pregnancy

Objective The aim of accurate estimation of gestational age is reduction of fetal and maternal morbidity and mortality as much as possible. The routine fetal biometry ultrasound (US) measurement at third trimester is not adequate all times; for this purpose, new parameters must be developed. Average fetal kidney length (FKL) is one of them and may add value as a single parameter. Design A prospective study to assess the gestational age at the third trimester using FKL US measurement was done. Patients and methods Seventy-five noncomplicated pregnant women at third trimester (25 as a training sample and 50 as a validating sample) were included in the study. All of them had accurate date of last menstrual period and had regular follow-up at the Department of Obstetrics and Gynecology. Routine US biometry and FKL were done. The training sample was used to calculate a regression equation of gestational age by FKL, and then the validation of the regression equation was done on the validating sample. Main outcome measures To compare the results of gestational age by FKL measurement derived from the regression equation to gestational age by sure last menstrual period date to calculate accuracy and standard error of the estimate. Results There is a strong correlation between gestational age by date and estimated average kidney length in the third trimester, using linear regression analysis (Pearson's r = 0.871;P > 0.001). The derived regression equation [gestational age using FKL (days)=51.1165 + 5.02 × average kidney length (mm)] could estimate the actual gestational age with an accuracy of ±6.4 days (SE of the estimate). Conclusion Average FKL can be used as a new single parameter with some degree of confidence for determination of gestational age at the third trimester.

Fetal Kidney Length as an Independent Estimator of Gestational Age: A Cohort Study of a Population of Yoruba Women in Lagos Nigeria

Background: Fetal kidney length (FKL) can be used to estimate gestational age (GA) yet there is a paucity of data on its precision. Aim: To determine the precision and usefulness of FKL as GA predictor. Methods: In the prospective study, sonographically measured FKL was used to estimate GA while its standard error as GA estimator was calculated. Result: The rate of kidney growth was 1.2 mm per week; mean FKL was 37.7 ± 2.9 mm. The mean right and left FKL was 37.5 ± 3.6 mm and 37.9 ± 3.1 mm, respectively. Correlation between GA and FKL was positive (r = 0.9870; p &lt; 0.0001); FKL was more precise than the biparietal diameter and abdominal circumference as GA estimator (standard error of estimation = ±6.6 days). Conclusion: Sonographically measured FKL was precise and useful as an independent GA estimator in the third trimester of pregnancy in a population of Yoruba women in Lagos Southwest Nigeria.

Accuracy of the fetal kidney length measurement by ultrasonography in the determination of the gestational age in pregnancy

Background Definitive calculation of gestational age (GA) forms the basis for rendering standard antenatal care. Depending on the period of pregnancy, various parameters are in use for GA calculation. But none of those fetal biometric indices were observed to be reliable with progression of pregnancy beyond second trimester. Various studies claiming fetal kidney length (FKL) as a reliable index to calculate GA in late trimester have prompted this study to validate and compare this claim with other indices among Indian women in late pregnancy. Materials and Methods This study was done on 100 singleton uncomplicated late pregnant women who knew their last menstrual period definitely. A blinded sonographic process was executed wherein one sonologist measured traditional biometric indices like biparietal diameter, head circumference, abdominal circumference, and femur length and calculated GA. While the other measured only FKL and calculated GA. The results were descriptively analyzed. The correlation of each of the index in accurately calculating GA was done by Pearson's correlation test. Results FKL was 28.12 mm at 28 weeks and it progressively increased along with GA and it was 40.10 mm at 40 weeks’ gestation. The Pearson's correlation coefficient of r = 0.926 was observed to be significant compared with other fetal biometric indices measured. Conclusion FKL could be used as a single index to calculate GA in third trimester. Combined with other sonographic fetal indices FKL might increase the accuracy of GA calculation in late pregnancy.

Fetal Kidney Length for Determining Gestational Age in Third Trimester

Introduction: Accurate gestational age assessment is important in obstetric care. Ultrasonography plays a significant role in determination of Gestational Age. The ultrasonographic parameters used for GA determination are Crown rump Length, Biparietal diameter, Head circumference, and abdominal circumference and Femur length. Fetal kidney length (FKL) is one of the emerging parameter in estimation of gestational age. Renal length in mm is identified to approximate the gestational age in weeks. The present study is aimed to corroborate that FKL as a good parameter for gestational age estimation in third trimester. Objective: Is to ascertain the precision of the ultrasonographic 'foetal kidney length' measurement as a reliable parameter for determination of GA in third trimester. Material and Methods: One year Cross-Sectional and an Observational Study was conducted on 171 antenatal women in the third trimester after corroborating the gestational age by first trimester ultra sound and GA by LMP. Ultrasound measurements of Foetal kidney length were taken and correlation with last menstrual period gestational age and with other parameters (BPD, HC, AC, FL) were evaluated. Results: This study showed a good correlation of Mean kidney length with GA by LMP of (r=0.991) than the rest of the parameters, HC(r=0.836), FL(r=0.853), AC(r=0.853), BPD (r=0.734) with p value=0.000 for all the parameters. Conclusion: This study confirms that the fetal kidney length measurement is a reliable ultrasonographic parameter for estimating the gestational age accurately in the 3rd trimester and also it is observed that the correlation is increased when used along with other parameters.

Estimation of gestational age by sonographic fetal kidney length

Estimation of gestational age by sonographic fetal kidney length

Foetal Kidney Development and Amniotic Fluid Formation in Upper Egyptian Pregnancies

AbstractBackground: The foetal kidney development is important for its normal function. The Amniotic Fluid Index (AFI) is used to assess the amniotic fluid volume. The main source of the amniotic fluid is the foetal urine.Aim of the Work: To establish reference values for the foetal kidney length and the AFI throughout the second and third trimesters of the normal Upper Egyptian pregnancies and to clarify the correlations between these measurements.Subject and Methods: An ultrasonographic examination was performed to measure the foetal kidney length and the AFI on 232 normal pregnant women from the 14th week to the 42nd week of gestation. The correlations between the measurements were analysed statistically.Results: The foetal kidney length increased gradually with gestation. There was a significantly positive correlation between the foetal kidney length and the gestational age. The linear regression showed that the gestational age could be assessed by using the foetal kidney length with an accuracy of ±1.078 week. From the 14th week, the AFI increased progressively until the 24th week. There was a positive correlation between the AFI and the gestational age and between the AFI and the foetal kidney length. From the 25th week to the 32nd week, the AFI demonstrated little variations. From the 33rd week, the AFI declined gradually. There was a negative correlation between the AFI and the gestational age and between the AFI and the foetal kidney length.Conclusion: The present study introduces reference values for both the foetal kidney length and the AFI in the normal Upper Egyptian pregnancies. It also discusses the correlation between the foetal kidney length and the AFI as early as the second trimester of pregnancy. At first, it is a direct correlation. Then, it shows minimal variations. Finally, it becomes an inverse one. The obtained information could be usefully applied clinically.

Ultrasound measurement of fetal kidney length in normal pregnancy and correlation with gestational age.

Belated booking for antenatal care remains a common practice among pregnant women in developing countries. Many of the existing conventional ultrasonographic indices used for assessing gestational age (GA) become increasingly unreliable beyond the 2nd trimester. A prospective cross-sectional study of booked healthy pregnant women with regular menstrual cycles and certain last menstrual period (LMP) were examined using ultrasound over a 6-month period. Fetal kidney length (FKL) was measured, beginning from 20 to 41 weeks of gestation. A total of 400 pregnant women were examined. The mean left FKL was slightly but significantly higher than the mean right FKL across the various weeks of gestation (P < 0.05). The mean combined FKL (MKL) was 32.18 ± 5.96 mm, with a reference range of 20.87 ± 0.75 mm to 41.41 ± 0.07 mm from 20 to 41 weeks of gestation. There was strongly positive significant correlation between MKL in millimeters and GA by the LMP in weeks (r = 0.997, P = 0.000). The standard error of prediction (SE) of GA was least for MKL (±7.17 days), followed by femur length (FL) (±8.38 days), head circumference (HC) (±9.02 days), abdominal circumference (AC) (±9.14 days), and biparietal diameter (BPD) (±10.36 days). The best multiple regression model for predicting GA included the five variables such as MKL, FL, BPD, HC, and AC, with a SE of prediction of (±6.31 days). FKL can serve as an additional reliable parameter for accurate dating of GA during obstetric scan.

Early results on canine fetal kidney development: Ultrasonographic evaluation and value in prediction of delivery time

To date there have been no studies that describe the ultrasonographic evaluation of kidney development in canine fetuses. The aim of this prospective and longitudinal study was to monitor fetal kidney development with ultrasound and use fetal kidney measurements as a complementary biometric index for estimation of gestational age. Ultrasonographic examinations were performed on 15 clinically healthy pregnant bitches every four days from 30th day of pregnancy, until visualization of the fetal renal pelvis was no longer possible. Four distinct periods of ultrasonographic canine fetal kidney development were defined. Kidney length and renal pelvis distention were measured on longitudinal plane images. The fetal kidney ranged from 0.40 cm to 2.30 cm in length, and diameter of the pelvis ranged from 0.06 cm to 0.17 cm, however by the end of gestation the renal pelvis was no longer dilated and so its diameter could not be measured. Statistical analysis confirmed a relationship between gestational age and fetal kidney growth. Ultrasonographic evaluation of fetal kidney development is simple to perform. There is a strong correlation between gestational age and kidney length, which allowed generation of an equation to estimate delivery date with high sensitivity between 48 and 52 days of pregnancy. Fetal organ development can be considered complete when the renal pelvis is no longer dilated, this finding can assist the ultrasonographer in staging the gestation by prompting examination for fetal intestinal motility which begins at the same gestational age. Measurement of fetal kidney length can be used in conjunction with other methods to estimate gestational age and predict delivery time.